NASA's Solar Dynamics Observatory

The Sun is a star, one of over a hundred billion stars in our galaxy alone. It's also the closest star to Earth and, at about 93 million miles away, it's the most accessible object in space.

It's not just a pretty light in the sky—it has an enormous impact on Earth and its inhabitants. The Sun has been exploding since it was born 4.6 billion years ago, propelling solar winds that can cause geomagnetic storms when they hit Earth's atmosphere and ionosphere.

This explosion is known as a solar flare: A sudden release of energy that happens when magnetic fields become tangled up or "knotted" together. The Solar Dynamics Observatory (SDO) observes these flares and other activity on the Sun from space; it also monitors ultraviolet emissions from the corona—the outermost layer of the Sun's atmosphere—and measures how these emissions affect our planet's climate by interacting with Earth's atmosphere.

SDO was launched into orbit on February 11th, 2010; since then, it has collected data about how our star affects our planet's space weather system—the physical processes that occur in near-Earth space due to their interactions with one another (such as geomagnetic storms). This information will help scientists better understand