This is an image of the sun.
It was taken by an instrument called a coronagraph on NASA's STEREO mission.
Our bright star is hidden beneath the black circle.
The coronagraph blocks the sun with an occulting disk
so it can observe the star's much-fainter outer atmosphere - the corona.
This region shows background stars
and ripples caused by diffracted light bending around the occulting disk.
Scientists study these images to learn more about the activity in the corona.
Solar wind flows outwards along these 'streamers'.
Here is a coronal mass ejection, or CME, which is a huge magnetic eruption blasting from the sun.
The CME flings solar particles at near-light speeds towards STEREO causing a 'snow' effect in the images.
These powerful eruptions can dramatically affect the space environment,
which, in turn, can affect satellites, astronauts, and Earth.