About Mars and the loss of atmosphere

NASA just announced another groundbreaking discovery regarding the history of Mars.

Data from the MAVEN spacecraft revealed how Mars loses 100 grams of its atmosphere every second.

Why? solar winds, and obviously solar storms, which increase the loss rate even more.

Mars vs Solar Storm
Mars vs Solar Storm

As explained in the official article from NASA:

[quote]The solar wind is a stream of particles, mainly protons and electrons, flowing from the sun’s atmosphere at a speed of about one million miles per hour. The magnetic field carried by the solar wind as it flows past Mars can generate an electric field, much as a turbine on Earth can be used to generate electricity. This electric field accelerates electrically charged gas atoms, called ions, in Mars’ upper atmosphere and shoots them into space.[/quote]

This is, of course, an extremely interesting discovery, which helps scientists to understand how Mars lost its atmosphere.

However, browsing my news feeds, I stumbled upon a good number of misleading headlines. This is not HOW Mars lost it’s atmosphere, it’s one of the responsible factors.

In fact, the whole purpose of the MAVEN mission was to analyze the ionic loss caused by solar winds and determine the rate at which it happens. Many other factors contribute to this phenomena. For instance, low gravity allows molecules to escape, while asteroid collisions can eject massive amounts of particles into space.

So that’s what’s happening to Mars, but…

We do have an atmosphere too, and we’re much closer to the Sun than Mars is! Is this happening to Earth as well? Are we going to lose our atmosphere too??

Well, yes, in a while. Indeed, we are currently losing atmosphere at a much higher rate than Mars. However, we have a strong magnetic field that protects us from solar winds and limits the loss of ions.

Mars vs Earth Solar Wind
Mars vs Earth Solar Wind


For instance, if we consider the lightest elements that compose our atmosphere, namely hydrogen and helium, the escape rate can sound alarming. We’re in fact losing about three kilograms of hydrogen and 50 grams of helium per second. However, putting this data in relation with the mass of our atmosphere, which is around  5.15×1018 kg, it immediately become insignificant. 

Let me give you a scientifically irrelevant time perspective. If you do the math, going from the Earth’s mass value to zero at 3 Kg per second would take more than 50 billion years.

Still, nothing to worry about.


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