The inner and outer planets are all different from each other: different distances from the Sun, different revolution and rotation periods, size and the number of satellites.
This table shows some characteristics of the planets in the Solar System:
2nd conditional
would + past participle
On Venus, we would weigh...
| Planet | Distance from the Sun1 | Revolution period 2 | Rotation period 2 | Diameter of equator 3 | Number of satellites |
| Mercury | 0,39 | 88 days | 59 days | 4880 | 0 |
| Venus | 0,72 | 224,7 days | 243 days | 12104 | 0 |
| Earth | 1 | 365,26 days | 23 h 56 min | 12756 | 1 |
| Mars | 1,52 | 687 days | 24 h 37 min | 6787 | 2 |
| Jupiter | 5,2 | 11,86 days | 9 h 50 min | 142800 | 63 |
| Saturn | 9,54 | 29,46 days | 10 h 14 min | 120000 | 61 |
| Uranus | 19,2 | 84,01 days | 17 h 14 min | 51800 | 27 |
| Neptune | 30,1 | 164,8 days | 16 h 7 min | 49500 | 13 |
(1) Average distance in AU (2) According to terrestrial values (3) Average values in km
| Mercury | Venus | Earth | Mars |
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| Mercury is named after the messenger of the Roman gods. It has no atmosphere and because of this its average temperature varies, depending on exposure to the Sun (-170 ºC at night and 425 ºC during the day). Mercury does not contain water. It has 0.055 times the mass of Earth. On Mercury, we would weigh 0.37 times more than we weigh on Earth. |
Venus is named after the Roman goddess of love and beauty. It has a very dense atmosphere that generates a greenhouse effect. Its average temperature is 480 ºC. Venus could contain water vapour. It has 0.815 times the mass of Earth. On Venus, we would way weigh 0.88 times less than we weigh on Earth. |
Our planet is named after Tellus or Terra, the Roman goddess of the Earth. Earth's atmosphere has greenhouse gases that allow the planet to maintain an average temperature of 15 ºC. Earth is the only planet in the Solar System where water is found in all three states. It is also the only planet where life has been found. It has a mass of 6 x 424 kg. |
Mars is named after the Roman god of war. In the past, its atmosphere was possibly more compact, but now it is very light. Its average temperature is -63 ºC Mars has ice at both poles. It has 0.108 times the mass of Earth. On Mars, we would weigh 0.38 times less than we weigh on Earth. |
| Jupiter | Saturn |
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| Jupiter is named after the most important Roman god. Its atmosphere has cloud storms that give the planet its characteristic colours. Its average temperature is -120 ºC. It has a ring made of dust particles. It has 317.9 times the mass of Earth. On Jupiter, we would weigh 2.64 times more than we weigh on Earth. |
Saturn is named after the Roman god of agriculture. Its atmosphere is composed of hydrogen with some helium and methane. Saturn is the least dense planet in the Solar system (it would float in water). Its average temperature is -125 ºC. Saturn's characteristic rings are made of ice, rocks and dust. It has 95.2 times the mass of Earth. On Saturn, we would weigh 1.15 times more. |
| Uranus | Neptune |
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| Uranus is named after the Roman god of the sky. Its atmosphere has hydrogen and methane. Methane absorbs the red light and gives the planet its characteristic blue-green colour. Its average temperature is -210 ºC. Uranus is surrounded by eleven rings. It has 14.6 times the mass of Earth. On this planet we would weigh 1.17 times more than on Earth. |
Neptune is named after the Roman god of the sea. Its atmosphere is composed of hydrogen, helium, water vapour, and methane, which gives it a blue colour. Neptune, like Jupiter, has storms and the average temperature is -200 ºC. Neptune is surrounded by four thin rings made of dust particles. It has 17.2 times the mass of Earth. One Neptune, we would weigh 1.18 times more. |
Activity 16
Calculate how much someone would weigh on each of the planets in the Solar System, if they weigh 50 kg on Earth.
Activity 17
Choose the planet in the Solar System with more characteristics in common with the Earth.
Activity 18
Match the following concepts to find interesting data about Jupiter's four largest moons.
