How often does a solar eclipse happen? – There are two to five solar eclipses each year, with a total eclipse taking place every 18 months or so. Whether you can view that eclipse depends on where you are in the world. As the Earth rotates, the Moon’s shadow on Earth (and the view of the eclipse) travels from west to east. The route of the Moon’s umbra across Earth is called the path of totality, as it is where the total eclipse will be observed © Owen Production/ Shutterstock.com
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Do solar eclipses happen every 7 years?
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The diamond ring effect of the 2013 total solar eclipse is seen in this amazing photo by eclipse-chasing photographer Ben Cooper, who captured the image from an airplane at 43,000 feet on Nov.3, 2013 during a rare hybrid annual/total solar eclipse. (Image credit: Ben Cooper/LaunchPhotography.com ) It is a popular misconception that the phenomenon of a total eclipse of the sun is a rare occurrence. How Solar Eclipses Work: When the moon covers up the sun, skywatchers delight in the opportunity to see a rare spectacle. See how solar eclipses occur in this Space.com infographic, (Image credit: Karl Tate, SPACE.com Contributor) Solar eclipse’s shadowy details On the average, the length of the moon’s shadow at new moon is 232,100 miles (373,530 km), and the moon’s distance to the Earth’s surface is, on average, 234,900 miles (378,030 km).
- This means that when the moon passes directly in front of the sun, it the lunar disk will appear slightly smaller than the disk of the sun, and skywatchers will witness what’s known as an annular eclipse, with a dazzling ring of sunlight still visible around the moon’s silhouette.
- Of course total solar eclipses do occur, because the new moon’s distance can vary between 217,730 miles (350,400 km) and 247,930 miles (399,000 km) from the Earth’s surface, on account of the moon’s elliptical orbit.
So now, let’s return to our original question: How often a total eclipse can be seen from a specific point on the Earth’s surface? The science of prediction Predicting the details of a solar eclipse requires not only a fairly good idea of the motions of the sun and moon, but also an accurate distance to the moon and accurate geographical coordinates.
- Rough determinations of eclipse circumstances became possible after the work of Claudius Ptolemy (around A.D.150), and diagrams of the eclipsed sun have been found in medieval manuscripts and in the first books printed about astronomy.
- Since the distance to the moon varies, the width of the path of totality differs from one eclipse to another.
This width will change even during a single eclipse, because different parts of the Earth lie at different distances from the moon and also because of geometrical effects as the shadow falls at an oblique angle onto the Earth’s surface. In calculating a solar eclipse, one of the first steps is to determine the shadow’s relation to the “fundamental plane,” which passes through the Earth’s center and is perpendicular to the moon-sun line.
- The path of the axis of the shadow across this plane is virtually a straight line.
- It is from this special geometry, that the intersection of the moon’s dark shadow cone with the rotating spheroid of our Earth must be worked out, using lengthy procedures in trigonometry.
- To say the least, these factors can make the calculations quite involved (although today’s high-speed PCs can effortlessly crunch the numbers, making the task much easier).
In their classical textbook “Astronomy” (Boston, 1926), authors H.N. Russell, R.S. Dugan and J.Q. Stewart noted that: “Since the track of a solar eclipse is a very narrow path over the earth’s surface, averaging only 60 or 70 miles in width, we find that in the long run a total eclipse happens at any given station only once in about 360 years.” More recently, Jean Meeus of Belgium, whose special interest is spherical and mathematical astronomy, recalculated this figure statistically on an HP-85 microcomputer and found that the mean frequency for a total eclipse of the sun for any given point on the Earth’s surface is once in 375 years.
- A value that is very close to the figure that Russell, Dugan and Stewart arrived at.
- Related: Amazing Solar Eclipse Photos Without retracing these computations, there is perhaps another way to check the validity of these answers.
- In the table below, is a listing of 25 cities.
- Twenty-three are in North America, plus two others: Honolulu, on the Hawaiian Island of Oahu, and Hamilton, the capital of Bermuda.
Using two computer programs designed to scan through the centuries for eclipses, I first searched for the date of the most recent total solar eclipse that was visible from each city, then searched for the date when the next total eclipse for that city would take place.
But it should first be stressed that the nearly four-century wait is merely a statistical average. Indeed, over a much shorter span of time, the paths of different eclipses can sometimes crisscross over a specific place, so in some cases the wait might not be so long at all. In fact, a 40-mile stretch of the Atlantic coast of Angola, just north of Lobito, experienced a total solar eclipse on June 21, 2001, and was treated to another on Dec.4, 2002, after less than 18 months! On the other hand, as Meeus recently discovered, some spots on the Earth’s surface may not see a total solar eclipse for 36 centuries (” though this must be exceedingly rare,” he notes).
On our list of 25 selected cities, how close would we come to the computed mean-frequency of nearly 400-years between total eclipses? Here is the list: A single asterisk (*) denotes that either the northern or southern limit of the moon’s umbral shadow only grazes a specific city; only part of that metropolitan area will see a total eclipse while the other part sees a partial eclipse. A double asterisk (**) indicates a date when the now-defunct Julian calendar was in effect.
- The average number of years between eclipses turned out to be nearly 534 years.
- Considering our relatively small survey of 25 cities, this is reasonably close to the once-in-almost four-century rule.
- A botched opportunity All of us who enjoy solar eclipses should be indebted to those astronomers who pioneered doing these extensive calculations; otherwise we would not know exactly where to position ourselves for the big event.
Prussian astronomer Friedrich Bessel introduced a group of mathematical formulas in 1824 (now called “Besselian Elements”) that greatly simplified the calculation of the position of the sun, moon and Earth. Related: The World’s 1st Televised Solar Eclipse It is too bad that Bessel’s procedures were not available in the late 18th century, when Samuel Williams, a professor at Harvard, led an expedition to Penobscot Bay, Maine, to observe the total solar eclipse of Oct.27, 1780.
- As it turned out, this eclipse took place during the Revolutionary War and Penobscot Bay lay behind enemy lines.
- Fortunately, the British granted the expedition safe passage, citing the interest of science above political differences.
- And yet in the end, it was all for naught.
- Williams apparently made a fatal error in his computations (or used a poor map) and inadvertently positioned his men at Islesboro — outside the path of totality — likely finding this out with a heavy heart when the waning crescent of sunlight slid completely around the dark edge of the moon and started thickening! WARNING: Never look directly at the sun during an eclipse with a telescope or your unaided eye; severe eye damage can result,
( Scientists use special filters to safely view the sun,) Editor’s Note: If you snap an amazing picture of the July 2, 2019 total solar eclipse (opens in new tab), you can send photos, comments, and your name and location to managing editor Tariq Malik at [email protected],
Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmer’s Almanac and other publications, and he is also an on-camera meteorologist for News 12 Westchester, N.Y. Follow us @Spacedotcom, Facebook and Google+,
Original article on Space.com, Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: [email protected] Joe Rao is Space.com’s skywatching columnist, as well as a veteran meteorologist and eclipse chaser who also serves as an instructor and guest lecturer at New York’s Hayden Planetarium.
- He writes about astronomy for Natural History magazine, the Farmers’ Almanac and other publications.
- Joe is an 8-time Emmy-nominated meteorologist who served the Putnam Valley region of New York for over 21 years.
- You can find him on Twitter and YouTube tracking lunar and solar eclipses, meteor showers and more.
To find out Joe’s latest project, visit him on Twitter.
How often can Earth get solar eclipses?
As we admire the rarity of a total solar eclipse, many questions come to mind that not only occur to us now, but have puzzled eclipse watchers for thousands of years. Here are a few basic questions and their answers, with more on the way as we get closer to the August 21, 2017 event.
- The rods and cones in the human retina are very sensitive to light.
- Even a thin sliver of the sun’s disk covers thousands of these light-sensitive cells.
- Normally during daylight conditions, the iris contracts so that only a small amount of light passes through the lens and then reaches the retina.
- This level of indirect sunlight is perfectly OK and the eye has evolved over millions of years to safely see the daylight world under most circumstances.
The problem is that the sun’s surface is so bright that if you stare at any portion of it, no matter how small, it produces enough light to damage individual retinal cells. It takes a few seconds for this to happen, but afterwards you will see a spot as big as the solar surface you glimpsed when you look away from the sun at some other scenery.
Depending on how long you gazed at the sun and how badly the retinal cells were damaged, this spot will either fade away in time or remain permanent. You should never assume that you can look away quickly enough to avoid eye damage because every person is different in terms of their retinal sensitivity, and you do not want to risk being the one who damages their eyes just to try to look at the sun.
If you want to see what the sun looks like, use a properly-equipped telescope. Or why not just go online and view thousands of pictures taken of the sun by telescopes and NASA spacecraft! There is a misunderstanding being circulated that during a total solar eclipse when the moon has fully blocked the light from the sun, that there are still harmful ‘rays’ that can injure your eyes.
- This is completely false.
- When the bright photosphere of the sun is completely covered, only the faint light from the corona is visible, and this radiation is too weak to have any harmful effects on the human retina.
- The misunderstanding comes about because of using the general term ‘solar eclipse’ to describe both the total phase when the sun disk is completely blocked, and the minutes before and after totality when there is still some of the sun’s disk visible.
It is harmful to view even a sliver of the sun disk because of its intensity, and so to simply say that you should not view a solar eclipse is rather inaccurate. There is no evidence that eclipses have any physical effect on humans. However, eclipses have always been capable of producing profound psychological effects.
- For millennia, solar eclipses have been interpreted as portents of doom by virtually every known civilization.
- These have stimulated responses that run the gamut from human sacrifices to feelings of awe and bewilderment.
- Although there are no direct physical effects involving known forces, the consequences of the induced human psychological states have indeed led to physical effects.
Solar retinopathy is a result of too much ultraviolet light flooding the retina. In extreme cases this can cause blindness, but is so painful that it is rare for someone to be able to stare at the sun for that long. Typically, eye damage from staring at the sun results in blurred vision, dark or yellow spots, pain in bright light or loss of vision in the center of the eye (the fovea).
Permanent damage to the retina has been shown to occur in ~100 seconds, but the exact time before damage occurs will vary with the intensity of the sun on a particular day and with how much the viewer’s pupil is dilated from decongestants and other drugs they may be taking. Even when 99% of the Sun’s surface (the photosphere) is obscured during the partial phases of a solar eclipse, the remaining crescent Sun is still intense enough to cause a retinal burn.
Note, there are no pain receptors in the retina so your retina can be damaged even before you realize it, and by then it is too late to save your vision! Many people will obtain eclipse viewing glasses. To date three manufacturers have certified that their eclipse glasses and hand-held solar viewers meet the ISO 12312-2 international standard for such products: Rainbow Symphony, American Paper Optics, and Thousand Oaks Optical.
These companies may be found online and the glasses ordered, but you really need to order your glasses many months in advance because of the anticipated huge audience that could number in the hundreds of millions. Also, NASA is partnering with GOOGLE and making arrangements to distribute viewing glasses to many institutions and groups along the path of totality.
If you are a photographer or amateur astronomer, you will want professional-grade solar filters to cover your binoculars, telescope or camera. Companies like Thousand Oaks Optical and others you can find by using the keyword ‘Solar filters’ have these filters for sale, but again due to the large number of likely customers along the path of totality, you need to order your filter many months in advance.
Do not wait until June, 2017 to get your filter. You will also need some time to learn how to use the filter with your optical system, and if you are photographing the eclipse, take lots of test shots to get the right solar disk size and sharpness. Actually, although filters and glasses do safely block the intense sunlight that is known to damage retinas, the infrared ‘heat’ from the sun can also make viewing uncomfortable as it literally warms the eye.
This is why staring at the sun for minutes at a time even with proper filters can still over-heat the tissues and fluids in the eye, and the consequences of this heating can be dangerous as well. To avoid this problem before totality takes place, try not to use your filters without frequently looking-away to cool your eyes.
During totality, there is no adverse heating of the eyeball since the solar disk is not visible. Absolutely not! Everyone needs to be reminded that eyes never evolved on Earth to look at the sun without suffering severe damage. We have many built-in reflexes to prevent this. There are no higher organisms on this planet that can do so and not run an enormous risk of being blinded.
Most of the time, astronomers are anxious for you to look at the sky and deeply enjoy the sights that you see. There is never a disclaimer that this is dangerous. The ONLY exception is in viewing solar eclipses. It is an inherently dangerous activity that you have to do very carefully in order not to suffer eye damage. Eclipses occur due to the special coincidence of the moon and the Sun being the same angular size. The Sun is 400 times wider than the moon, but it is also 400 times farther away, so they coincidentally appear to be the same size in our sky. This is what allows us the phenomenal beauty of the total solar eclipse.
- Note: You can give the audience the experience of the change in apparent size of an object close by and the same object farther away.
- They can use their hands to measure angular size.) Because the geometry required for a total solar eclipse has nothing to do with local noon.
- It has to do with when the lunar shadow sweeps across your location during the time when the Sun is above the horizon.
Even so, it is certainly possible for the Sun to be in full eclipse before it rises at your particular location. Eclipses only occur if the Moon is located within 0.5 degrees of the plane of the ecliptic, on a line that passes through the center of the Sun and the Earth.
The Moon travels along an orbit that is inclined by 5 degrees to the ecliptic plane, so there are only two opportunities each month when it passes through the plane of the ecliptic. These points are called the ascending and descending nodes. Eclipses of the Sun only occur if new moon occurs when the Moon is near of one of these nodes.
A similar argument explains why lunar eclipses do not occur every full moon at the node opposite the Sun from the Earth. King Henry I of England, the son of William the Conqueror, died in 1133 CE. This event coincided with a total solar eclipse that lasted over four minutes on August 2,
- Historian William of Malmesbury recounts this “hideous darkness agitated the hearts of men”.
- After King Henry’s death, a struggle for the throne threw the kingdom into chaos and civil war.
- Historians and astronomers believe that the legendary eclipse that two Chinese astrologers Hsi and Ho failed to forecast occurred on October 22, 2134 B.C.E, making it the oldest solar eclipse ever recorded in human history.
The Babylonian eclipse on May 3, 1375 BCE is the oldest successfully predicted and recorded in the western world, and there is evidence that the Babylonians knew about the Saros Cycle (18 years 11 days) and could use it to predict the approximate years of eclipses.
- Other than watch it with your family and friends, you may want to create a time capsule, which you would open on April 8, 2024 when the next total solar eclipse occurs over the continental United States.
- You might want to write a letter to your older self and describe what you think you might be doing in 2024, or include some of your favorite items, or a copy of your daily newspaper.
Nearly all public schools will not be in session, so there will be few formal education events involving your students. However, before the current 2016-2017 school year ends, you should check with your science teachers to see if they might have some ideas for summer projects involving the eclipse.
- For educators, it is highly recommended that you alert your students to this event when school closes in May-June, and equip your students with an Eclipse Project along with your planned summer work activities.
- This eclipse will occur in the week before school begins in 2017-2018 and will be an excellent talking point to start your school year in many subjects such as art, English and of course science and math.
The only requirement for a total solar eclipse is that the angular size of the sun has to match the angular size of some other object that passes in front of it. When the disk of the object is smaller than the sun, this is called a transit. It is also called an eclipse when the disk of the object is much larger than the sun, but in general this would not allow the corona to be viewed, which is how we define total solar eclipses viewed from Earth.
- When humans were rooted to the surface of Earth, this was only the case for the moon as the eclipsing object.
- But there are many known moons and asteroids across our solar system, and from a suitable vantage point near any of them, we can find a distance where again the angular size of the object matches that of the sun to form a total solar eclipse.
There are so many different vantage points to choose from that each case has to be specified. For example, eclipses need not be observed from the surfaces of a planet. In fact, Venus and the outer planets have inaccessible surfaces. Instead, we might consider standing on the surface of a planetary moon and waiting for another moon to pass in front of the sun.
- Given the myriad of planetary moon orbits, finding those instances where the angular sizes match is a significant computational challenge.
- Jupiter frequently passes across the sun as viewed from its moons, but its diameter is huge compared to the sun.
- There are 5 satellites capable of completely occulting the Sun: Amalthea, Io, Europa, Ganymede and Callisto.
All of the others are too small or too distant to be able to completely occult the Sun, so can only transit the Sun. UT or “Universal Time” is a single time standard that applies to all locations on Earth as opposed to your local time which will vary depending on your location (longitude).
For all practical purposes, UT is equivalent to GMT (Greenwich Mean Time) which establishes a line of longitude that passes through Greenwich England (called the Prime Meridian) as the standard from which all other times are measured and UTC (Coordinated Universal Time) which is based on International Atomic Time (time measured very precisely as vibrations of a cesium atom).
The following chart may be used to convert UT to your US time zone during the eclipse. Example: 18:23 UT = 12:23pm MDT The totality only lasts a few very brief minutes and it may be the only such event you ever get to see in your life, so please make sure that you are not so distracted with projects that you miss the event! That said, many people try to photograph the eclipse, which requires lots of pre-planning before the event and sometimes involves specialized equipment.
- Other simple projects can involve measuring temperature, daylight and animal behavior changes in your immediate area.
- These supplementary activities are simple to perform and require a minimum of distraction from your personal enjoyment of the event! You will need to purchase a solar filter that will reduce the brightness of the sun so that the light intensity does not destroy your camera.
If you ONLY take a photo at the moment of totality, you will not need this filter, and will be rewarded by being able to photograph the faint corona, which will not be visible if you have the filter in place. Most digital cameras with telephoto lenses of 100 mm or larger will show a disk for the eclipse that will show some detail.
As a trial, photograph the full moon at night. It will be the same diameter as the total eclipse, so you can practice on the moon first to get the right telephoto lens combination. There are many places on the internet where you can get detailed information such as Mr. Eclipse http://www.mreclipse.com/SEphoto/SEphoto.html It has been reported during many eclipses that many different animals are startled by totality and change their behavior thinking that twilight has arrived.
You can explore this yourself with your own pets, or by watching local wildlife, especially birds. These are among the most ephemeral phenomena that observers see during the few minutes before and after a total solar eclipse. They appear as a multitude of faint rapidly moving bands that can be seen by placing a white sheet of paper several feet square on the ground.
They look like ripples of sunshine at the bottom of a swimming pool, and their visibility varies from eclipse to eclipse.19th century observers interpreted them as interference fringes caused by some kind of diffraction phenomenon. The Sun, however, is hardly a “point source” and the patterns are more random than you might expect from diffraction effects.
The simplest explanation is that they arise from atmospheric turbulence. When light rays pass through eddies in the atmosphere, they are refracted. Unresolved distant sources simply “twinkle,” but for nearby large objects, the incoming light can be split into interfering bundles that recombine on the ground to give mottled patterns of light and dark bands, or portions of bands.
Near totality, the image of the Sun is only a thin crescent a few arc seconds wide, which is about the same size as the atmospheric eddies as seen from the ground. Bands are produced because the Sun’s image is longer in one direction than another. The bands move, not at the rate you would expect for the eclipse, but at a speed determined by the motion of the atmospheric eddies.
It would probably be equal to the typical daytime minus nighttime temperature difference at that time of year and location on the Earth. It would be modified a bit by the fact that it only lasts a few minutes, which means the environment would not have had much time to thermally respond to its lowest temperature, so it would probably only be 3/4 or 1/2 the maximum day-night temperature difference.
- Because the patch of the shadow travels faster than the speed of sound, weather systems will only be affected very locally directly under the instantaneous footprint of the eclipse.
- The main effect is in the “radiant heating” component which goes away suddenly at the moment of eclipse and produces a very fast temperature decrease.
If the wind is blowing, your body probably exaggerates, by evaporative cooling, how large the actual temperature swing actually is. The short answer is a definite ‘yes!’, but of course you have to be careful that you minimize glimpsing the bright sun with your eyes without the benefit of a proper filter.
As for your camera, there is no valid reason why you would want to point your smartphone camera at the brilliant, un-eclipsed sun without putting a filter over the lens. During totality, you do not need the filter, of course! Unless you have a telephoto lens for your smartphone, you will only be able to take unmagnified images of the eclipse in your sky.
These photos can be very exciting because the field-of-view is large enough that you can compose the shot with your friends and local scenery in the shot, at the same time a recognizable, eclipsed sun during totality hangs dramatically in the darkened sky.
- You will easily be able to capture with most smartphone cameras the darkened disk of the moon surrounded by a clearly recognizable bright solar corona.
- Many examples of these kinds of wide-angle shots can be found on the Internet.
- Of course, if you use the camera’s digital zoom, you will see a pixelized, enlarged image that will not show much actual detail in the corona.
To get around this, you need a telephoto lens for your smartphone. There are many styles of telephoto lenses for smartphones. Avoid the ‘clip on’ lenses because they constantly slip and have to be precisely lined up on the camera lens to work. They are often of low optical quality.
The best lenses are rated as 12x and above, and come with their own smartphone mounting bracket. At these magnifications, a tripod is essential because of camera jitter. A decent 12x lens and tripod adapter will cost you about $30.00, but you can also use this system for great ‘close up’ shots in sport and nature settings too! The telephoto lens will give you enough magnification that you will clearly see some of the details in the bright corona.
You should test your system by taking night-time photos of the moon so you understand how large and detailed the moon will appear in your shot. The sun/mon during eclipse are equal-sized so this is a good way to compose your eclipse shots too. Also experiment with the settings on your camera using a downloadable app like Camera+ or NightCap Pro, which allow you more flexibility in setting up the exposure, f/stop and other factors.
- For more information on eclipse photography with smartphones, read the project details found at our Citizen Explorers page.
- Above all, don’t forget to put your smartphone down and enjoy the eclipse with your own eyes! Wellno.
- As you get close to totality, you should be able to notice a power drop in the output of your panels, which will reach a minimum when the sun is in full eclipse, and then your power levels will recover as the moon moves away from the sun.
In fact, this may be a fun science project if you can get in touch with many people in other cities that also have solar panels they can monitor. Just like some folks will be watching for temperature changes and the dimming of sunlight during the eclipse, you can measure the drop in solar power reaching Earth’s surface as a companion observation! Go for it!! The next total solar eclipse visible from the United States occurs on August 21, 2017. The track goes from Oregon at its start, and exits on the east coast near South Carolina. After that, the next one visible from the Lower-48 will be on April 8, 2024 which will track northeast from Texas to Maine and cross the path of the 2017 eclipse near Carbondale, Illinois.
- Since 1503, there have been 15 total solar eclipse paths that have crossed the path of the August 2017 eclipse.
- Calculations show that it will take about 1000 years for every geographic location in the Lower-48 to be able to view a total solar eclipse.
- The last total solar eclipse viewed from contiguous United States was on Feb.26, 1979 whose path passed through the northwestern U.S.
states of Washington, Oregon, Idaho, Montana, North Dakota, and Canadian provinces of Saskatchewan, Manitoba, Ontario and Quebec. After the August 2017 total solar eclipse, the next annular solar eclipse that can be seen in the continental United States will be on October 14, 2023 which will be visible from Northern California to Florida.
Following this, we will have a total solar eclipse on April 8, 2024 visible from Texas to Maine. The Babylonians knew how to predict lunar eclipses with some accuracy, but solar eclipses are far more difficult because the ‘footprint’ on the Earth is only a few tens of miles across and requires arc minute positional accuracy and forecasting for any specific locale.
Apparently Thales, c.610 B.C. E, is credited with predicting a solar eclipse from knowledge of a previous eclipse and using the Saros cycle. He predicted the year, but not the month and the day. It wasn’t until Ptolemy’s time that solar eclipse forecasting became more accurate.
Appalachian Trail (TN, SC, GA) Blue Ridge Parkway (TN, NC) Craters of the Moon (ID) John Day Fossil Beds (OR) Grand Teton National Park (WY) Fort Laramie National Historic Site (WY) Scott’s Bluff NM (NE) Agate Fossil Beds National Monument (NE) Homestead National Monument of America (NE) Harry S Truman National Historic Site (MO) Ulysses S. Grant National Historic Site (MO) Stones River (TN) Obed WSR (TN) Great Smoky Mountains National Park (TN) Ninety Six National Historic Site (SC) Congaree National Park (SC) Charles Pinckney National Historic Site (SC) Fort Sumter National Monument (SC) Mammoth Cave National Park (KY) Lewis & Clark National Historic Trail (Omaha) Fort Donelson National Battlefield (TN) Manhattan Project National Historic Park (TN)
Including Alaska, Hawaii and the Lower-48, here are the total solar eclipses visible during this period and what was going on at those times: July 11, 1991 – (Hawaii) Most popular song: ‘I Do it for You’ by Bryan Adams was the top song. Popular movie.’Terminator 2 ‘.
Price of gasoline: $1.14. Stock Market: 3000. President in office: George H.W. Bush. Major current event: Nigeria Airways DC-8 crashes at Jeddah, Saudi Arabia, killing all 261 passengers and crew on board. Major scientific event this year: First website goes online at CERN(August); Dinosaur extinction attributed to asteroid impact in Yucatan.
July 10, 1972 – (Alaska) Most popular song: “Lean on Me” by Bill Withers was the top song. Popular movie. ‘Deliverance’. Price of gasoline: $1.59. Stock Market: 930. President in office: Richard Nixon. Major current event: Chess match between world champion Boris Spassky of the Soviet Union, and United States champion Bobby Fischer, in Iceland.
- Major scientific event this year: The Soviet space probe Venera 8 landed on Venus in July.
- Mariner 9 sends pictures from Mars in February.
- Apollo 16 launched in April.
- First scientific hand-held calculator on sale.
- February 26, 1979 – (Lower-48) Most popular song: Le Freak by Chic was the top song.
- Popular movie The Deer Hunter.
Price of gasoline: $0.86. Stock Market: 821. President in office: Jimmy Carter. Major current event: Ayatolla Khomaini seizes power in Iran. Major scientific event this year: WHO certifies global eradication of smallpox. March 7, 1970 – (Lower-48) Most popular song: Bridge over Troubled Water by Simon and Garfunkel.
Popular movie – Patton. Price of gasoline: $0.36. Stock Market: 784. President in office: Richard Nixon. Major current event: First Boeing 747 flies. US lowers voting age from 21 to 18. Major scientific event this year: Venera 7 becomes first spacecraft to reach surface of Venus. July 20, 1963 – (Alaska, Maine) Most popular song: Surf City by Jan and Dean.
Popular movie – Cleopatra. Price of gasoline: $0.30. Stock Market: 694. President in office: John Kennedy. Major current event: ZIP codes introduced in the US. Major scientific event this year: British geophysicists publish proof of seafloor spreading on the Atlantic Ocean floor.
According to a map in which the tracks of all total solar eclipses from 1000 to 2000 BCE have been overlain, there are two such areas; one in north eastern Colorado centered on Fort Morgan, and one in Nebraska centered near Lewellen, that have not seen a total solar eclipse in over 1000 years. Each area is about 50 km across.
There will literally be thousands of different venues to choose from across the continental United States. Some will offer lectures about eclipses, safe locations for viewing, proper viewing glasses, and many may host a variety of podcasts and other social media opportunities.
- Some of these will be featured on the NASA Eclipse 2017 website and/or on our Eclipse Megacast, which will be live-streaming webcast.
- Because most locations will not have schools in session, your local museum will likely have a schedule of planned events to choose from.
- Also check out your local amateur astronomer club, which will be especially active and will likely offer safe telescopic observing of the event.
Total solar eclipses have, indeed, been a popular theme. We have a short list of these examples on our webpage at http://eclipse2017.nasa.gov/eclipses-and-music The most famous example is Carly Simon’s ‘You’re so Vain ‘ where she sings ‘. you flew your Lear jet up to Nova Scotia To see a total eclipse of the sun’.
Her lyric refers to the March 7, 1970 total solar eclipse, and this is the only known recorded song that mentions a specific eclipse. This will make future historians very happy if they try to date when the song was written if no other records exist. This is kind of like what archaeologists do with Babylonian cuneiform eclipse records today.
By the way, there was a later ‘Nova Scotia’ eclipse on July 10, 1972, but Simon’s song came out in 1971. Time travel had not been invented yet. This is easyjust show up! Find a location in your area where there are likely to me many people, or contact your local museum and get on their list of ‘eclipse helpers’.
If you have a telescope with the right filters, bring it with you and set it up so that people can view the eclipse before totality starts. Also, if you have one of those special ‘Hydrogen-alpha’ filters you can use it to show people what the surface of the sun looks like,There may still be a few sunspots to view this late in the current sunspot cycle.
Be prepared to answer all kinds of unusual questions, so make sure you have done your homework on the basic details about the sun, its corona and other features such as its size relative to Earth and other similar things. The only reason that total solar eclipses only last a few minutes for a ground-based observer is that that is about how much time it takes the lunar shadow, traveling at over 2,000 km/hr to pass you’re your geographic location.
But what would happen if you could fly along the path of totality at the same speed as the lunar shadow? Well, you would see a continuous eclipse for as long as the shadow touches Earth, which can be several hours from start to finish. Astronomers figured this out long ago, but had to wait for the invention and deployment of non-military supersonic jets to carry out such a chase.
The scientific benefit is enormous because now you can study the sun’s corona for much longer than the 2-5 minutes usually allowed. On June 30, 1973, Concorde 001 intercepted the path of a solar eclipse over North Africa. Flying at Mach 2.05 the aircraft provided seven observers from France, Britain and the United States with 74 min of totality bounded by extended second (7 min) and third (12 min) contacts.
- The former permitted searches for time variations of much longer period than previously possible and the latter provided an opportunity for chromospheric observations of improved height resolution.
- The altitude, which varied between 16,200 and 17,700 m, freed the observations from the usual weather problems, and greatly reduced atmospheric absorption and sky noise in regions of the infrared.
The solar eclipse of March 20, 2015, was the first eclipse for which a significant impact on the power system occurred. The continental Europe and Great Britain generated about 90 Gigawatts of solar power and production was estimated to have decreased by up to 34 GW compared to a clear sky day.
- Also for wind farms there is a potentially smaller effect because as temperatures decrease during the eclipse, winds also slacken a bit, and this could cause wind turbines to rotate less vigorously.
- Of course if you are on the path of totality, you will lose nearly 100% of your normal daylight illumination when totality happens.
It will seem like late-twilight with a narrow ring of daylight encircling your horizon. If you are only able to watch the partial eclipse, your experience will be quite different. Unless the sun is at least 75% covered by the moon, you may not even notice much illumination change at all unless you are aware the eclipse is happening.
It is only by the time the eclipse reaches about 90% coverage that you will start to notice a landscape dimming, and by about 95% you will definitely be aware of something happening to the sunlight even if you did not know there was an eclipse at that moment. The details, of course, will change depending on how aware you are of the exact timing of the event, and even your emotional state and its impact on your sensory acuity.
One thing you may notice once the eclipse reaches about 90% is that the shadows on the ground will start to seem less sharp as the light source (the illuminated sun) becomes smaller. Also look for crescent-shaped shadows cast by light passing through gaps in the leaves on trees. There are two orbit locations where eclipses can occur. These are the points in the lunar orbit that intersect the ecliptic plane where the Sun moves in the sky. Called the ascending node and the descending node, eclipses can occur at either node. The Moon must be in the full moon phase as it passes the node in order for a lunar eclipse to occur.
Similarly, solar eclipses only occur during new moon when this phase occurs at either node. Because the Moon moves to the east in its orbit at about 3,400 km/hour. Earth rotates to the east at 1,670 km/hr at the equator, so the lunar shadow moves to the east at 3,400 – 1,670 = 1,730 km/hr near the equator.
You cannot keep up with the shadow of the eclipse unless you traveled at Mach 1.5. Astronomers first have to work out the geometry and mechanics of how the Earth and Moon orbit the Sun under the influences of the gravitational fields of these three bodies.
- From Newton’s laws of motion, they mathematically work out the motions of these bodies in three-dimensional space, taking into account the fact that these bodies have finite size and are not perfect spheres, and that the Earth and Moon are not homogeneous bodies.
- From careful observation, they then feed into these complex equations the current positions and speeds of the Earth and Moon, and then program the computer to “integrate” these equations forward or backward in time to construct ephemerides of the relative positions of the Moon and Sun as seen from the vantage point of the Earth.
Eclipses are specific configurations of these bodies that can be identified by the computer. Current eclipse forecasts are accurate to less than a minute in time over a span of hundreds of years. The orbit of the moon is not stable. Because of tidal friction, the orbit of the Moon is steadily growing larger, so that the angular size of the moon from the Earth is shrinking.
- The moon’s orbit is increasing by about 3.8 cm (1.5 inches) per year.
- When the moon’s mean distance from Earth has increased an additional 14,600 miles, it will be too far away to completely cover the sun.
- This is true even at perigee when its disk will be smaller than the sun’s disk even when the sun is farthest from Earth at aphelion.
At the current rate that the moon’s orbit is increasing, it will take over 600 million years for the last total solar eclipse to occur. A complicating factor is that the size of the sun itself will grow slightly during this time as it evolves as a star, which will act to make the time of “no more total eclipses” a bit sooner than 600 million years.
Solar eclipses are fairly numerous, about 2 to 4 per year, but the area on the ground covered by totality is only about 50 miles wide. In any given location on Earth, a total eclipse happens only once every hundred years or so, though for selected locations they can occur as little as a few years apart.
An example is the August 21, 2017 and April 8, 2024 eclipses, which will be viewed at the same spot near Carbondale, Illinois. Eclipses of the Moon by the Earth’s shadow are actually less numerous than solar eclipses; however, each lunar eclipse is visible from over half the Earth.
- At any given location, you can have up to three lunar eclipses per year, but some years there may be none.
- In any one calendar year, the maximum number of eclipses is four solar and three lunar.
- The positions of the Sun and Moon are known to better than 1 arc second accuracy.
- This means that on the Earth, the location of the track of totality is probably known to about (1.0/206265.0) x 2 x pi x 6400 km = 0.19 kilometers or a few hundred meters at the Earth’s equator.
“Atlas of Historical Eclipse Maps for East Asia 1500BC to 1900 AD” by F.R. Stephenson and M.A. Houlden, (Cambridge University Press) 1986. “Canon of Eclipses” by Theodor Oppolzer, translated by Owen Gingerich in 1962. (Dover Books, New York). “Canon of Solar Eclipses” by Jean Meeus and Hermann Mucke, (Astronomiches Buro, 1983) Vienna Austria, second edition.
We all know that the Ancient Chinese were so fearful of the sun being ‘eaten by a dragon’ that they clanged pots and other noisy things to scare off the dragon and bring back the sun. This tradition apparently goes back a very long time, and may have been started several thousand years ago. We know that Ancient Chinese astrologers were carefully searching for eclipses as far back as 2100 BCE.
But what of other civilizations such as ancient Egypt and those such as the Incas, Mayas and Aztecs? Amazingly, there are no recorded documents or hieroglyphs that suggest the sudden and unpredicted absence of the sun disks associated with Quetzalcoatl (Inca) or Ra (Egypt) was noteworthy in the archeological record.
- Part of this, in the case of Egypt, may be due to the fact that most of the eclipse tracks for the period from 2,000 BDC to 1000 BCE, for example, passed over extremely low population density areas in Egypt where there would be very few people to notice the 2-5 minute dimming of the sun.
- However, the total solar eclipses of 1883, 1532 and 1337 BCE passed over Cairo, and the eclipses of 1949, 1257 and 1123 BCE passed close to Luxor.
Perhaps there are records somewhere yet to be translated, discovered, or critically analyzed, that mention such unusual solar events, no doubt witnessed by thousands of people each time in these high-population areas. During the last century, the precise timing and track of totality could be used to make ultra-precise measurements of the lunar orbit and improve the mathematical model for the gravitational interactions between earth and the moon.
In 1919, a total solar eclipse was used to test Einstein’s Theory of General Relativity. Studies of the solar corona during totality were also used to examine its structure and changes in time, and to relate the features seen with details on the solar surface. Currently, there have been attempts to detect interplanetary dust falling into the sun by searching for its faint infrared light beyond the corona.
There are also studies of the solar transition region being performed by the glimpses of it provided during totality. Recently, lunar profile data from the NASA LRO mission have been used to predict the exact timing and brilliance of Bailey’s Beads shortly before totality.
So new scientific uses for this spectacular phenomenon are found nearly every year! This is about 7.5 minutes. The longest total solar eclipse from 4000 BCE to 8000 CE, a span of 12,000 years, will occur on July 16, 2186 and will last 7 minutes 29 seconds. Its path sweeps across Colombia, Venezuela and Guyana.
The August 21, 2017 total solar eclipse, by comparison, will last a maximum of 2 minutes 43 seconds. About 70% of eclipses last longer than this. During the 5,000-year period from -1999 to +3000 (2000 BCE to 3000 CE), Earth will experience 11,898 eclipses of the Sun.
The statistical distribution of eclipse types for this interval is as follows: 4,200 partial eclipses, 3,956 annular eclipses, 3,173 total eclipses and 569 hybrid eclipses. That means that, every 1000 years you have 840 partial eclipses, 791 annular eclipses, 635 total eclipses and 114 hybrid eclipses.
That works out to 2-3 eclipses of all kinds each year, and about 2 total solar eclipses every 3 years. Wellmy birthday is November 23. The last total solar eclipse on my birthday was in 2003. The next one is in the year 2337, followed by the years 2356 and 2728, so the intervals are 334 years, 19 years and 372 years.
- So depending on which part of the cycle you are on, you may either wait about 20 years or about 350 years for the next occurrence! Check out the Five Millennium Canon of Eclipses to find the one nearest your birthday.
- It is located at https://eclipse.gsfc.nasa.gov/SEcat5/SEcatalog.html On July 28, 1851 the Royal Prussian Observatory at Königsberg (now Kaliningrad, in Russia) commissioned one of the city’s most skilled daguerreotypists, Johann Julius Friedrich Berkowski, to record a still image of the event.
A Saros Cycle is approximately 6585.3211 days, or 18 years, 11 days, 8 hours in length. One saros period after an eclipse, the Sun, Earth, and Moon return to approximately the same relative geometry, a near straight line, and a nearly identical eclipse will occur.
The Moon will have the same phase and be at the same node and the same distance from the Earth. In addition, because the saros is close to 18 years in length (about 11 days longer), Earth will be nearly the same distance from the sun, and tilted to it in nearly the same orientation (same season). Given the date of an eclipse, one saros later a nearly identical eclipse can be predicted.
Each total solar eclipse track looks similar to the previous one, but is shifted by 120 degrees westward. The August 21, 2017 total solar eclipse is part of the Saros 145 series. The previous total solar eclipse in this series occurred on August 11, 1999.
- The next one will be on September 2, 2035.
- The first cycle in this series occurred on January 4, 1639, and the last one will be on April 17, 3009.
- Of course the most spectacular use has been to study the faint corona of the sun, which can be observed by spacecraft such as the Solar and Heliospheric Observatory (SOHO) by making artificial eclipses, but ground-based telescopes and photography have also made many historical contributions to understanding the shape, structure and extent of the corona.
Also, total solar eclipses have been invaluable in improving our understanding of the lunar orbit. Whether a total solar eclipse occurs at a specific location and time on the surface of Earth depends on the lunar orbit, the motion of the moon along the orbit, the earth-moon distance and other factors.
Sophisticated physics-based computer models have been used for over a century to make accurate predictions of each eclipse to the second, and to the nearest mile on Earth. The best way to do this is to look at historical sightings of total solar eclipses from centuries or even millennia in the past. These sightings are often made by observers at specific geographic locations and who indicate the time of the eclipse from that location.
These distant-in-time observations can be calculated by the modern eclipse models and compared with the historical sighting, then the models can be adjusted by improving the parameters of the physics calculation until agreement is reached. This process sometimes results in new ‘science’ related to the shape of the moon, or gravitational perturbations in the lunar orbit that can take centuries to build up to measurable effects.
For example, in 1989 an astronomical event recorded on a clay tablet found in 1948 among the ruins of the ancient city of Ugarit, Syria, was identified as a description of a total solar eclipse that occurred on 3 May 1375 BCE. The information was used to provide a reference point to establish the long-term evolution of angular momentum in the Earth-Moon system Apart from being a wonderful word to use in the game of Scrabble, this astronomical term is an event in which one astronomical object is lined-up with another.
This leads to the pithy aphorism: all eclipses are syzygys but not all syzygys are eclipses. For example, Full moon and New Moon are syzygys involving the lining up of the Sun, Earth and Moon, therefore, lunar and solar eclipses are syzygys. When a planetary moon passes across the face of another body but does not eclipse it, this is called a transit.
- From Earth, the small disks of Venus and Mercury can be seen passing across the face of the sun during transits of Venus and Mercury.
- These also involve the straight-line alignment of the Sun, Earth and each planet.
- On June 3, 2014, the Curiosity rover on Mars observed the planet Mercury transiting the sun, marking the first time a planetary transit has been observed from a celestial body besides Earth.
Previously, the Curiosity rover has captured images of the Martian moons Phobos and Deimos transiting the sun. The sun will be well-way from its maximum sunspot numbers during this cycle (Number 24) which peaked in 2013 with about 130 spots during the peak month.
- By August, 2017 the average number should be about 30 per month.
- Sunspot minimum will occur sometime in ca 2020 if the current trends continue.
- What this means is that there may be fewer large sunspots, and the ones you see before eclipse will be concentrated near the equatorial zone of the sun.
- As we get closer to the time of the eclipse, make sure you check with the NASA Solar Dynamics Observatory (SDO) page at http://sdo.gsfc.nasa.gov/data/ to see what the sun looks like a day or so before the eclipse.
That way you can identify any large ‘active regions’ before you try to search for them at your telescope! Yes. Totality currently can never last more than 7 min 32 s. This value changes over the millennia and is currently decreasing. By the 8th millennium, the longest theoretically possible total eclipse will be less than 7 min 2 s.
The last transits of Venus occurred on June 8, 2004 and June 5, 2012, with the next pair predicted for December 10, 2117 and December 8, 2125. Transits of Mercury are much more common, with the most recent one occurring on May 9, 2016 and the next one on November 11, 2019. It is not unreasonable to ask when we might expect such transits to occur during the time of a total solar eclipse.
The next anticipated simultaneous occurrence of a solar eclipse and a transit of Mercury will be on July 5, 6757, and a solar eclipse and a transit of Venus is expected on April 5, 15232. No. If the corona of the sun were not so bright, you would see the moon very faintly illuminated by earthshine.
Our Earth is fully illuminated during the eclipse and it reflects quite a bit of light into space. Some of this lands on the lunar surface and provides a secondary source of illumination. But because the sun’s corona is so bright, your eyes will not see this earthshine effect. Because 223 synodic months is not identical to 239 anomalistic months or 242 draconic months, The 18-year saros periods do not endlessly repeat.
Each series begins with the Moon’s shadow crossing Earth near the north or south pole, and subsequent events progress toward the other pole until the Moon’s shadow misses Earth and the series ends. A full series from start to finish lasts about 1,300 years.
- The August 21, 2017 eclipse is part of Saros Series 145 that includes 77 eclipses of which the August eclipse is number 22.
- All eclipses in this series occur at the ascending node of the lunar orbit.
- The series began with the partial solar eclipse of January 4, 1639 visible at the North Pole.
- The series will end with the partial solar eclipse of April 17, 3009 visible from the South Pole.
The length of this series is 1,370 years. By the way, the total solar eclipse of August 21 is preceded two weeks earlier by a partial lunar eclipse on August 7, 2017, which occurs during the same eclipse season when the sun is nearest this node. Amazingly we may actually have a plausible answer to this question! For an eclipse to occur, you first need a star, and then a planet with a moon for which the moon will provide the eclipse.
- At 1 billion years after the Big Bang, the oldest known planet PSR B1620-26 b had already formed.
- Located in the globular cluster Messier-4 about 12,400 light-years from Earth, it bears the unofficial nicknames “Methuselah” and “The Genesis Planet” because of its extreme age: about 12.8 billion years.
The planet is in orbit around the two very old stars: A dense white dwarf star and a neutron star. The planet has a mass of 2.5 times that of Jupiter, and orbits at a distance a little greater than the distance between Uranus and our own Sun. Each orbit of the planet takes about 100 years.
Like the large planets in our solar system, it is not unreasonable to assume that Methuselah may also have one or more moons, and that one may provide an eclipse of the white dwarf star from the surface of Methuselah, or that from the vantage point of one of its moons, another moon may provide such an eclipse or transit! Wellnot exactly! An eclipse requires that the sun or star be fully covered by the disk of a planet as the planet passes between the star and an observer on Earth.
From basic geometry, the amount of starlight dimming depends on the ratio of the circular area of the planet to the circular area of the star. For an eclipse, 100% of the star’s light is dimmed. This requires that the planet have the same diameter as the star, which is physically impossible.
- However, when the planet’s diameter is much smaller than the star, astronomers call this a transit, and this is one of many methods that are actually used to detect planets orbiting distant stars.
- For example, a Jupiter-sized planet has a diameter of 143,000 km while a sun-like star has a diameter of 1.4 million km, so the ratio of their areas is 1/100.
As this exoplanet transits the disk of its star as viewed from Earth, the brightness of the star will dim by 1%. Since the 1990’s, astronomers have detected over 3,600 exoplanets orbiting 2,700 stars. Of these, NASA’s Kepler observatory has detected over 2,300 of the confirmed exoplanets using the transit method.
- Another exciting aspect of exoplanet transit detections is that the star’s light passes through the atmosphere of the exoplanet on its way to Earth.
- By using an instrument called a spectroscope, astronomers can examine the way the atmosphere absorbs the star’s light to detect the composition of the atmosphere.
Dozens of exoplanets have been studied in this way so far. Most reveal signs of carbon dioxide, water vapor and methane. If oxygen is ever discovered, this will be an important sign that the planet harbors a biosphere of some kind! The moon’s limb is not perfectly smooth because of the mountain ranges and canyons that pepper the moon’s circumference as viewed from Earth.
- Shortly before the moon fully blocks the disk of the sun during a total solar eclipse, flashes of light can often be seen around the circumference of the moon’s blackened disk.
- These are caused by sunlight passing through the canyons around the limb of the moon.
- The namesake for these ‘diamond ring’ flashes is Francis Baily; a prominent English astronomer and four-time president of the Royal Astronomical Society.
His vivid description of the phenomenon (following an eclipse on May 15, 1836) caused it to be associated with his name in 1836, but he was not the first historically-named person to discover this phenomenon. More than a century earlier, the famous English astronomer Sir Edmond Halley (discoverer of Halley’s Comet) described this spectacular phenomenon and also gave a correct explanation for it during an eclipse in 1715: “About two Minutes before the Total Immersion, the remaining part of the Sun was reduced to a very fine Horn, whose Extremeties seemed to lose their Acuteness, and to become round like Stars,
Which Appearance could proceed from no other Cause but the Inequalities of the Moon’s Surface, there being some elevated parts thereof near the Moon’s Southern Pole, by whose Interposition part of that exceedingly fine Filament of Light was intercepted.” Thanks to the results from the NASA Lunar Reconnaissance Orbiter, which measured details across the entire moon to 2-meter accuracy, we can now predict exactly when and where these brilliant flashes of light will appear as a total solar eclipse takes place, because now we know where and how deep the lunar limb canyons will be.
Still, despite our abilities to predict it, this lovely effect and its diamond ring-like character will continue to mesmerize observers for all times to come! The first thing to realize is that the moon is in its ‘new’ phase, so whatever gravitational effects you might expect during a total solar eclipse also happen any time there is a New Moon, which happens every 28 days.
- Starting as an observer on the ground, you are under the gravitational influence of Earth, the moon and the sun.
- At the time of the August 21, 2017 eclipse, Earth will be 151.4 million kilometers from the sun, and the moon will be located 365,649 km from the surface of Earth.
- Using Newton’s Law of Gravity, we can calculate the force of the sun, moon and Earth on an 80 kg person.
Earth accounts for 784.1 Newtons of force (176.42 pounds), the moon provides 0.0029 Newtons (0.01 ounces) and the sun provides 0.4633 Newtons (1.6 ounces). But because our Earth rotates, this also provides an ‘anti-gravity’ centrifugal force we can also calculate.
So if we add the forces with their correct directions we get a total gravitational force of 784.1 – 0.0029 – 0.4633 = 783.634 Newtons or 176.317 pounds. So, you will be about 1.7 ounces lighter! The gravitational effect of the sun and moon being on the same side of Earth during New Moon is actually far more dramatic when you look at what happens to our entire planet.
First, the gravitational ‘tidal’ force of the moon and sun cause a body tide in the solid rock of Earth. If you are on the same line defined by the centers of Earth, the sun and moon, Earth’s crust actually bulges upwards by about 40 millimeters across a thousand-kilometer area on Earth’s surface.
What eclipse happens every 300 years?
Skip to the Questions Perhaps the most spectacular astronomical events that one can observe without a telescope, lunar and solar eclipses were considered omens of great fortune or complete disaster in ancient times. We now know that the occurrence of eclipses is a consequence of the orbits of the Earth and Moon with respect to the Sun. Credit: Luc Viatour / www.Lucnix.be Total solar eclipse 1999 in France. A total solar eclipse occurs where the moon completely covers the sun’s disk, as seen in this 1999 solar eclipse. Solar prominences can be seen along the limb (in red) as well as extensive coronal filaments.
- The Earth orbits the Sun once a year, and the Moon orbits the Earth once a month; it turns out that the planes of the Moon’s and Earth’s orbits are almost, but not quite, aligned (the offset is about 5 degrees).
- This means that every once in awhile (a few times a year), the Moon passes through the Earth’s shadow at night, blocking our view of the Moon: we call this a lunar eclipse.
Similarly, the Moon can come between the Sun and the Earth during the day, temporarily blocking the Sun from view: these events are called solar eclipses. Thus contrary to the ancients’ beliefs, these alignments are not conjured up by the divine but are predictable consequences of the Moon’s and Earth’s orbits in the solar system.
- It is quite fortuitous, however, that despite their vastly different physical extents, the Sun and the Moon appear to be about the same size in the sky (the Sun is much, much bigger than the Moon, but also much farther away from the Earth).
- So, when a solar or lunar eclipse occurs, it is possible for one object to completely obscure the other from view: this is called a total eclipse.
It is more common, however, that only part of the Moon or Sun is obscured, in which case we call it a partial eclipse. Credit: Randall J Scholten Total lunar eclipse. A series of images of the August 28, 2007 lunar eclipse taken from the Oregon Coast by Randall J Scholten using a Nikon D200 and 200mm zoom lens. Though a total solar eclipse may be seen more than once a year on Earth, from a given spot on the planet these events are almost as rare as they are spectacular.
- The relative motions of the Earth and the Moon cause solar eclipses to be visible only within a strip of a few degrees in latitude, and total obscuration lasts no more than about seven minutes.
- Thus, at any single location on Earth, a total solar eclipse occurs only once every 300 years or so.
- Because the shadow cast by the Earth is quite a bit larger than the Moon, lunar eclipses are more common than solar eclipses, and totality can last for about an hour.
Nonetheless, the beauty of such events entices both professional and amateur astronomers alike to chase them all around the globe!
How rare is a solar eclipse?
Final totality – Total solar eclipses are seen on Earth because of a fortuitous combination of circumstances. Even on Earth, the diversity of eclipses familiar to people today is a temporary (on a geological time scale) phenomenon. Hundreds of millions of years in the past, the Moon was closer to the Earth and therefore apparently larger, so every solar eclipse was total or partial, and there were no annular eclipses.
- Due to tidal acceleration, the orbit of the Moon around the Earth becomes approximately 3.8 cm more distant each year.
- Millions of years in the future, the Moon will be too far away to fully occlude the Sun, and no total eclipses will occur.
- In the same timeframe, the Sun may become brighter, making it appear larger in size.
Estimates of the time when the Moon will be unable to occlude the entire Sun when viewed from the Earth range between 650 million and 1.4 billion years in the future.
What’s the rarest eclipse?
Solar and Lunar Eclipses A solar eclipse occurs when the Moon passes between the Sun and Earth, casting the Moon’s shadow on Earth. A solar eclipse can only happen during a New Moon. The Moon’s orbit is titled 5 degrees to Earth’s orbit around the Sun.
- Therefore a solar eclipse is a relatively rare phenomena and a Total or Annular eclipse even more rare, with the Hybrid eclipse the rarest of all.
- To understand the difference between a Total and Annular eclipse of the Sun, it must be understood that the Moon has an elliptical orbit around Earth.
- In fact, the Moon’s distance from Earth varies from a minimum of 221,000 to a maximum of 252,000 miles.
Therefore the Moon’s apparent size in our sky will vary by 13%, When the Moon’s orbit is toward its minimum distance from Earth, the Moon will appear visually as a larger disk than the Sun. If an eclipse occurs during this time, it will be a Total solar eclipse because the Moon has totally obscured the Sun’s disk, producing the beautiful solar corona ejecting outward from the Sun.
- One important element to remember though is that the Moon’s shadow will obviously become narrower as it is cast from the Moon to Earth (in a shape of a cone with the wide end being at the Moon and the narrow end on Earth).
- Therefore the path of totality on Earth is narrow.
- It is also very short-lived as the Moon is moving quickly away from its perfect location of being situated between the Sun and Earth.
An Annular solar eclipse is different than Totality in that it occurs when the Moon is closer to its maximum distance from Earth in its orbit. If an eclipse happens during this situation, the Moon will appear visually smaller than the Sun and its shadow cast will not be long enough to reach Earth.
- What reaches Earth is the antumbral or “negative” shadow.
- If you are within the antumbral shadow, you will see a solar eclipse where a thin ring or annulus of bright sunlight surrounds the Moon.
- Therefore Annular solar eclipses are still spectacular in that they are almost Total, but the solar corona is not seen due to the brightness of the annulus.
Like a Total eclipse, the Annular solar eclipse will have a narrow path on Earth with short duration, most often less than 10 minutes. A Hybrid eclipse is especially rare in that an Annular eclipse can change to a Total eclipse, or vice versa, along the eclipse path.
- Due to Earth’s curvature, Earth may move through the Antumbral shadow (Annular eclipse) and Umbral shadow (Total eclipse) along different points of the eclipse path.
- DO NOT observe a solar eclipse with the naked eye.
- Serious eye damage can result.
- Use approved solar filters or cut a pin hole in a shoe box and watch the Sun’s light cast through the pin hole onto a smooth surface such as cardboard.
The only portion of a solar eclipse which is safe to view without filters is the brief time during totality. Otherwise all partial solar eclipses need approved filters. For approved filters, look for a certification of International Standard ISO 12312-2,
When was last solar eclipse?
Eclipses
Date | Time of greatest eclipse (Terrestrial Time) | Magnitude |
---|---|---|
February 26, 2017 | 14:54:33 | 0.992 |
August 21, 2017 | 18:26:40 | 1.031 |
February 15, 2018 | 20:52:33 | 0.599 |
When was the last Blood Moon?
Home News Skywatching
The moon turned an eerie blood-red color in a total lunar eclipse overnight Sunday (May 15) that was visible to potentially millions of stargazers across four continents. The lunar eclipse, celebrated as the Super Flower Blood Moon, was the longest total lunar eclipse in 33 years, according to Space.com’s skywatching columnist Joe Rao.
- It was visible, weather permitting, from a wide swath of the world that spanned the Americas, Antarctica, Europe, Africa and the east Pacific.
- You can see amazing photos of the Super Flower Blood Moon from skywatchers with clear skies to see it.
- During the lunar eclipse, the full moon spent about 85 minutes inside the Earth’s umbra, or darker, shadow, according to Space.com columnist Joe Rao.
That’s compared with 96 minutes (opens in new tab) in August 1989, according to TimeandDate.com. Even New Zealand, eastern Europe and the Middle East got a subtle view of the penumbral, or lightly shadowed, version of the eclipse. But it was the Blood Moon that caught the attention of people around the world. The blood moon is seen during a penumbral lunar eclipse in Santiago, on May 15, 2022. (Image credit: Martin Bernetti / AFP) Riste Spiroski caught a view of the moon in Macedonia at 4:45 a.m. local time. “It looks like Saturn, with a long thin cloud in front of her, while the partial eclipse is happening — and you can see it clearly. This photo of the Super Flower Blood Moon eclipse (in partial stage) was captured by photographer Riste Spiroski in Macedonia, with a wisp of clouds giving the moon a Saturn-like appearance, on May 15, 2022. (Image credit: Riste Spiroski ) Some Space.com readers commented on the beauty of the eclipse.
- Beautiful view of the moon from Tucson, Arizona,” wrote one reader Bod Read.
- Michelle Jensen, another reader, used a smartphone to capture the eclipse from New Prague, Minnesota, roughly 45 minutes south of Minneapolis.
- Caught a few neat shots of the beginning of the eclipse.
- It’s nothing fancy, but I thought it was pretty cool that my phone picked that much up,” Jensen wrote.
You can see the photo below. The Super Flower Blood Moon lunar eclipse is caught in partial phase over New Prague, Minnesota on May 15, 2022 in this photo by skywatcher Michelle Jensen. (Image credit: Michelle Jensen) The timing of the Super Flower Blood Moon depended upon your location.
TimeandDate.com (opens in new tab) said the partial eclipse phase of the moon eclipse began May 15 at 10:28 p.m. EDT (0228 GMT on May 16). It reached the Blood Moon peak May 16 at 12:11 a.m. EDT (0411 GMT). Then the event ended at 1:55 a.m. EDT (0555 GMT). The penumbral eclipse started and ended an hour earlier than the total eclipse.
Several webcasts discussed the art and science of the Blood Moon, for people outside the viewing zone, in cloudy conditions or otherwise unable to see the show in person. “The things that are awe-inspiring, almost spiritual, don’t require modern technology,” Slooh astronomer Bob Berman said during the astronomy webcaster’s live broadcast.
As the Blood Moon shone live in remotely operated telescopes streaming live to Slooh, the company’s director of curriculum talked about how light around our planet gets refracted and falls upon the moon’s surface. “You’re watching the sunrises and sunsets that are occurring on our planet, right now, with the light from those hitting the moon,” John Boisvert said.
Eclipse scientist Fred Espenak said the full moon was a so-called supermoon, taking into account the variability of perigees (closest approaches) and apogees (furthest approaches) the moon has to our planet. NASA, however, follows another definition suggesting that a supermoon occurs when the moon is within 90% of its closest approach, which the agency says next happens in June,
- Supermoon or no, the full moon turning red for a time attracted a lot of attention around the world.
- If you’re hoping to photograph the moon, or want to prepare your gear for the total lunar eclipse, check out our best cameras for astrophotography and best lenses for astrophotography,
- Read our guides on how to photograph a lunar eclipse, as well as how to photograph the moon with a camera for some helpful tips to plan out you lunar photo session.
Totality!Tonight’s #LunarEclipse, seen from Florida’s Space Coast against a beautiful field of stars. pic.twitter.com/7EiO4gH1ut May 16, 2022 See more From my Samsung galaxy s21Lunar eclipse may 15, 2022 pic.twitter.com/woAZdC77tb May 16, 2022 See more A huge crowd turned out for the lunar eclipse! A lovely Montréal park moment ❤️ So happy y’all got to see this pic.twitter.com/ToZwh7jPef May 16, 2022 See more Total lunar eclipse! Taken with an iPhone attached to my 8″ telescope.
🌕📱🔭 #lunareclipse2022 pic.twitter.com/MBweZp6Avk May 16, 2022 See more super blood moon lunar eclipse pic.twitter.com/GRudCig4eQ May 16, 2022 See more Lunar eclipse, if you squint hard enough pic.twitter.com/2qyF6UCcWV May 16, 2022 See more Lunar Eclipse tonight #EclipseLunar #Minnesota pic.twitter.com/HXF4D5rvaJ May 16, 2022 See more Editor’s Note: If you snap an amazing lunar eclipse photo (or your own eclipse webcast) and would like to share it with Space.com’s readers, send your photo(s), comments, and your name and location to [email protected],
Follow Elizabeth Howell on Twitter @howellspace, Follow us on Twitter @Spacedotcom and on Facebook, Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: [email protected]
- Elizabeth Howell, Ph.D., is a staff writer in the spaceflight channel since 2022.
- She was contributing writer for Space.com (opens in new tab) for 10 years before that, since 2012.
- Elizabeth’s reporting includes an exclusive with Office of the Vice-President of the United States, speaking several times with the International Space Station, witnessing five human spaceflight launches on two continents, working inside a spacesuit, and participating in a simulated Mars mission.
Her latest book, “Why Am I Taller?”, is co-written with astronaut Dave Williams. Elizabeth holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, a Bachelor of Journalism from Canada’s Carleton University and (soon) a Bachelor of History from Athabasca University.
When was the last solar eclipse in America?
Back-to-Back American Solar Eclipses! – Do you remember the total solar eclipse that crossed the continental United States from coast to coast on August 21, 2017? If you lived in, or traveled into, the 70-mile-wide path of totality, where the Moon completely blocked the Sun’s bright face and turned day into night for a few minutes, you undoubtedly remember it well.
If you were outside that path under clear skies somewhere else in North America (or northern South America), perhaps you saw a partial solar eclipse that day. The 2017 total solar eclipse was the first to touch the “Lower 48” since 1979 and the first to span the U.S. from coast to coast since 1918. Remarkably, another total solar eclipse is coming to North America on April 8, 2024, just seven years after the last one.
This time the Moon’s dark central shadow, about 115 miles wide, will cross Mexico, sweep northeast from Texas to Maine, and then darken the Canadian maritimes. A partial solar eclipse will again be visible to nearly everyone in North America fortunate to have cloud-free skies.
Even more remarkably, we’ll have a different type of solar eclipse in North America just six months earlier. On October 14, 2023, the Moon will again pass directly between Earth and the Sun — but this time it will not quite completely cover the solar disk, instead turning it into a thin “ring of fire.” This annular (Latin for ring-shaped) eclipse will be visible within a roughly 125-mile-wide path from Oregon to Texas and on into Mexico and northern South America.
And again, North Americans outside the path will be treated to a partial solar eclipse if the weather cooperates. During a partial solar eclipse (left), the Moon covers only part of the Sun’s bright face. During an annular eclipse (middle), the Moon passes directly in front of the Sun but appears too small to fully cover it, leaving a “ring of fire” still shining.
These first two photos were taken through a safe solar filter passing less than 1/100,000th of the light, which is why the sky appears black. During the total phase of a total solar eclipse, or totality (right), the Moon completely blocks the Sun’s bright face, turning day into deep twilight and revealing the magnificent solar corona — our star’s wispy outer atmosphere — in one of the most awesome sights in all of nature.
This last photo was taken without a solar filter, since the totally eclipsed Sun is only about as bright as the full Moon and just as safe to look at directly. Images courtesy Rick Fienberg, Sky & Telescope, and TravelQuest International.
What is the rarest celestial event?
photo source: wikipedia.org – A penumbral lunar eclipse occurs when the Moon passes through the outer part of Earth’s shadow, called the penumbra. A penumbral lunar eclipse can happen when two conditions are present: the Moon is in the Full Moon phase, and the Moon is imperfectly aligned with the Sun and Earth.
What would happen if a solar eclipse never ended?
The last time the world witnessed a total solar eclipse was in 2017, and its presence delighted enthusiastic sky watchers. But what if, instead of a rare phenomena, a total solar eclipse became an everyday thing? Would you live in complete darkness? When does a total solar eclipse occur? What would happen to the Moon? A dragon devouring the sun, a giant puma demon, a pair of sky wolves.
- Throughout history and across cultures, an eclipse has been interpreted as a perplexing or fearful event.
- Even the 2017 total eclipse raised claims of impending apocalypse by evangelist groups in the U.S.
- But what if the next eclipse didn’t end? In this scenario, we’re talking about a total solar eclipse, which only happens under very specific circumstances.
First, it has to be a New Moon new moon phase. Second, the Moon has to be at its closest position to Earth, also called perigee. And third, the Moon has to be directly in front of the Sun. This rare planetary alignment would suddenly become a normal occurrence.
But don’t worry, you wouldn’t live in the Moon’s shadow all the time. There are two parts of the Moon’s shadow. The umbra is the dark center, and the penumbra is the outside edge, where only part of the Sun is blocked by the Moon. The umbra has a diameter of 267 km (166 miles), which is about the size of the state of West Virginia in the U.S.
Because of the Earth’s axis, this large shadow would sweep across different parts of the globe during different seasons. The rest of the planet would be in the penumbra. You’d still get sunlight, just not as much as you used to, and life would certainly be a little dimmer.
- Existence on Earth is closely tied to the transition of day to night.
- A total solar eclipse would disrupt this pattern and wreak havoc on other natural cycles.
- Under the umbra, the temperature would drop about 5 degrees Celsius (10 F).
- Even minimal fluctuations have significant impact.
- Temperature changes and lack of sunshine are not great for agriculture, so we would have to get creative with growing our crops in this new cycle of light and dark.
We would also see an increase in seasonal affective disorder, or SAD. This subtype of depression occurs during long winter months in high latitudes with lack of sunshine. You’d probably feel some of the same hopelessness and loss of energy under the Moon’s shadow.
Though we’d have to come up with a new diagnosis, maybe eclipse affective disorder? In a typical total solar eclipse, the umbra moves across the globe from west to east, lasting only about 7.5 minutes. This is because the Moon rotates around the Earth, making a static eclipse impossible. So the only way we could see a permanent solar eclipse is if the Moon stopped rotating around the Earth.
Without its own trajectory, the Moon wouldn’t be able to resist the gravitational pull from Earth, and would eventually destroy us. If that were the case, then a total eclipse really would be a doomsday warning! Observing a total solar eclipse is a once in a lifetime opportunity.
Is lunar eclipse rare?
A lunar eclipse only occurs during a full Moon, when the Sun, Earth and Moon are all aligned. But despite the Moon only taking 29.5 days to orbit Earth and complete a cycle from full Moon to full Moon, there are only on average about three lunar eclipses every year.
How often is there a blood moon?
How rare is a Super Flower Blood Moon? – Given that a Super Flower Blood Moon is a combination of unusual characteristics, the exact conditions required for such an event do not come around very often. Another flower moon will not occur until next spring, as we head into the summer months.
Lunar eclipses, the phenomenon that causes the red ‘blood moon’ colouring, happen about three times a year on average, but do not always line up with the full moon in spring. Supermoons are based on the undulating orbit of the moon in relation to the earth, and happen at a rate that appears almost entirely random.
On average there are around four supermoons in a year but they often happen in batches. Sunday’s supermoon will be the first of four consecutive months with the lunar spectacle. All that means that we can’t expect another Super Flower Blood Moon for the remainder of 2022, and possibly a lot longer.
What’s a hybrid eclipse?
Solar eclipse of April 20, 2023 Solar eclipse Solar eclipse of April 20, 2023 Map Type of eclipseNatureHybrid-0.39521.0132Maximum eclipseDuration76 sec (1 m 16 s)Coordinates Max. width of band49 km (30 mi)Times ()Greatest eclipse4:17:56References (52 of 80)Catalog # (SE5000) One of the rarest Solar eclipses, a hybrid will occur on Thursday, April 20, 2023.
- A solar eclipse occurs when the Moon passes between Earth and the Sun thereby totally or partly obscuring the image of the Sun for a viewer on Earth.
- A total solar eclipse occurs when the Moon’s is larger than the Sun’s, blocking all direct sunlight, turning day into darkness.
- A Hybrid solar eclipse is a rare type of solar eclipse that changes its appearance as the Moon’s shadow moves across the earth’s surface.
Totality occurs in a narrow path across the surface of the Earth, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Totality for this eclipse will be visible in the peninsula and in Western Australia, eastern parts of, as well as and parts of the province of in Indonesia.
What are the 7 eclipses?
Earth–Moon system – A symbolic orbital diagram from the view of the Earth at the center, with the Sun and Moon projected upon the celestial sphere, showing the Moon’s two nodes where eclipses can occur. An eclipse involving the Sun, Earth, and Moon can occur only when they are nearly in a straight line, allowing one to be hidden behind another, viewed from the third.
Because the orbital plane of the Moon is tilted with respect to the orbital plane of the Earth (the ecliptic ), eclipses can occur only when the Moon is close to the intersection of these two planes (the nodes ). The Sun, Earth and nodes are aligned twice a year (during an eclipse season ), and eclipses can occur during a period of about two months around these times.
There can be from four to seven eclipses in a calendar year, which repeat according to various eclipse cycles, such as a saros, Between 1901 and 2100 there are the maximum of seven eclipses in:
- four (penumbral) lunar and three solar eclipses: 1908, 2038,
- four solar and three lunar eclipses: 1918, 1973, 2094.
- five solar and two lunar eclipses: 1934.
Excluding penumbral lunar eclipses, there are a maximum of seven eclipses in:
1591, 1656, 1787, 1805, 1918, 1935, 1982, and 2094.
When was last solar eclipse?
Eclipses
Date | Time of greatest eclipse (Terrestrial Time) | Magnitude |
---|---|---|
February 26, 2017 | 14:54:33 | 0.992 |
August 21, 2017 | 18:26:40 | 1.031 |
February 15, 2018 | 20:52:33 | 0.599 |
How many solar eclipses occur in a year?
A solar eclipse, especially a total one, can be seen from only a limited part of Earth, whereas the eclipsed Moon can be seen at the time of the eclipse wherever the Moon is above the horizon. In most calendar years there are two lunar eclipses; in some years one or three or none occur.
1901–2000: 228 eclipses, of which 145 were central (i.e., total or annular); 2001–2100: 224 eclipses, 144 central; 2101–2200: 235 eclipses, 151 central; 2201–2300: 248 eclipses, 156 central; 2301–2400: 248 eclipses, 160 central; 2401–2500: 237 eclipses, 153 central.
Any point on Earth may on the average experience no more than one total solar eclipse in three to four centuries. The situation is quite different for lunar eclipses. An observer remaining at the same place (and granted cloudless skies) could see 19 or 20 lunar eclipses in 18 years.
Over that period three or four total eclipses and six or seven partial eclipses may be visible from beginning to end, and five total eclipses and four or five partial eclipses may be at least partially visible. All these numbers can be worked out from the geometry of the eclipses. A total lunar eclipse can last as long as an hour and three-quarters, but for a solar total eclipse maximum duration of totality is only 7 1 / 2 minutes.
This difference results from the fact that the Moon’s diameter is much smaller than the extension of Earth’s shadow at the Moon’s distance from Earth, but the Moon can be only a little greater in apparent size than the Sun,
How many eclipses are there in a year?
How Often Do Solar and Lunar Eclipses Occur – Most years have four eclipses: the minimum number of eclipses in a year; 2 of these four eclipses are always solar eclipses. While rare, the maximum number of eclipses that can take place in a calendar year is seven.
- There are two or three eclipses during every eclipse season,
- At least one of these is always a solar eclipse, sometimes two.
- The same is true for lunar eclipses,
- Which order they come in depends on how each eclipse season coincides with the lunar (synodic) month,
- The lunar month is the period it takes the Moon to go through all the Moon Phases from a New Moon to the next, and it lasts, on average, 29.5 days.
This is five days less than an eclipse season. Therefore, there will always be at least one New Moon, resulting in a solar eclipse, and at least one Full Moon, resulting in a lunar eclipse, during each eclipse season. This is also why solar and lunar eclipses come in pairs—a solar eclipse always takes place either about two weeks before or after a lunar eclipse, and vice versa.