What is a variable star? It's a star that brightens and dim in a cycle that might last hours, or weeks, or months, or longer. Astronomers know millions!
A recent Hubble image reveals a spiral galaxy hosting a quasar. Typically, quasars are older galaxies that have grown very massive and are not spiral shaped.
ESA released new Mercury images from BepiColombo's final flyby of Mercury on January 8, 2025. The spacecraft will eventually go into orbit around Mercury.
Some cynics say that when you wish upon a star, that star is already dead. But don't listen to them! The stars you can see, and your dreams, are perfectly safe.
Members of the EarthSky community - including scientists, as well as science and nature writers from across the globe - weigh in on what's important to them.