Alpha Centauri: The Closest Star System
26.05.1996

The closest star system to the Sun is the Alpha Centauri system. Of the three stars in the system, the dimmest -- called Proxima Centauri -- is actually the nearest star. The bright stars Alpha Centauri...

VDB 142 in Cepheus
11.10.2001

A gorgeous collection of dust and gas nebulae in the Northern Milky Way graces the high and far off constellation of Cepheus. With colors based on astronomical filters, this close up of the region highlights stars embedded in curiously shaped cosmic clouds.

A Year of Dark Cosmology
31.12.2001

We live in the exciting time when humanity discovers the nature of our entire universe. During this year, in particular, however, the quest for cosmological understanding appears to have astronomers groping in the dark.

The Clouds of Neptune
7.05.1996

These Hubble Space Telescope (HST) images reveal glimpses of the dynamic atmosphere of Neptune, the Solar System's most distant gas giant planet. The first close-up of Neptune's clouds was provided by NASA's Voyager 2 spacecraft during its August 1989 flyby, giving a tantalizingly brief look.

M57: The Ring Nebula
4.07.2004

Except for the rings of Saturn, the Ring Nebula (M57) is probably the most famous celestial band. This planetary nebula's simple, graceful appearance is thought to be due to perspective -- our view from planet Earth looking straight into what is actually a barrel-shaped cloud of gas shrugged off by a dying central star.

The Case of the Missing Supernova
13.04.1999

Would you notice a second Moon in the sky? About 700 years ago, light from a tremendous explosion reached Earth that should have appeared almost as bright as a full Moon. The bright spot should have lasted for weeks, yet no notation of such an occurrence has been found in historical records.

The Solar Spectrum
23.04.2006

It is still not known why the Sun's light is missing some colors. Shown above are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device.

The Local Interstellar Cloud
11.04.2000

The stars are not alone. In the disk of our Milky Way Galaxy about 10 percent of visible matter is in the form of gas, called the interstellar medium (ISM). The ISM is not uniform, and shows patchiness even near our Sun.

Galaxies Away
21.08.1999

This striking pair of galaxies is far, far away ... about 350 million light-years from Earth. Cataloged as AM0500-620, the pair is located in the southern constellation Dorado. The background elliptical and foreground spiral galaxy are representative of two of the three major classes of galaxies which inhabit our Universe.

Could Hydrogen Peroxide Life Survive on Mars
28.08.2007

Is there life on Mars? Although no unambiguous evidence for indigenous life on Mars has ever been found, a more speculative question -- could some life forms survive on Mars -- has taken on a new twist.