Astronomy Picture of the Day

1999-09-17

This immense ball of half a million stars older than the sun lies 30,000 light-years above the plane of our Galaxy. Cataloged as M3 (and NGC 5272), it is one of about 250 globular star clusters which roam our galactic halo. Individual stars are ...

1999-09-16

Watch closely. As this animation blinks between two Hubble Space Telescope images of NGC 6543 - the first from 1994 and the second from 1997 - the intricate filaments of this nebula are seen to shift. The shift is due to the actual expansion of ...

1999-09-15 Fred Espenak

Most photographs don't adequately portray the magnificence of the Sun's corona. Seeing the corona first-hand during a total solar eclipse is best. The human eye can adapt to see features and extent that photographic film usually cannot. ...

1999-09-13

Thousands of years after a star explodes, an expanding remnant may still glow brightly. Such is the case with N132D, a supernova remnant located in the neighboring Large Magellanic Cloud galaxy. The expanding shell from this explosion now spans ...

1999-09-12 Clive Ruggles

Stonehenge consists of large carved stones assembled about 4000 years ago. Long before modern England was established, ancient inhabitants somehow moved 25 ton rocks nearly 20 miles to complete it. From similar constructs of the era, people ...

1999-09-11

The sky toward the center of our Galaxy is filled with a wide variety of celestial wonders. Many are easily visible with binoculars. Constellations near the galactic center include Sagittarius, Libra, Scorpius, Scutum, and Ophiuchus. Nebulae ...

1999-09-10

On August 18, the Cassini spacecraft flew by the Earth and Moon, then continued on its way to the outer solar system. Near its closest approach to the Moon, a distance of about 377,000 kilometers, controllers tested Cassini's imaging systems on ...

1999-09-09 William R. Dellinges

Four years ago, Comet Hale-Bopp was discovered out near Jupiter falling toward the inner Solar System. Two years ago, it provided spectacular pictures as it neared its closest approach to the Sun. Still today, spectacular pictures of the ...

1999-09-08

In astronomical parlance, an interior planet is at superior conjunction when it is located on the opposite side of the Sun from Earth. Mercury, the solar system's innermost planet, zips past this point in its orbit today. In fact, this recent ...

1999-09-07

What would you do if it rained blue water from space? On 1998 March 22, no umbrella was needed, as the blue water came attached to a stony meteorite that landed in Monahans, Texas. The meteorite fall was seen by several boys, and was being ...