Little green men. Mysterious canals. Unexplained geologic features. There are a lot of wild stories about the planet Mars. It may not be home to an alien civilization, but Mars is still a fascinating planet that has intrigued scientists for decades. There’s a lot we don’t know about Mars, but scientists have answered a few questions:

Q: Is there life on Mars?
A: Probably not. Mars is a lot like Earth, more so than any other planet in the Solar System. Because of this, many people thought it might support life, just like our planet does. Unlike some other planets, Mars has some water, which also made scientists believe there might be life there. Water, after all, is thought to be necessary for most kinds of life. If Mars has water, maybe it has life! However, there have been many missions to Mars, and none of them has found any evidence of life. And while Mars may have once had a lot of water, it has very little now. Not enough to support life.

Q: Is it hot or cold on Mars?
A: That depends. Mars’s orbit around the Sun is highly elliptical, or shaped like an oval. This means that sometimes Mars is really close to the Sun, and sometimes it is really far away. Because of this, temperatures on Mars can be anywhere from -143 degrees Fahrenheit to 17 degrees Fahrenheit.

Q: Why is Mars red?
A: Mars looks red because of iron in its surface soil. This iron reacted with oxygen and formed rust. That made the planet look red.

Q: What does Mars look like?
A: Mars looks kind of strange. The southern part is very old and has a lot craters, like the Moon. The northern part is flatter and is thought to be younger. There is a boundary between the two halves. Scientists don’t know why the two halves are so different, but some think that something may have hit the planet shortly after it formed.

Q: What about the face on Mars? And those canals?
A: When the picture of the face on Mars was taken, people thought it might be a statue built by Martians. However, when scientists studied the image closer, they realized it was just a design on the planet, caused by wind wearing away parts of the planet’s surface. As for the canals: In the 1800s, astronomers thought they something on Mars that looked like canals humans have built here on Earth. They though this could mean Mars also had life, intelligent life (like us) who could build things. However, when scientists sent spacecraft to Mars to take pictures, they found there weren’t any canals at all. It seems the images astronomers saw were just optical illusions, or tricks of the eye. We don’t know what caused them.