Lightning on Earth
17.07.2000

Nobody knows what causes lightning. It is known that charges slowly separate in some clouds causing rapid electrical discharges (lightning), but how electrical charges get separated in clouds remains a topic of much research.

Globular Cluster M3
19.07.1998

This huge ball of stars predates our Sun. Long before mankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy.

Teide Sky Trails
12.02.2010

The snow capped Teide volcano is reflected in a pool of water in this nearly symmetric night sky view from the Canary Island Tenerife. Bright north star Polaris stands above the peak in an exposure that also captures the brilliant trail of a polar orbiting Iridium satellite.

Aurora Australis
4.07.2015

Not fireworks, these intense shimmering lights still danced across Earth's night skies late last month, seen here above the planet's geographic south pole. The stunning auroral displays were triggered as a coronal mass ejection blasted from the Sun days earlier impacted the magnetosphere, beginning a widespread geomagnetic storm.

August Lunar Eclipse
9.08.2017

August's Full Moon is framed in this sharp, high dynamic range composition. Captured before sunrise on August 8 from Sydney, Australia, south is up and the Earth's dark, umbral shadow is at the left, near the maximum phase of a partial lunar eclipse.

Star Trails in Southern Skies
15.07.2000

As the Earth spins on its axis, the stars seem to rotate around us. This motion produces the beautiful concentric arcs traced out by the stars in this time exposure of the southern hemisphere night sky. In the foreground is the dome of the Anglo-Australian Telescope in central New South Wales, Australia.

The Coma Cluster of Galaxies
21.03.2006

Almost every object in the above photograph is a galaxy. The Coma Cluster of Galaxies pictured above is one of the densest clusters known - it contains thousands of galaxies. Each of these galaxies houses billions of stars - just as our own Milky Way Galaxy does.

A Fire Rainbow Over New Jersey
10.06.2008

What is that inverted rainbow in the sky? Sometimes known as a fire rainbow for its flame-like appearance, a circumhorizon arc is created by ice, not fire. For a circumhorizon arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds are present.

Irregular Galaxy Sextans A
14.11.1997

Grand spiral galaxies often seem to get all the glory. Their newly formed, bright, blue star clusters found along beautiful, symmetric spiral arms are guaranteed to attract attention. But small irregular galaxies form stars too, like this lovely, gumdrop-shaped galaxy, Sextans A.

Erupting Sun
18.09.1997

On August 27th twisting magnetic fields propelled this huge eruptive prominence a hundred thousand miles above the Sun's surface. The seething plasma of ionized gases is at a temperature of about 150,000 degrees Farenheit and spans over 200,000 miles (about 27 Earths).