The sun. We see it nearly every day, and yet most of us spend a considerable amount of time trying to keep it out of our eyes or off our skin.
NASA, on the other hand, has been staring straight into the sun for years now. The agency launched the Solar Dynamics Observatory (SDO) in 2010 to capture images of the sun, which it does every 12 seconds in 10 different wavelengths. Scientists are using the SDO to learn more about the sun and to improve predictions for solar flares and coronal mass ejections, which can affect satellites orbiting Earth.
In the three years since its launch, the SDO has observed the sun as it ramps up to "solar maximum," which is the peak of the star's 11-year solar activity cycle. To demonstrate this increase in the sun's activity, NASA this week released a video that puts together many of the images taken by the SDO. The time-lapsed video shows two images of the sun per day for three years. It also has some nice background music ("A Lady's Errand of Love" by Martin Lass).