Mars: A Rocky Planet Like Earth

Mars is the fourth planet from the sun, and the last rocky planet before encountering the gas planets in the outer solar system. Only Earth and Mars lie in the "Goldilocks" zone, where it is neither too hot nor too cold for life as we know it to exist. While we don't yet know if Mars ever developed life, this rocky world is the only other planet where it is even possible for humans to walk around and explore . . . and maybe even live one day in the far future.

Mars Rocks: The Stories They Tell

When we walk around on our own planet, we don't usually pay too much attention to the rocks around us, but if we did, they'd be able to tell us all kinds of stories about how the Earth has developed and changed throughout its history.

Planetary geologists are scientists who spend a lot of time studying rocks to learn about the stories they tell. For instance, a rock's structure and the materials it's made of can tell us about conditions on a planet when the rocks were formed. Some rocks are only formed in the presence of water, so finding these rocks on Mars can be extremely exciting--where there was water, there may have been life. And even if no life ever developed, the history of water on Mars--and where it went--will help us understand conditions and climate changes on Earth.

Mars inspires many of today's musicians. If you can think of other Mars references in the music you listen to, please let us know.

• In the seventies during the time of the Viking missions to Mars, David Bowie wrote a song called "Life on Mars."
• Britney Spears features the Martian terrain in her music video, "Oops! I Did It Again."
• Vangelis, who wrote the music for the film Chariots of Fire, is now writing music inspired by the 2001 Mars Odyssey mission.
• The UK band Blur has written a song about Mars that might be the first music broadcast from the Red Planet in 2003 from the European Space Agency's Beagle 2 lander, part of the Mars Express mission.
• The Transfixions have also written a song called Ares4, which tells of the day when humans might one day go to Mars.