Introduction The planetary system we call home is located in an outer spiral arm of the Milky Way galaxy. Our solar system consists of our star, the Sun, and everything bound to it by gravity – the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune; dwarf planets such as Pluto; dozens of moons; and millions of asteroids, comets, and meteoroids.
- Beyond our own solar system, there are more planets than stars in the night sky.
- So far, we have discovered thousands of planetary systems orbiting other stars in the Milky Way, with more planets being found.
- Most of the hundreds of billions of stars in our galaxy are thought to have planets of their own, and the Milky Way is but one of perhaps 100 billion galaxies in the universe.
While our planet is in some ways a mere speck in the vast cosmos, we have a lot of company out there. It seems that we live in a universe packed with planets – a web of countless stars accompanied by families of objects, perhaps some with life of their own.
- 1 What makes up the solar system?
- 2 What are 4 things that make up our solar system?
- 3 What is the new planet?
What makes up the solar system?
Our Solar System Our solar system is made up of a star—the Sun—eight planets, 146 moons, a bunch of comets, asteroids and space rocks, ice, and several dwarf planets, such as Pluto. The eight planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
Mercury is closest to the Sun. Neptune is the farthest. Planets, asteroids, and comets orbit our Sun. They travel around our Sun in a flattened circle called an ellipse. It takes the Earth one year to go around the Sun. Mercury goes around the Sun in only 88 days. It takes Pluto, the most famous dwarf planet, 248 years to make one trip around the Sun.
Moons orbit planets. Right now, Jupiter has the most named moons—50. Mercury and Venus don’t have any moons. Earth has one. It is the brightest object in our night sky. The Sun, of course, is the brightest object in our daytime sky. It lights up the moon, planets, comets, and asteroids.
What are the 5 main objects in our solar system?
Star, planets, satellites, comets. Asteroids.
What are 4 things that make up our solar system?
One of Billions – Our solar system is made up of a star, eight planets, and countless smaller bodies such as dwarf planets, asteroids, and comets.2
What is meant by the solar system class 6?
- The Solar system is a group of objects bound together, gravitationally, to the Sun.
- The Solar system comprises the Sun, eight planets and their satellites, asteroids, and meteoroids.
- The eight planets in our Solar system are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, which are in increasing order of distance from the Sun.
- Earth is the third closest planet to the Sun and it is also the fifth-largest planet in our Solar system.
- The Earth’s shape is called Geoid.
- The Moon is Earth’s satellite.
- Asteroids are the numerous tiny celestial bodies that constantly revolve around the Sun. They are found especially between the orbits of Mars and Jupiter.
- Meteoroids are small pieces of rocks revolving around the Sun.
What are the 6 largest moons in our solar system?
Our Own, Quite Respectable, Moon – Earth’s moon (Image: Claudio Divizia/Shutterstock) The moon is about one-fourth the size of Earth; the Earth is about 13,000 kilometers in diameter, and the moon is about 3,500 kilometers in diameter. You may think that Earth and the moon are close together, but they’re not: the real distance between Earth and the moon is about 30 Earth diameters away from the moon—about 380,000 kilometers. The Earth’s Moon is the only celestial body, other than Earth, that humans have set foot on. (Image: Castleski/Shutterstock) When we look at the moon, we can see the basics of it. Its surface is dominated by craters, and from those craters, we understand the history of impacts throughout the solar system.
- When you look at the full moon, you can see that there are some dark regions.
- These are the marae, which were originally believed to be lunar seas but we now know to be lava-filled plains.
- A lot of them have circular boundaries around them, indicating that they are lava-filled plains due to very large impacts that punched through the crust of the moon, and the lava then flowed up and filled the circular basin.
Compared to the other large moons of the solar system, our moon is quite respectable. The seven large moons are, in decreasing order of size: Ganymede, Titan, Callisto, Io, our moon, Europa, and Triton. Ganymede, Callisto, Io, and Europa are the four Galilean moons that Galileo saw in 1610.
Titan is the large moon of Saturn, and Triton is the large moon of Neptune. The seven large moons are, in decreasing order of size: Ganymede, Titan, Callisto, Io, our moon, Europa, and Triton. This is a transcript from the video series New Frontiers: Modern Perspectives on Our Solar System, Watch it now, on The Great Courses.
These large moons are comparable to the rocky planets. Ganymede and Titan are even larger than Mercury, and all of these are larger than Pluto.
How many objects are in our solar system?
Objects of the Solar System – Galileo was the first person to observe the night sky through a telescope. This was in the early 1600s. Since then, hundreds and thousands of scientists have been studying the night sky, the movement of celestial bodies, and the universe.
- We now have a better understanding of planets and other celestial bodies.
- In view of many recent discoveries, and our changing understanding of planetary systems, scientists have felt it necessary to create a new definition for planets and other bodies in the solar system.
- The objects of the solar system (except satellites) are placed in three distinct categories: planets, dwarf planets, and small solar-system bodies,
According to the new definition, there are eight planets in the solar system. In the order of their increasing distance from the sun, they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, Pluto and Ceres are placed under the category of dwarf planets,
More dwarf planets may be included under this category in future. Asteroids, comets, and other small bodies are placed under the category of small solar-system bodies,1. Sun The sun is a medium-sized star. It is a huge ball of gases, mainly hydrogen. There is a massive nuclear reaction taking place in the sun, converting the hydrogen gas into helium gas.
This reaction gives out huge amounts of light, heat, and other forms of energy. The diameter of the sun is about 1.4 million kilometres. It is so big that it could hold more than a million planets of the size of the Earth! There are much bigger stars than the sun in the universe.
- One of the biggest stars that we know of is Betelgeuse.2.
- In early times, people studied the night sky, by observing the objects with the naked eye, and then through telescopes.
- In the night sky, planets appear as bright specks of light, much like stars.
- They do not twinkle.
- While the stars show no visible change in their position in the sky, the planets seem to move or ‘wander’ with respect to the stars.
Hence, they were named planets, which means ‘wanderers’ in Greek. Unlike stars, planets do not emit light of their own. They appear bright like stars in the night sky because they reflect light from the sun (like the moon does). They are also closer to us than the stars and, therefore, the light coming to us from the planets is brighter and bigger (i.e., they are generally bigger blobs of light) and hence does not appear to twinkle.
Mercury, Venus, Mars, Jupiter, and Saturn are quite bright and can be seen with the naked eye. The other planets, namely Uranus and Neptune, are very faint and can be seen only with a telescope. Uranus can sometimes be seen with the naked eye. Mercury, Venus, Earth, and Mars are called inner planets because they are much closer to the sun as compared to Jupiter, Saturn, Uranus, and Neptune, which are called outer planets.3.
These include asteroids, comets, and other small bodies.
What are the 3 parts of the solar system?
Asteroid groups – Asteroids in the asteroid belt are divided into and based on their orbital characteristics. are sharp dips in the distribution of asteroid orbits that correspond to with Jupiter. are asteroids that orbit larger asteroids. They are not as clearly distinguished as planetary moons, sometimes being almost as large as their partners (e.g.
That of ). The asteroid belt includes, which may have been the source of Earth’s water. are located in either of Jupiter’s (gravitationally stable regions leading and trailing a planet in its orbit); the term trojan is also used for small bodies in any other planetary or satellite, are in a 2:3 resonance with Jupiter; that is, they go around the Sun three times for every two Jupiter orbits.
The inner Solar System contains, many of which cross the orbits of the inner planets. Some of them are,
What is below our solar system?
Beyond the 8 planets that we normally think of as our solar system, there is a group of asteroids and dwarf planets called the Kuiper Belt. Beyond that is a region called the Oort Cloud, where most comets come from.
Is there a super Earth?
Is there life on super-Earths? The answer could lie in their cores Atmospheric water has been discovered by European scientists on a planet 124 light-years away from us. It is possible that clouds form and even rain falls on this faraway world, dubbed K2-18 b.
The planet lies within what astronomers call the habitable zone, with a temperature that could allow life to thrive there. The rocky planet is eight times the mass of Earth and known as a super-Earth. This is the name given to planets between the size of Earth and Neptune. ‘Super-Earths are actually the most common type of planet in our galaxy,’ said Dr Ingo Waldmann, extrasolar planet explorer at University College London, UK, one of the scientists,
Super-Earths are also possible residences of alien life. The first planet orbiting an active star beyond our own solar system was discovered in 1995. Since then, the Kepler space telescope has increased the rate of discovery, with 4,000 such exoplanets now known.
Initially, large gaseous giants near their stars, ‘hot Jupiters,’ seemed most common, but as more and more super-Earths piled up, scientists became puzzled by their abundance. ‘The early exoplanet systems found were the simple ones, with one hot Jupiter going around a star. We weren’t really expecting anything like super-Earths, but then they started to show up,’ said Dr Waldmann.
‘We know as good as nothing about super-Earths at the moment, because they don’t exist in our own solar system.’ Before NASA’s Kepler space telescope, most exoplanets were thought to be gas giants and hot Jupiters. After the nine-year mission, the majority of exoplanets now known are actually rocky planets with a size ranging from Earth to Neptune. Image credit – NASA/Ames Research Center/Natalie Batalha/Wendy Stenzel Diverse Most of these mysterious planets are discovered when they transit in front of small stars and cause the starlight to dim.
- From this, researchers can work out the mass and the radius of the planet and the evidence suggests that these worlds are incredibly diverse in their make-up.
- Super-Earths can be all sorts of things really,’ said Dr Waldmann.
- He gives the example of 55 Cancri e, a planet with a lava ocean at temperatures hot enough to melt iron, and Gliese 1214 b, which is a potential ocean planet consisting mostly of water.
Scientists deduce which molecules are in a planet’s atmosphere by studying starlight as it passes through. Knowing what goes on inside these distant planets is far more difficult. ‘We can look at the surface of the star to get hints about the chemistry and composition of a planet, which gives us hints as to how much iron or silicon may be in a planet,’ said Dr Razvan Caracas, planetary mineralogist at École Normale Supérieure de Lyon in France.
This is important because depending on whether there is a solid core, perhaps made from nickel or nickel and iron, and a liquid metal outer core, a planet might or might not have a magnetic field. Earth’s magnetic field keeps most of the sun’s radiation away from us by deflecting a stream of charged particles so they don’t reach our planet’s surface.
Researchers believe this sort of shielding would be necessary for life to emerge elsewhere. Dr Caracas supervised a project called which ran computer simulations of various iron-nickel mixtures at extremely high pressures to see how they behaved. These are the metals that likely sit at the core of super-Earths, but it is unclear whether iron and nickel would mix together, separate into different layers or become liquid at the intense pressures inside large planets.
By understanding the type of core structure that could arise from proportions of nickel and iron, scientists hope to understand what could be happening inside super-Earths based on what we find out about their chemical composition. Protection
‘Two cores might behave differently, and one might have a magnetic field and the other wouldn’t,’ explained Dr Caracas. ‘A stronger magnetic field gives you better protection on the surface from the sun’s rays, and that means you can make organic molecules that are more complex.’ Dr Guillaume Fiquet, an experimental physicist at CNRS and Sorbonne University in Paris, France, is also trying to understand super-Earth interiors through a project called,
‘When people talk about the habitability of planets, this is often related to the presence of a magnetic field, which itself is related to having some kind of metallic core or at least conductive material (in vigorous motion),’ he said. He is investigating how materials like iron behave under pressures inside super-Earths, which could be up to 1 terapascal, three times the pressure within Earth.
This squashes atoms together and can change the properties of materials, meaning that our knowledge about how they behave on Earth may not apply to exoplanets. ‘Exoplanets can be larger planets than Earth, which means the pressures and temperatures could be much greater,’ Dr Fiquet said, ‘That forces us to try to develop new tools to access special states of matter that we don’t know yet.’ Dr Fiquet sheds light on this mystery by recreating the high temperatures and extreme pressures that may lie at the heart of these exotic planets.
- He does this on vanishingly small scales, firing powerful lasers at tiny specs of metal or squeezing them between microscopic diamond anvils.
- This experimental setup has helped him draw melting curves for elements like iron that probably sit at the core of super-Earths under intense pressure.
- These can then be used to refine the material properties that scientists use to infer what goes on in the interiors of super-Earths and ultimately know more about their bulk chemical composition, says Dr Fiquet.
Meanwhile, Dr Waldmann leads research to assist astronomers in dealing with super-Earth data from future exoplanet discoveries using artificial intelligence (AI). We need AI, said Dr Waldmann, ‘because all this data is extremely difficult to analyse and we will be stretched to the limit of what is possible to do by hand.’ Super-Earths are prime candidates for the existence of extraterrestrial life.
His AI, developed through the project, will help astronomers interpret observations of chemicals in an exoplanet’s atmosphere, for example, and tell them whether a super-Earth is interesting for further study or not. ‘That is the holy grail,’ Dr Waldmann added. ‘Finding chemical signatures in the atmosphere of a super-Earth due to life.
Hopefully we will in the next couple of years, or decades.’ The research in this article was funded by the EU. If you liked this article, please consider sharing it on social media. : Is there life on super-Earths? The answer could lie in their cores
What is the new planet?
The telescopes of the SPECULOOS Southern Observatory in the Atacama Desert, Chile. The telescopes were used to confirm and characterize a new planet discovered by NASA, which led to the discovery of another nearby planet. ESO/P.Holárek hide caption toggle caption ESO/P.Holárek The telescopes of the SPECULOOS Southern Observatory in the Atacama Desert, Chile. The telescopes were used to confirm and characterize a new planet discovered by NASA, which led to the discovery of another nearby planet. ESO/P.Holárek An international team of scientists says it has discovered two new “super-Earth” type planets about 100 light-years away, one of which may be suitable for life. Researchers at Belgium’s University of Liège announced Wednesday that they found another one while using Earth-based telescopes to confirm the existence of a different planet initially discovered by a NASA satellite in the same solar system. NASA’s satellite found planet LP 890-9b, which is about 30% larger than Earth and orbits its sun in just 2.7 days. Francisco Pozuelos, a researcher at the Institute of Astrophysics of Andalusia and one of the main co-authors of the paper, said in a news release that the planet could be suitable to life despite being a mere 3.7 million miles from its sun. Earth, by comparison, is located over 93 million miles away from our sun.
“Although this planet orbits very close to its star, at a distance about 10 times shorter than that of Mercury around our Sun, the amount of stellar irradiation it receives is still low, and could allow the presence of liquid water on the planet’s surface, provided it has a sufficient atmosphere,” Pozuelos said.
“This is because the star LP 890-9 is about 6.5 times smaller than the Sun and has a surface temperature half that of our star.” NASA’s Transiting Exoplanet Survey Satellite (TESS) searches for exoplanets orbiting nearby stars by monitoring light levels of thousands of stars. New planets are discovered when a planet passes in front of one of those stars, causing the light being monitored to dim. ULiège scientists then follow up NASA’s findings with ground-based telescopes to confirm and characterize the planets.
How old is the solar system 2022?
Formation and evolution – Main article: Artist’s impression of the early Solar System’s, out of which Earth and other Solar System bodies formed The Solar System formed 4.568 billion years ago from the gravitational collapse of a region within a large,
- This initial cloud was likely several light-years across and probably birthed several stars.
- As is typical of molecular clouds, this one consisted mostly of hydrogen, with some helium, and small amounts of heavier elements fused by previous generations of stars.
- As the region that would become the Solar System, known as the, collapsed, caused it to rotate faster.
The centre, where most of the mass collected, became increasingly hotter than the surrounding disc. As the contracting nebula rotated faster, it began to flatten into a with a diameter of roughly 200 AU (30 billion km; 19 billion mi) and a hot, dense at the centre.
- The planets formed by from this disc, in which dust and gas gravitationally attracted each other, coalescing to form ever larger bodies.
- Hundreds of protoplanets may have existed in the early Solar System, but they either merged or were destroyed or ejected, leaving the planets, dwarf planets, and leftover,
Due to their higher boiling points, only metals and silicates could exist in solid form in the warm inner Solar System close to the Sun, and these would eventually form the rocky planets of Mercury, Venus, Earth, and Mars. Because metallic elements only comprised a very small fraction of the solar nebula, the terrestrial planets could not grow very large.
- The giant planets (Jupiter, Saturn, Uranus, and Neptune) formed further out, beyond the frost line, the point between the orbits of Mars and Jupiter where material is cool enough for volatile icy compounds to remain solid.
- The ices that formed these planets were more plentiful than the metals and silicates that formed the terrestrial inner planets, allowing them to grow massive enough to capture large atmospheres of hydrogen and helium, the lightest and most abundant elements.
Leftover debris that never became planets congregated in regions such as the asteroid belt, Kuiper belt, and Oort cloud. The is an explanation for the creation of these regions and how the outer planets could have formed in different positions and migrated to their current orbits through various gravitational interactions.
The, a planetary nebula similar to what the Sun will create when it enters its white dwarf stage Within 50 million years, the pressure and density of hydrogen in the centre of the protostar became great enough for it to begin, The temperature,, pressure, and density increased until was achieved: the thermal pressure counterbalancing the force of gravity.
At this point, the Sun became a star. The main-sequence phase, from beginning to end, will last about 10 billion years for the Sun compared to around two billion years for all other phases of the Sun’s pre- life combined. Solar wind from the Sun created the and swept away the remaining gas and dust from the protoplanetary disc into interstellar space.
- As helium accumulates at its core the Sun is growing brighter; early in its main-sequence life its brightness was 70% that of what it is today.
- The Solar System will remain roughly as it is known today until the hydrogen in the core of the Sun has been entirely converted to helium, which will occur roughly 5 billion years from now.
This will mark the end of the Sun’s main-sequence life. At that time, the core of the Sun will contract with hydrogen fusion occurring along a shell surrounding the inert helium, and the energy output will be greater than at present. The outer layers of the Sun will expand to roughly 260 times its current diameter, and the Sun will become a,
- Because of its increased surface area, the surface of the Sun will be cooler (2,600 K (2,330 °C; 4,220 °F) at its coolest) than it is on the main sequence.
- The expanding Sun is expected to vaporize Mercury as well as Venus, and render Earth uninhabitable (possibly destroying it as well).
- Eventually, the core will be hot enough for helium fusion; the Sun will burn helium for a fraction of the time it burned hydrogen in the core.
The Sun is not massive enough to commence the fusion of heavier elements, and nuclear reactions in the core will dwindle. Its outer layers will be ejected into space, leaving behind a dense, half the original mass of the Sun but only the size of Earth.
How many planets are there in solar system?
There are eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.