Astronomers measure a star’s brightness using the apparent magnitude system, where lower values indicate brighter stars.

Stargazers will be treated to a rare seven-planet alignment in February. This is what scientists hope to learn.

A handful of planets in the solar system are expected to line up in the night sky for a few days in January 2025. Here's when ...

Because planets always appear in a line, the alignment isn't anything out of the norm. What's less common is seeing so many ...

"We have by and large been ignoring triples in models and simulations — we're just starting to understand how these types of ...

"A parade of planets, also sometimes referred to as a planetary alignment, is when several planets in our solar system appear to line up in the sky from our perspective here on Earth," John Conafay, ...

Hubble Space Telescope mapped Andromeda, revealing a chaotic history shaped by mergers. A 2.5-billion-pixel mosaic shows 200 ...

So I grabbed my camera, ran outside, and looked up just as Mars was supposed to emerge from the Moon's curved horizon. Seen ...

But it is a rare class of star that NASA's Hubble Space Telescope ... appears in the night sky alongside the northern lights has now been ... New Data on Atmosphere from Earth to the Edge of ...

Mars will seem to disappear behind the full wolf moon Monday for many sky-gazers. Throughout January, also look up to see ...