Anticrepuscular Rays Over Colorado
16.11.2008

What's happening over the horizon? Although the scene may appear somehow supernatural, nothing more unusual is occurring than a setting Sun and some well placed clouds. Pictured above are anticrepuscular rays. To understand them, start by picturing common crepuscular rays that are seen any time that sunlight pours though scattered clouds.

In Green Company: Aurora over Norway
10.12.2017

Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds -- mostly. On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a spectacular auroral display.

Mid Eclipse and Milky Way
27.05.2021

May's perigee Full Moon slid through Earth's shadow yesterday entertaining night skygazers in regions around the Pacific. Seen from western North America, it sinks toward the rugged Sierra Nevada mountain range in this time-lapse series of the total lunar eclipse.

Pluto in True Color
19.03.2001

Pluto is mostly brown. The above picture captures the true colors of Pluto as well as the highest surface resolution so far recovered. No spacecraft has yet visited this most distant planet in our Solar System.

Moonrise Over Seattle
30.01.2002

Is the Moon larger when near the horizon? No -- as shown above, the Moon appears to be very nearly the same size no matter its location on the sky. Oddly, the cause or causes for the common Moon Illusion are still being debated.

The Sun Today
18.05.1996

Our Sun shows a different face every day. The above picture was taken on May 15, but a similar picture of the Sun actually taken today can be found here. The above picture was taken in red light and so is shown in red.

M101: An Ultraviolet View
8.06.1997

This giant spiral galaxy, Messier 101 (M101), was photographed by the Ultraviolet Imaging Telescope (UIT). UIT flew into orbit as part of the Astro 2 mission on-board the Space Shuttle Endeavour in March 1995. The image has been processed so that the colors (purple to white) represent an increasing intensity of ultraviolet light.

Henize 70: A SuperBubble In The LMC
13.06.1998

Stars with tens of times the mass of the Sun profoundly affect their galactic environment. Churning and mixing the interstellar gas and dust clouds they leave their mark in the compositions and locations of future generations of stars and star systems.

Phases of Venus
21.05.2004

Venus is currently falling out of the western evening sky. Second planet from the Sun and third brightest celestial object after the Sun and Moon, Venus has been appreciated by casual sky gazers as a brilliant beacon above the horizon after sunset. But telescopic images have also revealed its dramatic phases.

Light from the Heart Nebula
3.10.2006

What powers the Heart Nebula? The large emission nebula dubbed IC 1805 looks, in whole, like a human heart. The nebula glows brightly in red light emitted by its most prominent element: hydrogen. The red glow and the larger shape are all created by a small group of stars near the nebula's center.