SIRTF: Name This Satellite
19.09.2001

NASA is preparing to launch its next Great Observatory in 2002, but it does not yet have a proper name. Can you help? Currently referred to only as the Space Infrared Telescope Facility (SIRTF), NASA seeks to add something more significant.

Jupiter, Moons, and Bees
25.09.2002

Rising before the Sun on September 4, Jupiter and an old cresent Moon gathered in the dim constellation of Cancer. Watching from a hillside near Austin, Texas, planet Earth, astrophotographer Russell Croman recorded this view of their passing as clouds gracefully dimmed the brilliant moonlight.

Crossing The Ring Plane
1.08.1995

"I do not know what to say in a case so surprising, so unlooked for and so novel." announced Galileo when Saturn's rings appeared to vanish in 1612. In fact, every 15 years Saturn's rings seem to almost disappear as viewed from the Earth.

Red Sun Streaming
6.01.1997

The Sun is leaking. In fact, it is gushing: particles stream away from the Sun at hundreds of kilometers per second. Some of these particles strike the Earth and cause aurora. Most particles, however, either surround the Sun as a huge solar corona or glide into interstellar space as the solar wind.

Moving Echoes Around SN 1987A
24.10.1997

Yesterday's image highlighted reflective rings of light emitted by a supernova explosion. Today's pictures, taken over a year apart, highlight how these echoes are seen to move over time. Visible...

Dusting Spiral Galaxies
15.01.1998

How much dust is in spiral galaxies? Does it block out much of the starlight? Because astronomers rely on an accurate knowledge of galaxy properties to investigate a wide range of problems, like galaxy and quasar evolution and the nature of dark matter, answers to simple questions like this are key.

Exploring Saturn's Rings
31.07.1995

By watching a star flicker and fade as it passed behind Saturn's rings, NASA's Voyager 2 spacecraft was able explore the ring system in amazing detail. Data produced by Voyager's instruments...

Orion Star Colours
29.08.1998

What determines a star's colour? Its temperature. Red stars are cool, around 3,000 kelvins (K), while blue stars are hotter and can have temperatures over 30,000 K. Our own lovely yellow Sun's temperature is a comforting 6,000 K.

Attacking Mars
19.07.2004

The Spirit rover attacked Mars again late last month. What might look, above, like a military attack, though, was once again just a scientific one - Spirit was instructed to closely inspect some interesting rocks near Columbia Hills.

Moon Occults Saturn
8.05.1999

On September 18, 1997, many stargazers in the U. S. were able to watch a lovely early morning lunar occultation as a bright Moon passed in front of Saturn. Using a 1.2 meter reflector, astronomer Kris Stanek had an excellent view of this dream-like event from the Whipple Observatory atop Arizona's Mount Hopkins.