Today's Astronomy Picture of the Day is our first ever three-dimensional picture of the sun. You'll need some red-blue 3D glasses to see it (I got mine from a McDonald's Happy Meal a few years ago, so they don't need to be expensive!).
Why do we need a 3-D view of the sun? From the Earth, the sun looks like a flat disk. We know it is spherical, and when we see a sunspot or activity of the sun, we can make a decent guess as to where it is based on our model of the sun. But many things stick out from the surface of the sun, like prominences, flares, and the solar corona. And when we see a solar flare or coronal mass ejection, it is a bit of a guess if these storms are headed for the Earth.
With the newSTEREO spacecraft, it should be possible to make better predictions as to if a solar storm is going to hit the Earth. And, since solar storms can disrupt radio, damage satellites, endanger astronauts, and even cause power outages, these are important advances in predictions of solar storms.
So, grab your 3D glasses and enjoy a safe look at the sun online!