- from Solar System
Mars, Venus, and Mercury are the planets most like Earth, meaning they’re spinning balls of rock, too.
Venus is about the same size as Earth. Mars has seasons and ice-capped poles, just like Earth. Plus, they’re in our neighborhood—not far from the Sun. But Venus has a surface hot enough to melt lead, and hurricane-force dust storms whip around Mars. From sunrise to sunrise on Mercury takes six Earth months. Both the differences and the similarities tell scientists a lot about Earth. Looking at our neighbors is like asking over and over, “What if Earth were...?”