The Tarantula Nebula
6.01.2006

First cataloged as a star, 30 Doradus is actually an immense star forming region in nearby galaxy The Large Magellanic Cloud. The region's spidery appearance is responsible for its popular name, the Tarantula Nebula, except that this tarantula is about 1,000 light-years across, and 180,000 light-years away in the southern constellation Dorado.

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).

M82: Starburst in X-rays
21.04.2000

Star formation occurs at a faster pace in M82 -- a galaxy with about 10 times the rate of massive star birth (and death) compared to our Milky Way. Winds from massive stars and blasts...

Accretion Disk Binary System
19.12.1999

Our Sun is unusual in that it is alone - most stars occur in multiple or binary systems. In a binary system, the higher mass star will evolve faster and will eventually become a compact object - either a white dwarf star, a neutron star, or black hole.

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.

An Extraordinary Spiral from LL Pegasi
14.09.2010

What created the strange spiral structure on the left? No one is sure, although it is likely related to a star in a binary star system entering the planetary nebula phase, when its outer atmosphere is ejected.

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.

Atoms for Peace Galaxy Collision
16.11.2010

Is this what will become of our Milky Way Galaxy? Perhaps if we collide with the Andromeda Galaxy in a few billion years, it might. Pictured above is NGC 7252, a jumble of stars created by a huge collision between two large galaxies.

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.

Moon Over Andromeda
1.08.2013

The Great Spiral Galaxy in Andromeda (aka M31), a mere 2.5 million light-years distant, is the closest large spiral to our own Milky Way. Andromeda is visible to the unaided eye as a small...