Mars was once a warmer world of rivers, lakes and a thicker atmosphere, but after its internal dynamo died and the planet lost the magnetic shield that helps protect an atmosphere, the solar wind stripped much of its air away over billions of years, leaving the cold desert we see today

The familiar version goes like this. Early Mars was a warmer world with rivers and lakes and a thick atmosphere. Its internal dynamo died, the planet lost the magnetic field that had shielded it, and the solar wind stripped the air away over billions of years, leaving the cold desert we see now. The outline […]