hey, where is our atmosphere going?
A major part of what makes our planet habitable are the magnetic fields produced by the dynamo deep in its innards. And it’s this magnetosphere which protects us from cosmic rays and diminishes the effect that solar winds have on our atmosphere. Without it, charged particles from the Sun would strip away our air faster than on say, Mars or Venus where magnetic fields aren’t nearly as strong as on Earth. Right? Wait, why are some of the geophysicists in the audience looking around with a nervous shrug? Did they just discover that our planet is actually losing its atmosphere faster than our magnetically deficient planetary neighbors?
Actually, they think they did. During a conference, scientists working on analyzing the atmospheres of Earth, Venus and Mars compared notes and found that surprisingly, while our magnetosphere does protect us from the full onslaught of cosmic rays and solar flares, we’re still seeing atmospheric erosion faster than either of our nearby planets. That erosion amounts to 50 septillion molecules per second, which is somewhere in the neighborhood of a hundred pounds or so. How exactly do we lose that much air?
Earth’s magnetic field interacts with the solar wind, drawing out energy that gets funneled into the planet’s atmosphere along its magnetic field lines.
“The wind has to flow around this large magnetic obstacle in its path,” Russell said. “The two are not friction-free.” In addition to triggering aurorae, the process causes Earth’s atmosphere to heat up to the point where atmospheric gases can escape along the field lines, where they are then picked up by the solar wind.
Should you be alarmed about our air eroding at this rate? Probably not because it would take at least several billion years until our atmosphere becomes just a ghost of its former self, giving us plenty of time to figure out exactly why we’re seeing a greater amount of atmospheric erosion despite our strong magnetosphere as well as abandon the planet when our Sun begins to expand and cooks it to a crisp in the far future.