Four and a half billion years ago, our Solar System was formed out of a huge cloud of dust and gas.
Top 10 Largest Bodies in The Solar System
| Body | Max Diameter (KM) | Max Diameter (Miles) | Size Compared with Earth |
|---|---|---|---|
| 1. Sun | 1,392,140 | 865,036 | 109.136 |
| 2. Jupiter | 142,984 | 88,846 | 11.209 |
| 3. Saturn | 120,536 | 74,898 | 9.449 |
| 4. Uranus | 51,118 | 31,763 | 4.007 |
| 5. Neptune | 49,528 | 30,775 | 3.883 |
| 6. Earth | 12,756 | 7,926 | 1.000 |
| 7. Venus | 12,104 | 7,521 | 0.949 |
| 8. Mars | 6,805 | 4,228 | 0.533 |
| 9.Ganymede | 5,262 | 3,270 | 0.413 |
| 10. Titan | 5,150 | 3,200 | 0.404 |
Most of the planets have been observed since ancient times. The exceptions are Uranus, discovered on 13 March 1781 by the British astronomer Sir William Hershel; Neptune, founded by German astronomer Johann Galle on 23 September 1846; and, outside the Top 10, the former planet Pluto.
Top 10 Longest Years in The Solar System
| Body | Length of Year ( Years) | Length of Year ( Days) |
|---|---|---|
| 1. Eris | 561 | 135 |
| 2. Makemake | 305 | 124 |
| 3. Haumea | 281 | 340 |
| 4. Pluto | 247 | 336 |
| 5. Neptune | 164 | 289 |
| 6. Uranus | 84 | 6 |
| 7. Saturn | 29 | 163 |
| 8. Jupiter | 11 | 315 |
| 9. Ceres | 4 | 219 |
| 10. Mars | 1 | 322 |
Top 10 Longest Days in The Solar System
| Body | Days (LOD) | HRS (LOD) | Mins (LOD) | Secs (LOD) |
|---|---|---|---|---|
| 1. Venus | 243 | 0 | 26 | 60 |
| 2. Mercury | 58 | 15 | 30 | 14 |
| 3. Sun | 25 | 0 | 0 | 0 |
| 4. Pluto | 6 | 9 | 17 | 17 |
| 5. Eris | 1 | 1 | 53 | 46 |
| 6. Mars | 24 | 37 | 26 | |
| 7. Earth | 23 | 56 | 41 | |
| 8. Makemake | 22 | 29 | 17 | |
| 9. Uranus | 17 | 13 | 55 | |
| 10. Neptune | 16 | 6 | 14 |
Top 10 Largest Planetary Moons
1. Ganymede / Jupiter
Discovered by Galileo on 11 January 1610. Ganymede is thought to have a surface of ice of about 97 km (60 miles) think. Launched in 1989, NASA’s Galileo probe reached Ganymede in June 1996.
2.Titan / Saturn
Titan is larger than Mercury and pluto. We have no idea what its surface looks like because it has such a dense atmosphere, but radio telescope observations suggest that it may have ethane ‘oceans’ and ‘continents’ of ice or other solid matter.
3. Callisto / Jupiter
Possessing a similar composition to Ganymede, Callisto is heavily pitted with craters, perhaps more so than any other body in the Solar System.
4. Io / Jupiter
Io has a crust of solid sulphur with massive volcanic eruptions in progress, hurling sulphurous materials 300 km (186 miles) into space.
5. Moon / Earth
Our own satellite is a quarter of the size of Earth, the 5th largest in the Solar System and, to date, the only one to have been explored by humans.
6. Europa / Jupiter
Although Europa’s ice-covered surface is apparently smooth and crater-free, it is covered with mysterious black lines, some of them 64 km (40 miles) wide and resembling canals.
7. Triton / Neptune
Triton is getting progressively closer to Neptune, and it is believed that in several million years the force of the planet’s gravity may full it apart, scattering it into a form like the rings of Saturn.
8. Titania / Uranus
The Largest of Uranus’s 27 Moons. Titania was discovered by William Herschel on 11 January 1787. It has a snowball-like surface of the ice. Its size estimate was revised by data from Voyager 2.
9. Rhea / Saturn
Saturn’s 2nd largest moon was discovered on 23 December 1672 by Jean-Dominique Cassini. Voyager 1 confirmed that its icy surface is pitted with craters, one of them 225 km (140 miles) in diameter.
10. Oberon / Uranus
Oberon was discovered by Herschel at the same time as Titania, and given the name of the fairy king husband of Queen Titania. Data from Voyager 2 relegated Oberon from 9th to 10th place in this list.
