Helios Helium
16.05.1998

This image of the relatively quiet Sun was made using ultraviolet light emitted by ionized Helium atoms in the Solar chromosphere. Helium was first discovered in the Sun in 1868, its name fittingly derived from from the Greek word Helios, meaning Sun.

NGC 4676: When Mice Collide
12.06.2004

These two mighty galaxies are pulling each other apart. Known as "The Mice" because they have such long tails, each spiral galaxy has likely already passed through the other. They will probably collide again and again until they coalesce.

The Galaxy Within Centaurus A
4.03.2006

Peering deep inside Centaurus A, the closest active galaxy to Earth, the Spitzer Space Telescope's penetrating infrared cameras recorded this startling vista in February 2004. About 1,000 light-years across, the twisted cosmic...

Rings Around Beta Pictoris
8.02.2000

An unusual dust disk surrounds nearby star Beta Pictoris. Discovered in 1983, astronomers are still learning just how unusual this disk is. Recent images and computer simulations indicate that the disk contains several elliptical dust rings larger than our own Solar System.

The Incredible Expanding Cats Eye
16.09.1999

Watch closely. As this animation blinks between two Hubble Space Telescope images of NGC 6543 - the first from 1994 and the second from 1997 - the intricate filaments of this nebula are seen to shift. The shift is due to the actual expansion of this gaseous shroud shed by a dying star!

Orion s Cradle
25.01.2007

Cradled in glowing hydrogen, stellar nurseries in Orion lie at the edge of a giant molecular cloud some 1,500 light-years away. This breath-taking view spans about 13 degrees across the center of the well-known constellation with the Great Orion Nebula, the closest large star forming region, just right of center.

APOD: 2007 February 24- X rays and the Eagle Nebula
24.02.2007

The premier Chandra X-ray Observatory images of M16, the Eagle Nebula, show many bright x-ray sources in the region. Most of the x-ray sources are energetic young stars. They are seen here as colored spots superimposed on the Hubble's well-known optical view of M16's light-year long Pillars of Creation.

Running Messier s Marathon
19.04.2008

Gripped by an astronomical spring fever, many northern hemisphere stargazers embark on a Messier Marathon. Completing the marathon requires viewing all 110 objects in 18th century French astronomer Charles Messier's catalog in one glorious dusk-to-dawn observing run.

Equinox and the Iron Sun
23.09.2010

Today, the Sun crosses the celestial equator heading south at 03:09 Universal Time. Known as an equinox, this astronomical event marks the first day of autumn in the northern hemisphere and spring in the south. Equinox means equal night.

Geometers Playground Over Wyoming
6.06.2011

If you travel several kilometers off a main highway through Wyoming, you may see an unusual sight. In particular, near Buford, Wyoming, USA, you could run across the geometric Ames Monument, visible on the right, built to commemorate the financiers of a historic transcontinental railroad across North America.