Global Warming the Key to Life on Mars

US scientists have thought up a new way to create a second home - by warming up the atmosphere of Mars.

Mars - which used to be warm and wet - has an atmosphere rich in carbon dioxide. But because the red planet's atmosphere is so thin, the planet is now freezing cold.

But Margarita Marinova, of Nasa Ames research centre in California, and colleagues report in the Journal of Geophysical Research-Planets that artificially created greenhouse gases could set the Martian climate simmering. "Bringing life to Mars and studying its growth would contribute to our understanding of evolution, and the ability of life to adapts and proliferate on other worlds," Dr Marinova said.

"Since warming Mars effectively reverts it to its past, more habitable state, this would give any possibly dormant life on Mars the chance to be revived."

She and her colleagues created a computer model of the Martian atmosphere, and tested it with a series of fluorine-based gases. They found that a gas called octafluoropropane could begin a process of global warming on Mars.

This would take hundreds or even thousands of years. But since the raw materials already exist there, some future space mission could start to turn up the heat in a world frozen for at least 2bn years.