NGC 1818: Pick A Star
31.05.2003

This is NGC 1818, a youthful, glittering cluster of 20,000 stars residing in the Large Magellanic Cloud, 180,000 light-years away. Pick a star. Any star. Astronomers might pick the unassuming bluish-white one (circled) which appears to be a hot newly formed white dwarf star. What makes it so interesting?

Unexpected Galaxy String in the Early Universe
20.01.2004

How could such a long string of galaxies form so early in the universe? Several new measurements of galaxies and clusters in the early universe are reporting structures involving galaxies and clusters that are larger than expected with the new standard "dark-energy" cosmology.

COBE Hotspots: The Oldest Structures Known
7.02.1998

Above is a microwave image of the entire sky. The plane of our galaxy runs horizontally through the center. This historic all-sky map is based on the first two years of data from NASA's COsmic Background Explorer (COBE) satellite.

V838 Light Echo: The Movie
2.04.2003

What caused this outburst of V838 Mon? For reasons unknown, star V838 Mon's outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy. Then, just as suddenly, it faded.

Denizen of the Tarantula Nebula
3.05.2003

The star cluster at lower right, cataloged as Hodge 301, is a denizen of the Tarantula Nebula. An evocative nebula in the southern sky, the sprawling cosmic Tarantula is an energetic star forming region some 168,000 light-years distant in our neighboring galaxy the Large Magellanic Cloud.

Saturnian Aurora
9.01.1998

Girdling the second largest planet in the Solar System, Saturn's Rings are one of the most spectacular sights for earthbound telescopes. This recently released image, from the orbiting Hubble Space Telescope's STIS instrument, offers a striking view of another kind of ring around Saturn - pole encircling rings of ultraviolet aurora.

Cone Nebula Close Up
29.05.2004

Cones, pillars, and majestic flowing shapes abound in stellar nurseries where natal clouds of gas and dust are buffeted by energetic winds from newborn stars. A well-known example, the Cone Nebula within the bright galactic star-forming region NGC 2264, was captured in this close-up view from the Hubble Space Telescope's Advanced Camera for Surveys.

APOD: 2004 August 26- Cassiopeia A in a Million
26.08.2004

One million seconds of x-ray image data were used to construct this view of supernova remnant Cassiopeia A, the expanding debris cloud from a stellar explosion. The stunningly detailed image from the Chandra Observatory will allow an unprecedented exploration of the catastrophic fate that awaits stars much more massive than the Sun.

Eight Kilometers Above Titan
19.01.2005

What are these surface features on Titan? Scroll right to see the panoramic view captured last week by the Huygens probe as it descended toward Saturn's mysterious moon. Scientists are not yet sure what the above image is showing.

Gravity Probe B Confirms the Existence of Gravitomagnetism
10.05.2011

Does gravity have a magnetic counterpart? Spin any electric charge and you get a magnetic field. Spin any mass and, according to Einstein, you should get a very slight effect that acts something like magnetism. This effect is expected to be so small that it is beyond practical experience and ground laboratory measurement.