You think we have tsunami problems? Imagine a wave of superheated plasma and magnetic energy over 7 1/2 times taller than Earth* rushing toward you at 560,000 miles per hour.
That’s what the twin STEREO satellites spotted when it got the first very good image of something called a a magnetohydrodynamical wave (also called a solar tsunami) back in February. Scientists have seen these waves before, but they’ve never been entirely sure if they weren’t seeing some sort of shadow or image artifact. Thanks to the better imaging from STEREO, they now know solar tsunamis are real and spectacular.
Okay, so where’s the practical angle here? Well, solar tsunamis are caused by Coronal Mass Ejections — big honking eruptions on the sun that blast billions of tons of gas toward us and the rest of the planets. CMEs can reach speeds of up to 1.6 million MPH, which means that we’ll get a touch over 58 hours of warning* before we get hit by one of the faster ones.
CMEs play hell with electrical systems when they strike the Earth’s magnetosphere. They can potentially disable satellites, damage sensitive electronics, and cause widespread power outages. Obviously, we’d like to know when one’s heading our way as soon as possible (as opposed to having to relyalmost solely on a single 11 year-old satellite)and that’s where STEREO helps us. Thanks to that mission, we can get a better look at an Earthbound CME almost as soon as it erupts and we’ll know more about it (size and speed, especially) than we’ve known in the past.
Also, we get amazingly cool videos like this.
*As always, feel free to recheck my math here (or, for that matter, any math you see on The Shack. I try to get it right, but math is far from my strongest subject. Unlike the Climate Research Unit, I don’t mind if you check my work and correct my mistakes.
Category: Hey, Mr. Science Guy!