Space

Mars Dried Out Because Its Magnetic Field Is So Weak

Mars once had oceans, but its magnetic field just wasn't strong enough to keep the atmosphere - and most of the water - from blowing away.

Mars Dried Out Because Its Magnetic Field Is So Weak
NASA

How did Mars go from wet to dry?

NASA's MAVEN probe says: blame the sun and a wimpy magnetic field. (Video via NASA)

When solar flares erupt, high-energy particles batter the planets. (Video via NASA)

Earth's powerful magnetic field shields the atmosphere. But with its weak field, Mars takes the full brunt. (Video via NASA)

So the atmosphere blew away and so did most of the water. (Video via NASA)

This video includes images from NASA.