Why is Venus called Earth's "sister planet"?
Venus is often called Earth's "sister planet" or "twin" because of 3 major similarities:
- Mass, i.e. how much they weigh
- Composition, i.e. what material they're made of
Further, Venus is the closest planet to Earth within the solar system.
Earth’s diameter is
In this image, you have to look carefully to notice that Earth (right) is slightly larger:
As with their sizes, the mass of Venus is only slightly lesser than that of Earth—Earth weighs only
Both Venus and Earth have metal cores surrounded by a mantle of silica rock (also common in rocky moons and asteroids), and then a thin crust.
Despite these similarities, Earth and Venus are also quite different, causing some to nickname Venus "Earth's evil twin."
The major differences are those that make Venus too hostile to support life as Earth does: temperature and atmosphere.
Venus's average temperature is
While Earth's atmosphere is composed of oxygen and nitrogen (with only small amounts of