APOD: 2023 December 20 Б Ice Halos over Bavaria
20.12.2023

What's causing those unusual sky arcs? Ice crystals. While crossing a field of fresh snow near Fцssen, Bavaria, Germany, earlier this month, the photographer noticed that he had entered an ice fog.

APOD: 2025 August 31 Б NGC 7027: The Pillow Planetary Nebula
31.08.2025

What created this unusual planetary nebula? Dubbed the Pillow Nebula and the Flying Carpet Nebula, NGC 7027 is one of the smallest, brightest, and most unusually shaped planetary nebulas known. Given its expansion rate, NGC 7027 first started expanding, as visible from Earth, about 600 years ago.

Slightly Above Mars Pathfinder
12.09.2000

If you could have hovered above the Pathfinder mission to Mars in 1997, this is what you might have seen. Directly below you is the control tower of Sagan Memorial Station. Three dark solar...

NGC 4631: The Whale Galaxy
23.01.2004

NGC 4631 is a big beautiful spiral galaxy seen edge-on only 25 million light-years away towards the small northern constellation Canes Venatici. This galaxy's slightly distorted wedge shape suggests to some a cosmic herring and to others the popular moniker of The Whale Galaxy.

A Meteor Shower Fireball Movie
12.08.2005

Go outside tonight and see a celestial light show -- the later the better. Tonight is the peak of the month-long Perseid Meteor Shower. Although visible every year at this time, the Perseids are expected to appear particularly active this year due to the relative absence of glare from the Moon during the peak.

GLIMPSE the Milky Way
16.12.2005

Scroll right and gaze through the dusty plane of our Milky Way Galaxy in infrared light. The cosmic panorama is courtesy of the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) project and the Spitzer Space Telescope.

The Double Ring Galaxies of Arp 147 from Hubble
4.11.2008

How could a galaxy become shaped like a ring? Even more strange: how could two? The rim of the blue galaxy pictured on the right shows an immense ring-like structure 30,000 light years in diameter composed of newly formed, extremely bright, massive stars.

Bright Planets at McMath Pierce Solar Telescope
16.03.2012

Bright planets Venus and Jupiter are framed by the National Solar Observatory's McMath-Pierce Solar Telescope in this very astronomical scene. The photo was taken at Kitt Peak National Observatory on March 9.

The Sun in X rays from NuSTAR
28.12.2014

Why are the regions above sunspots so hot? Sunspots themselves are a bit cooler than the surrounding solar surface because the magnetic fields that create them reduce convective heating. It is therefore unusual that regions overhead -- even much higher up in the Sun's corona -- can be hundreds of times hotter.

Planetary Nebula Mz3: The Ant Nebula
26.04.2015

Why isn't this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not round?