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...

Why Stars Twinkle
25.07.2000

This is what a star really looks like from the surface of the Earth. To the best the human eye can see, stars are so far away they appear the same as would infinitesimal points of light.

New Stars Destroying NGC 1748
3.04.2001

NGC 1748 cannot contain all the new stars it has formed. The young stars, the most massive of which are bright blue, emit so much energy they are pushing out and dispersing the gas and dust that comprise this star forming nebula.

M2 9: Wings of a Butterfly Nebula
17.12.2000

Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured above

The Perseus Cluster of Galaxies
5.04.1996

Here is one of the largest objects that anyone will ever see on the sky. Each of the fuzzy blobs in the above picture is a galaxy, together making up the Perseus Cluster, one of the closest clusters of galaxies.

Saturn at Night
12.09.2006

This is what Saturn looks like at night. In contrast to the human-made lights that cause the nighttime side of Earth to glow faintly, Saturn's faint nighttime glow is primarily caused by sunlight reflecting off of its own majestic rings.

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.

Camera Orion
15.10.2008

Orion, the Hunter, is one of the most easily recognizable constellations in planet Earth's night sky. But Orion's stars and nebulas don't look quite as colorful to the eye as they...

Possible Jet Blown Shells Near Microquasar Cygnus X1
8.06.2009

What happens to matter that falls toward an energetic black hole? In the case of Cygnus X-1, perhaps little of that matter actually makes it in. Infalling gas may first collide not only with itself but with an accretion disk of swirling material surrounding the black hole.

A Fading Moonset Over Hong Kong
15.12.2009

Do stars appear dimmer when nearer the horizon? Yes -- atmospheric air absorbs and reradiates light, so that the greater the airmass through which one peers, the fainter an object will appear. Pictured above in a multi-frame image, stars, the planet Jupiter, and even the Moon show the horizon-dimming effects of Earth's nearly-transparent atmosphere.