Supernova Remnant Simeis 147
13.01.2022

It's easy to get lost following the intricate, looping, twisting filaments in this detailed image of supernova remnant Simeis 147. Also cataloged as Sharpless 2-240 it goes by the popular nickname, the Spaghetti Nebula.

Carina Nebula North
31.01.2022

The Great Carina Nebula is home to strange stars and iconic nebulas. Named for its home constellation, the huge star-forming region is larger and brighter than the Great Orion Nebula but less well known because it is so far south -- and because so much of humanity lives so far north.

APOD: 2024 January 29 Б The Pleiades: Seven Dusty Sisters
29.01.2024

The well-known Pleiades star cluster is slowly destroying part of a passing cloud of gas and dust. The Pleiades is the brightest open cluster of stars on Earth's sky and can be seen from almost any northerly location with the unaided eye.

Moon Pi and Mountain Shadow
14.03.2025

What phase of the Moon is 3.14 radians from the Sun? The Full Moon, of course. Even though the Moon might look full for several days, the Moon is truly at its full phase when it is Pi radians (aka 180 degrees) from the Sun in ecliptic longitude.

APOD: 2026 August 8 Б A Messier Moment for Tempel 2
8.08.2026

Which of these is not a comet? You guessed it - the one on the right is a globular star cluster. The diffuse greenish coma of periodic comet 10P/Tempel 2 is at left in the frame.

Doomed Star Eta Carinae
11.06.1996

Eta Carinae may be about to explode. But no one knows when - it may be next year, it may be one million years from now. Eta Carinae's mass - about 100 times greater than our Sun - make it an excellent candidate for a full blown supernova.

APOD Turns Eleven
16.06.2006

The first APOD appeared eleven years ago today, on 1995 June 16. Although garnering only 14 page views on that day, we are proud to estimate that APOD has now served over 400 million space-related images over the last eleven years.

The Magellanic Stream
15.08.2013

In an astronomical version of the search for the source of the Nile, astronomers now have strong evidence for the origin of the Magellanic Stream. This composite image shows the long ribbon...

Big Dipper over Pyramid Mountain
21.11.2017

When did you first learn to identify this group of stars? Although they are familiar to many people around the world, different cultures have associated this asterism with different icons and folklore. Known...

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.