As promised, NASA made a huge announcement regarding Mars thanks to its Mars Atmosphere and Volatile Evolution mission, or MAVEN. It revealed that the Martian atmosphere is thinning at a fast rate every second. The culprit? The same solar winds that whip our system, including Earth. The data gathered by MAVEN can help scientists piece together the mystery of how Mars become the cold and arid planet it is today, and perhaps offer hints about future habitable planets in solar systems much similar to ours.
NASA doesn’t have a time machine, but it can do math pretty well. By calculating backwards from the rate of atmospheric loss and taking into consideration other factors, scientists were able to theorize that, at one point in time, Mars was indeed a warm, wet, and habitable planet. A stark contrast to the red neighbor we know it today. And the prime suspect in Mars’ chronic disease is the very same solar wind that produces the breath taking aurora on Earth. As well as on Mars apparently.
Solar winds carry charged particles, mostly protons and electrons, in streams traveling at speeds of about one million miles per hour. These interacts with Mars’ atmosphere, producing ions, which are then jettisoned into space. Based on MAVEN’s data, Mars is losing as much as 100 grams of gas per second. That’s a quarter-pounder of gas. And that’s only on average. Big solar storms, like those that hit the planet last March, can accelerate the loss even further.
So if you count backwards, Mars would have, at one point in time, probably billions of years ago, had an atmosphere so thick that it could hold water inside. Without that atmosphere, the water escaped, leading to the death of the planet.
For now, the Earth is safe from suffering a similar fate. Despite also being exposed to solar winds, our planet’s magnetic field, which is substantially stronger than Mars’, protects us from those effects. Not to mention it also gives us a pretty light show every time.