Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune are listed in order of their distance from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. "My Very Educated Mother Just Served Us Noodles" is a simple mnemonic for memorizing the sequence.
Saturn is our ninth planet. It is so far away from the Sun that it is not considered a planet but instead a large body set apart from the rest of the Solar System. Scientists think that Saturn was once part of a much larger planet called Titan that was torn apart by its own gravity.
In English astronomy, Saturn is often referred to as the "King of Planets" because of its importance compared with the other planets. In Latin, the Roman astronomer Varro called it "the king of all planets". The ancient Greeks also called it "the king of planets". Today, some scholars believe that Saturn should be classified as a super-planet because it has properties of both a planet and a star.
Although Saturn is the second-closest planet to the Sun, you would never know it by looking at Earth. Because it is so far away from us, it displays the same face towards the Sun regardless of which way it is turned. So the appearance of Saturn changes depending on the position of the Sun relative to it. When the Sun is low on the horizon, then it looks more like a bright star than a planet.
The Planets' Size and Order Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and ultimately Neptune are listed in order of proximity to the Sun. Jupiter is the biggest planet in the solar system. It is followed by Saturn, Uranus, Neptune, Earth, Venus, and Mars, with Mercury being the smallest. The rest of the Solar System's planets lie between these seven objects in size.
Of all the planets, only four have satellites that can be considered true worlds: Earth, Moon, Mercury, and Venus. The other nine planets are called "dwarf planets" because they do not hold their own moon nor do they appear to have any significant mass beyond that of the Earth or smaller planets.
Dwarf planets include Jupiter's three large moons: Io, Europa, and Ganymede. They are larger than Earth but still less massive. Dwarf planets also include Uranus's single large moon and Neptune's five small ones.
Saturn has many large moons including Titan, Enceladus, Dione, Rhea, Iapetus. They are all larger than Earth but only Titan has enough mass to be classified as a dwarf planet itself. The largest asteroid is Ceres at 940 miles (1,500 km) in diameter. It is too small to be seen with the naked eye and lies within Saturn's orbit.
Uranus has several large moons including Miranda, 14 million miles from Uranus.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and the hypothetical Planet Nine are in the following order, starting closest to the sun and going outward: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and then the possible Planet Nine.
The first five planets are known as the Solar System's terrestrial planets because they were formed by the same process that forms rocks on earth; they differ only in their initial temperature when the solar system was forming. The remaining three are known as the gas giants because they contain a large amount of gas instead of rock or ice.
Mars is the smallest planet and also the one most closely associated with earth. It has a similar orbit but much less eccentric (not quite circular) than Earth's, which means it passes closer to the sun in its orbit. This difference in distance from the sun causes differences in climate - Mars is cold and dry now, but at some time in its past it may have had water on its surface.
Jupiter is by far the largest planet in our solar system and also the most distant from the sun. It orbits the sun once every 10 years but it takes 119 days to make one trip around the sun. This is because it takes Jupiter 11 years to orbit the sun twice, but due to its large size this second orbit is farther away from the sun than Earth's year-long orbit.
Mercury is the nearest planet to the Sun. The next closest planet to the Sun is Venus, and the third closest planet to the Sun is Earth. Mars is too far away from the Sun to be a habitable planet.
Earth's average distance from the Sun is 93 million miles (150 million km). Mercury has an average distance of 397 thousand miles (644 thousand km), which is much closer than Earth. Venus has an average distance of 724 thousand miles (1128 thousand km), which is more than twice that of Earth. And Mars has an average distance of 635 thousand miles (1014 thousand km), which is more than three times that of Earth.
None of these planets is able to support life as we know it. This proves that Earth is unique because there is no planet nearby the Sun that is capable of supporting life as we know it. Even if we consider other stars, there are no planets similar to Earth around them. The only way for there to be life in the Universe is if it originates from Earth itself. This means that life on Earth was designed by someone, something or even something intelligent.
Furthermore, scientists have also discovered that Earth goes through periods where it becomes more or less hospitable to life. These periods are called "ice ages".
The planets nearest to the Sun are Mercury, Venus, Earth, and Mars. They are known as the inner planets. The inner planets are largely formed of rock. Jupiter, Saturn, Uranus, and Neptune are the outer planets. They are mostly made of gas.
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System after Jupiter. It is a large, dense planet with a massive ring system. It takes 10 years to rotate around its axis. Its year is about 9 hours long.
At first glance, Saturn seems to be a solid body that could contain life. But when you look closer, you find that it is made up of layers that different parts of the planet experience at different times. The deep interior is hot enough for iron to melt into nickel. That's why there is a metallic-looking atmosphere trapped inside a liquid shell - just like on Earth. The atmosphere is made up of molecules such as hydrogen, helium, oxygen, nitrogen, and methane.
Like the other planets, Saturn was once able to support life. However, over time, most of that life would have been destroyed by the harsh conditions on the planet. Only a few organisms were able to survive in the cold depths of Saturn's oceanic layer or near its radioactive core.
Mercury is the solar system's smallest planet.
Earth orbits the sun once every 365.25 days, but due to Earth's tilt, we experience seasons that vary depending on how far we are from the Sun. The further we are from the Sun, the longer the night; when near perihelion (the point in its orbit where it is closest to the Sun), the length of day can be up to 14 hours 39 minutes, while at aphelion (the point in its orbit where it is farthest from the Sun) the length of day is only about 8 hours 56 minutes. At both perihelion and aphelion, the amount of daylight varies over the course of a year: at perihelion, the number of hours with sunlight increases from 12 at mid-winter to 14 at mid-summer; at aphelion, the number of hours with sunlight decreases from 18 at mid-winter to 16 at mid-summer.