On the other hand, each planet is also different from the others in its group. For example, each of the four rocky planets has a different kind of atmosphere. An atmosphere is a blanket of gas that covers a planet.
Different gases trap different amounts of heat from the sun, which means that each planet has a different temperature. For example, Venus is the hottest planet because it has a thick and heavy atmosphere covered with clouds. The clouds let in energy from the sun, and this makes Venus’s surface temperature hotter than most ovens!
The rocky planets have many other differences. They are each different sizes, and they also have different features on their surfaces. In addition, Earth and Mars spin at about the same rate—one rotation every twenty-four hours—but Mercury and Venus both take months to rotate just once.
A detailed view of Venus’s cloudy atmosphere
• Surface They are rocky and solid.
• Rings They do not have planetary rings.
• Moons They have few or no moons.
• Size They are small compared to other planets—less than 8,000 miles in diameter. even so, earth is more than 2.5 times bigger than Mercury!
• Planet life Earth is the only planet known to have living things.
• Temperatures In this group, Venus is the hottest planet (average temperature: 867° F) while Mars is the coldest planet (average temperature: -85° F).
• Locations Mercury is closest to the sun, while Mars is farthest from the sun.