APOD: 2025 March 5 Б Seven Sisters versus California
5.03.2025

On the right, dressed in blue, is the Pleiades. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and most easily visible open clusters on the sky. The Pleiades contains over 3,000 stars, is about 400 light years away, and only 13 light years across.

Betelgeuse Imagined
1.01.2020

Why is Betelgeuse fading? No one knows. Betelgeuse, one of the brightest and most recognized stars in the night sky, is only half as bright as it used to be only five months ago.

Blue Stragglers In NGC 6397
22.06.2000

In our neck of the Galaxy stars are too far apart to be in danger of colliding, but in the dense cores of globular star clusters star collisions may be relatively common. In fact...

The Cave Nebula in Infrared from Spitzer
11.06.2019

What's happening in and around the Cave Nebula? To help find out, NASA's orbiting Spitzer Space Telescope looked into this optically-dark star-forming region in four colors of infrared light. The Cave Nebula...

Waves of the Great Lacerta Nebula
14.09.2022

It is one of the largest nebulas on the sky -- why isn't it better known? Roughly the same angular size as the Andromeda Galaxy, the Great Lacerta Nebula can be found toward the constellation of the Lizard (Lacerta).

IC 1805: Light from the Heart
17.09.2004

Sprawling across hundreds of light-years, emission nebula IC 1805 is a mix of glowing interstellar gas and dark dust clouds. Only about 7,500 light-years away, stars were born in this region whose nickname - the Heart Nebula - derives from its suggestive shape (seen here sideways).

Super Earths May Circle Other Stars
20.03.2006

Are "super-Earths" common around other star systems? Quite possibly. Unexpected evidence for this came to light recently when a planet orbiting a distant star gravitationally magnified the light of an even more distant star.

The Colorful Clouds of Rho Ophiuchi
3.12.2013

The many spectacular colors of the Rho Ophiuchi (oh'-fee-yu-kee) clouds highlight the many processes that occur there. The blue regions shine primarily by reflected light. Blue light from the star Rho Ophiuchi and nearby stars reflects more efficiently off this portion of the nebula than red light.

A Scorpio Sky Spectacular
11.09.2007

If Scorpio looked this good to the unaided eye, humans might remember it better. Scorpio more typically appears as a few bright stars in a well known but rarely pointed out zodiacal constellation. To get a spectacular image like this, though, one needs a good camera, color filters, and a digital image processor.

Colors of the Moon
11.11.2020

What color is the Moon? It depends on the night. Outside of the Earth's atmosphere, the dark Moon, which shines by reflected sunlight, appears a magnificently brown-tinged gray. Viewed from inside the Earth's atmosphere, though, the moon can appear quite different.