Mars was once warm, wet and possibly beautiful. Today it’s cold and barren, a place that isn’t exactly welcoming to life. But how did it get that way, and what can we learn from the planet’s tragic evolution? Scientists have the answers thanks to NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission, which has revealed how the Red Planet transitioned into the desolate alien world it is today.
According to data revealed by MAVEN, Mars’ upper atmosphere is slowly leaking into space, and it’s all thanks to solar wind. The sun giveth, and it also taketh away. Measurements taken by the probe indicate solar winds strip away about 100 grams of gas every second, which isn’t significant for a single day, but it makes a big difference over billions of years.
“We’ve seen that the atmospheric erosion increases significantly during solar storms, so we think the loss rate was much higher billions of years ago when the sun was young and more active,” said John Grunsfeld, astronaut and associate administrator for the NASA Science Mission Directorate.
“Understanding what happened to the Mars atmosphere will inform our knowledge of the dynamics and evolution of any planetary atmosphere,” Grunsfeld added. “Learning what can cause changes to a planet’s environment from one that could host microbes at the surface to one that doesn’t is important to know, and is a key question that is being addressed in NASA’s journey to Mars.”
NASA says that solar winds can travel about one million miles per hour, wreaking havoc on whatever is in its path. When the magnetic field carried by solar winds flow past Mars, an electric field is generated, leading to electrically charged gas atoms in Mars’ atmosphere, which are then shot out toward space. Bye-bye atmosphere.
To see a visualization of what these solar winds are doing to Mars, check out the video below. Suddenly Mars doesn’t look like the friendliest place to visit, and it makes Curiosity’s journey to the planet all the more impressive.