The Southern Cross in a Southern Sky
7.07.2008

This breathtaking patch of sky would be above you were you to stand at the South Pole of the Earth. On the upper left of this image are the four stars that mark the boundaries of the famous Southern Cross.

Globular Cluster M15
10.12.2001

Stars, like bees, swarm around the center of bright globular cluster M15. This ball of over 100,000 stars is a relic from the early years of our Galaxy, and continues to orbit the Milky Way's center.

M13: The Great Globular Cluster in Hercules
18.05.2007

In 1714, Edmond Halley noted that M13 "shows itself to the naked eye when the sky is serene and the Moon absent." Of course, M13 is now modestly recognized as the Great Globular Cluster in Hercules, one of the brightest globular star clusters in the northern sky.

The Extraordinary Spiral in LL Pegasi
29.11.2021

What created the strange spiral structure on the upper left? No one is sure, although it is likely related to a star in a binary star system entering the planetary nebula phase, when its outer atmosphere is ejected.

The 37 Cluster
14.05.2024

For the mostly harmless denizens of planet Earth, the brighter stars of open cluster NGC 2169 seem to form a cosmic 37. Did you expect 42? From our perspective, the improbable numerical asterism appears solely by chance. It lies at an estimated distance of 3,300 light-years toward the constellation Orion.

APOD: 2026 April 7 Б IC 4592: The Blue Horsehead Reflection Nebula
7.04.2026

Do you see the horse's head? What you are seeing is not the famous Horsehead nebula toward Orion, but rather a fainter nebula that only takes on a familiar form with deeper imaging. The main part of the here-imaged molecular cloud complex is reflection nebula IC 4592.

Dawn Before Nova
17.11.2009

Will this dawn bring another nova? Such dilemmas might be pondered one day by future humans living on a planet orbiting a cataclysmic variable binary star system. Cataclysmic variables involve gas falling from a large star onto an accretion disk surrounding a massive but compact white dwarf star.

Southern Cross in Mauna Loa Skies
29.01.2005

Gazing across this gorgeous skyscape, the Southern Cross and stars of the constellation Centaurus are seen above the outline of Mauna Loa (Long Mountain), planet Earth's largest volcano. Unfamiliar to sky gazers north...

APOD: 2025 April 28 Б Gum 37 and the Southern Tadpoles
28.04.2025

This cosmic skyscape features glowing gas and dark dust clouds alongside the young stars of NGC 3572. A beautiful emission nebula and star cluster, it sails far southern skies within the nautical constellation Carina.

NGC 7009: The Saturn Nebula
30.12.1997

The layers of the Saturn Nebula give a complex picture of how this planetary nebula was created. The above picture, taken in April 1996 and released last week, allows a better understanding of the mysterious process that transformed a low-mass star into a white dwarf star.