Discover the cosmosEach day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation:Have you ever seen a complete auroral oval?
You can’t see one from the ground because it makes toolarge a circlearound one ofEarth’s magnetic poles.
But spacecraft high abovethe Earthcan see them.
Thefeatured videofromESAandCAS‘s roboticSMILE spacecraftshows not only afull auroral oval, but usingultraviolet light, one that occurred during the day.
The time-lapse covers about an hour in late July and shows visually howvariableand turbulentaurorasreally are.
The points of light on the sides aredistant stars that appear to move only becauseSMILE’s cameraview shifts as the spacecraftorbitsthe Earth.
A goal of SMILE is tobetter understandhow the Sun’s wind interacts with the Earth’s magnetosphere— and so better understand how to protect astronauts, spacecraft, and ground-basedelectrical gridsfromsolar storms.
Tomorrow’s picture: a ghost