It turns out Mars is literally having the life, or at least atmosphere, sucked right out of it. On Thursday NASA announced that solar storms are stripping away Mars’ atmosphere. The leakage is slow, only about half a pound per second, but over time that can really add up.
Scientists believe that at one point Mars’ atmosphere was as thick, if not thicker, than the current atmosphere on Earth. These days, however, the atmosphere on Mars is rather thin.
The biggest atmosphere leaks occur when Mars is hit by solar storms, which strip away the upper atmosphere. This insight is especially important because it could help explain what happened to Mars’ atmosphere. Even if Mars was slowly bleeding away half a pound of atmosphere over the last 4.5 billion years, the leakage would not have been enough to reduce the atmosphere to its current levels.
Solar storms, however, are believed to have been much more violent and frequent in the early years of the solar system. Billions of years ago the sun shone more brightly and ultraviolet rays were much stronger. These solar storms could have stripped away Mars’ atmosphere early on.
When solar winds hit the atoms in the upper atmosphere, the winds essentially knock the particles loose and then sweep them away. The slow leakage, on the other hand, is caused by atoms losing electrons. When this happens the atoms themselves are pushed away by the planet’s magnetic fields.
Knowing why the so-called Red Planet lost its atmosphere is essential for understanding why Mars is not a lush planet with liquid water. NASA believes that lakes and rivers once flowed across Mars, but now it appears that most of the water on the planet is locked up in its polar caps.
Just as a thicker atmosphere on Earth is slowly causing the planet to warm, a thinner atmosphere on Mars would have lead to cooling. And when the planet cooled, the once flowing liquid water turned to ice.