Bad Astronomy

A Different Angle on the Sun

SOHO + SDO view of the Sun
The Sun blows off little steam…or a few hundred million tons of plasma, as seen by SDO and SOHO. The bright “star” on the right is actually the planet Mars.

Photo by NASA/SDO/SOHO

I’ve written twice in the past few days about the Sun and its incredible power. In a funny coincidence, not long after I posted the beautiful pictures of the “quiet” Sun yesterday, the folks at NASA put out a very, very cool video showing a May 1, 2013 solar eruption as seen from three different spacecraft, showing how well they work together:

I love this! I tend to show images and videos from spacecraft that are isolated; that is, each comes from one observatory. But this video makes it clear why we have so many spacecraft observing the Sun. Solar Dynamics Observatory zooms in on the Sun’s disk, so we can see features on the surface. The Solar and Heliospheric Observatory (SOHO) takes a wider view, displaying the Sun’s environment. In fact, SOHO has different detectors that show different zoom factors.

Working in cahoots, the two observatories can watch an eruptive prominence blast off the surface and expand into a coronal mass ejection (CME), flinging a billion tons of material into space.

Enter STEREO, a pair of spacecraft in an orbit that is taking them in opposite directions, headed for the far side of the Sun. They literally see this event from the other side, giving us a perspective that is impossible from Earth.

All three together provide a powerful view of our star. Given that it is the anchor of our solar system, the provider of all the light and heat we receive—and can, if it so chooses, blow off a huge flare or CME that could seriously affect our power grid and our satellites—I think studying it every way we can is A Good Idea.