Scientists believe there may be dozens more dwarf planets awaiting discovery. Here is a brief look at the eight planets in our Solar System. Included are quick facts and links so you can find out more about each planet. Mercury: Mercury is the closest planet to our Sun, at just 58 million km 36 million miles or 0. But despite its reputation for being sun-baked and molten, it is not the hottest planet in our Solar System scroll down to find out who that dubious honor goes go!
Mercury is also the smallest planet in our Solar System, and is also smaller than its largest moon Ganymede, which orbits Jupiter. And being equivalent in size to 0. But this may have something to do with its incredible density, being composed primarily of rock and iron ore. Here are the planetary facts:. Venus: Venus is the second closest planet to our Sun, orbiting at an average distance of million km 67 million miles or 0.
Venus is The surface gravity, which is 8. Earth: Our home, and the only planet in our Solar System that we know of that actively supports life. Our planet is the third from the our Sun, orbiting it at an average distance of million km 93 million miles from the Sun, or one AU. Given the fact that Earth is where we originated, and has all the necessary prerequisites for supporting life, it should come as no surprise that it is the metric on which all others planets are judged.
Mars: Mars is the fourth planet from the sun at a distance of about million km million miles or 1. In many ways, Mars is similar to Earth, which can be seen from its similar rotational period and tilt, which in turn produce seasonal cycles that are comparable to our own. The same holds true for surface features. Like Earth, Mars has many familiar surface features, which include volcanoes, valleys, deserts, and polar ice caps. But beyond these, Mars and Earth have little in common.
Jupiter: Jupiter is the fifth planet from the Sun, at a distance of about million km million miles or 5. Jupiter is also the most massive planet in our Solar System, being times the mass of Earth, and two and half times larger than all the other planets combined.
It is a gas giant, meaning that it is primarily composed of hydrogen and helium, with swirling clouds and other trace gases. In fact, the combination of incredibly high pressure and coriolis forces produces the most violent storms ever witnessed.
Saturn: Saturn is the sixth planet from the Sun at a distance of about 1. The final straw for Pluto's planet status came in , when astronomers discovered another object called Eris that did not meet the International Astronomical Union's definition of a planet, but was nonetheless larger than Pluto. Farthest planet in the Solar System. Who Neptune. What 4,,, kilometre s.
There are only two comets, which have been observed at more than one close approach to the Sun, which move further away from the Sun than Halley's comet. It has a period of years and a maximum distance from the Sun of There are many comets which have only been seen to make one approach to the Sun. Many of these have very elongated orbits. These comets have orbits that take them out to more than AU but these large distances are very approximate.
Comets are believed to arise from a cloud of many millions of objects known as the Oort cloud in circular orbits around the Sun at distances of up to 50, AU. These objects would then represent the outermost reaches of the Solar System.
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