The recent volcanic eruption in Hawaii reminds us that Earth is still an active planet — there’s a lot going on. And that’s the case for several other worlds as well. There’s evidence of active volcanoes on Venus, for example. And Io, one of the big moons of Jupiter, is covered with hundreds of them.

No one is quite sure, though, about whether there’s any volcanic activity on Mars. No one’s ever seen any eruptions on the planet. But there is some evidence of activity fairly recently — on the geological time scale. And that suggests that Mars isn’t dead yet.

Mars is home to several giant volcanic mountains. There’s no doubt that they were quite busy in the distant past. But Mars has lost most of the heat left over from its formation, so there’s not a lot to keep them going. And the Martian crust isn’t made of overlapping plates, which create volcanic activity on Earth.

The biggest volcano is Olympus Mons. It covers an area half the size of New Mexico, and towers about 15 miles above the surrounding plains. It probably formed billions of years ago, and kept on going. Some studies say it last erupted about 20 million years ago. Others say it staged some small eruptions just two million years ago. Either way, that means it could erupt again in the future.

Look for Mars close to the lower right of the Moon this evening, and sticking close to the Moon throughout the night. The planet looks like a bright orange star.

Script by Damond Benningfield