More Fun on the Sun

Yesterday, I posted a quick video of a small prominence on the Sun, taken at CCSSC's Solar Observatory. Of course, if you really want to see a prominence in glorious detail, a telescope in space - which avoids distortions from Earth's atmosphere - is a great way to go. Japan's Hinode spacecraft and its Solar Optical Telescope provides some wonderful examples. The movies linked through that news article show movements in solar "polar crown" prominences for hours at a time, creating beautiful, dynamic displays of the plasma dancing along magnetic fields.

Follow up:

These polar crown prominences are a special type of prominence, which show up relatively near the Sun's northern and southern poles. A lot of magnetic-field activity takes place there, which is why prominences there are common. This also means that the gas trapped in prominences there will sometimes be able to escape, as the interaction of magnetic fields disrupts the magnetic-field-loop which holds the plasma.

These loops can hold billions of tons of gas, which, when released, shoots out into the solar system as a coronal mass ejection. Those are the sorts of critters that, when they reach Earth, can damage satellites, disrupt radio communications, and so forth. These impacts on our lives here on Earth make it important for us to monitor "space weather", that is, the levels of solar (and other) activity that could affect us.

A variety of solar scientists are on the job, and NASA provides a number of important tools, with many new missions planned. Not only do they constantly monitor solar activity, but they also work to better understand what causes that activity. An example is the upcoming SUMI mission, which will be blasted up in a high arc over most of Earth's atmosphere. For eight minutes, it will have a clear view of the Sun's "transition region" above the solar photosphere, where much of the activity (like prominences and coronal mass ejections) is thought to originate. By measuring magnetic fields in these regions, scientists will be taking new steps to understand why they work as they do - and how we can predict their behavior. Perhaps someday, we'll be able to forecast the space weather with high accuracy. Then again, you know how hard it is to forecast Earth weather...