Astronomy Picture of the Day

1998-04-23

These separate radio images reveal three dusty debris disks surrounding three bright, young, nearby stars - evidence for solar systems in formation. From left to right are the stars Fomalhaut, Beta Pictoris, and Vega, their positions indicated by ...

1998-04-22

Two hundred and twenty light years from Earth, planets are forming. Recent observations of the binary star system HR 4796 have shown that one of the stars is surrounded by a dusty gaseous disk. This disk is of the right size, age, and density ...

1998-04-21

Is Orion all wet? Recent observations have confirmed that water molecules now exist in the famous Orion Nebula, and are still forming. The Orion Nebula (M42, shown above) is known to be composed mostly of hydrogen gas, with all other atoms and ...

1998-04-20

Can you name this satellite? In December, NASA's third Great Observatory is planned for launch. The two NASA Great Observatories currently in orbit are the Hubble Space Telescope and the Compton Gamma-Ray Observatory, both now named for famous ...

1998-04-19

Here is the first direct picture of the surface of a star other than our Sun. Taken by the Hubble Space Telescope in 1995, the atmosphere of Betelgeuse reveals some unexpected features, including a large bright hotspot visible below the center. ...

1998-04-18

Long ago in a galaxy far, far away, locked in their final desperate struggle against the force of gravity ... two stars exploded! stellar explosions - Supernovae - are among the most powerful events in the Universe, estimated to release an ...

1998-04-17

On July 20, 1976, the Viking 1 lander touched down on the Martian Chryse Planitia. Its exact landing site is somewhere in the white rectangle above. Unfortunately, this wide angle Mars Global Surveyor image taken on April 12 reveals a substantial ...

1998-04-16

The Mars Global Surveyor spacecraft has returned another close-up of the Cydonia region on Mars. Orbiting over clear Martian skies at a range of about 200 miles, the Mars Orbiter Camera looked down on features known as the "City" on Mars and ...

1998-04-15

This is NGC 1818, a youthful, glittering cluster of 20,000 stars residing in the Large Magellanic Cloud, 164,000 light-years away. Pick a star. Any star. Astronomers might pick the unassuming bluish-white one (circled) which appears to be a hot ...

1998-04-14 G. Greaney

Wisps of dust fill the space between the stars. This dust is usually invisible, subtly acting to dim the light of more distant stars. Sometimes this dust is thick and prominent as dark patches on otherwise bright emission nebulae. Other times ...