Leonids Over Monument Valley
15.11.2015

There was a shower over Monument Valley -- but not water. Meteors. The featured image -- actually a composite of six exposures of about 30 seconds each -- was taken in 2001, a year when there was a very active Leonids shower.

Arp 81: 100 Million Years Later
11.12.2003

From planet Earth, we view this strongly interacting pair of galaxies, cataloged as Arp 81, as they were only about 100 million years after their mutual closest approach. The havoc wreaked by gravity during...

NGC 6888: A Tricolor Starfield
6.07.2006

NGC 6888, also known as the Crescent Nebula, is a cosmic bubble about 25 light-years across, blown by winds from its central, bright, massive star. Near the center of this intriguing widefield view of interstellar gas clouds and rich star fields of the constellation Cygnus, NGC 6888 is about 5,000 light-years away.

Aurorae on Jupiter
11.07.2016

Jupiter has aurorae. Like Earth, the magnetic field of the gas giant funnels charged particles released from the Sun onto the poles. As these particles strike the atmosphere, electrons are temporarily knocked away from existing gas molecules. Electric force attracts these electrons back. As the electrons recombine to remake neutral molecules, auroral light is emitted.

Z is for Mars
22.04.2006

This composite of images spaced about a week apart - from late July 2005 (bottom right) through February 2006 (top left) - traces the retrograde motion of ruddy-colored Mars through planet Earth's night sky. On November 7th, 2005 the Red Planet was opposite the Sun in Earth's sky (at opposition).

Solar Flare from a Sharper Sun
21.11.2014

Solar active region AR2192 was the largest recorded sunspot group of the last 24 years. Before rotating off the Earth-facing side of the Sun at the end of October, it produced a whopping six energetic X-class flares.

The Crab Nebula Pulsar Shrugs
20.09.2002

How does a city-sized neutron star power the vast Crab Nebula? The expulsion of wisps of hot gas at high speeds appears to be at least part of the answer. Yesterday time-lapse movies taken...

Portrait of NGC 281
25.08.2011

Look through the cosmic cloud cataloged as NGC 281 and it's almost easy to miss stars of open cluster IC 1590. But, formed within the nebula, that cluster's young, massive stars ultimately power the pervasive nebular glow.

NGC 6822: Barnard s Galaxy
8.02.2013

Grand spiral galaxies often seem to get all the glory, flaunting their young, bright, blue star clusters in beautiful, symmetric spiral arms. But small galaxies form stars too, like nearby NGC 6822, also known as Barnard's Galaxy.

The Large Cloud of Magellan
28.05.2013

The 16th century Portuguese navigator Ferdinand Magellan and his crew had plenty of time to study the southern sky during the first circumnavigation of planet Earth. As a result, two fuzzy cloud-like objects easily...