Solar Shock Wave
On September 24, 1997 a shock wave blasted across the surface of the sun at speeds of 250 to 600 kilometers per second. On planet Earth, observer Barry Reynolds photographed the expanding shock front (left) in the light emitted by hydrogen atoms ...
NGC 2266: Old Cluster in the New...
The New General Catalog of star clusters and nebulae really isn't so new. In fact, it was published in 1888 - an attempt by J. L. E. Dreyer to consolidate the work of astronomers William, Caroline, and John Herschel along with others into a ...
A Sundial for Mars
When Mars Surveyor arrives at Mars in 2002, it will carry a sundial. Even though batteries and a solar array will power the Mars Surveyor Lander, the sundial has been included to allow a prominent public display of time. The sundial idea was the ...
Introducing Comet Lee
Another large snowball is falling toward the Sun. Comet Lee was discovered two weeks ago by Steve Lee (AAO) in Australia, and is expected to brighten as it approaches the inner Solar System. Comet Lee is not expected to become a naked-eye ...
USNO-A2.0 Catalog: A Digital Sky
Here lie 526,230,881 of the brightest stars known. The US Naval Observatory has deployed their monster Precision Measuring Machine to digitize photographic plates covering the whole sky and creating the above map. Yellow corresponds to 150,000 ...
Mimas: Small Moon with a Big Crater
Mimas is one of the smaller moons of Saturn but shows one of the largest impact craters. In fact, if the impact had been much greater, it would have disrupted the entire satellite. The large crater has been named Herschel after the 1789 ...
Barsoom
"Yes, I have been to Barsoom again ..." begins John Carter in Edgar Rice Burroughs' 1913 science fiction classic "The Gods of Mars". In Burroughs' novels describing Carter's adventures on Mars, "Barsoom" is the local inhabitants' name for the Red ...
Io Shadow
Orbiting Jupiter once every 43 hours, the volcanic moon Io cruises 500,000 kilometers above swirling, banded cloud-tops. Orbiting Earth once every 1.5 hours, the Hubble Space Telescope watched as Io accompanied by its shadow crossed the face of ...
Where is Upsilon Andromedae?
Astronomers recently announced the detection of three large planets orbiting the star Upsilon Andromedae - the first planetary system known to orbit a normal star other than our Sun. These planets were not directly photographed but found through ...
The Nearest Stars
Which stars are closest to the Sun? The closest is Proxima Centauri, one of three stars that orbit each other about 4 light-years away in the Alpha-Centauri system. Alpha Centauri is easily visible from Earth's Southern Hemisphere. Next is ...
