Astronomy Picture Of the Day (APOD)5 Million Miles From Io
Twenty years ago this month, NASA's Voyager 1 spacecraft flew past Jupiter and its moons. This sharp picture of moon Io against a background of gas giant Jupiter's diffuse swirling cloud bands was recorded by Voyager's camera from a distance of about 5 million miles.
NGC 2997 from VLT
Add another 8-meter telescope to the list of modern optical telescope giants. Kueyen achieved a first-light photograph of a bright star on March 1, ahead of schedule. The above picture of spiral galaxy...
The VLT Interferometric Array
The Very Large Telescope (VLT) Interferometric Array will be able to act as individual telescopes or as one huge telescope. Of the four planned VLTs in Chile, two have now reached completion. The first VLT to operate is visible on the left of the above photograph and was recently given the name Antu.
A Jupiter Venus Conjunction
Venus and Jupiter appeared unusually close together in the sky last month. The conjunction was easily visible to the unaided eye because Venus appears brighter than any background star. The two planets were not significantly closer in space - Venus just passed nearly in front of Jupiter as seen from the Earth.
Tychos Supernova Remnant in X ray
How often do stars explode? By looking at external galaxies, astronomers can guess that these events, known as a supernovae, should occur about once every 30 years in a typical spiral galaxy like our MilkyWay.
Miranda, Chevron, and Alonso
Miranda is a bizarre world which surely had a tempestuous past. The innermost of the larger Uranian moons, Miranda is almost 300 miles in diameter and was discovered in 1948 by American planetary astronomer Gerard Kuiper.
M46 And NGC 2438: Young And Old
Galactic or open star clusters are relatively young. These swarms of bright stars are born near the plane of the Milky Way, but their numbers steadily dwindle as cluster members are strewn through the Galaxy by gravitational interactions.
Ganymede, one of the four Galilean moons of Jupiter, is the largest moon in the Solar System. With a diameter of 5,260 kilometers it is even larger than planets Mercury and Pluto and just over three quarters the size of Mars. Ganymede is locked in synchronous rotation with Jupiter.
Was Mars wetter and more Earth-like in its distant past? This false-color composite image of Mars is part of the mounting evidence that liquid water once did play a significant role in Martian surface geology.
The Kleinmann Low Nebula
The most active part of the Orion Nebular Cloud Complex is an area known as the Kleinmann-Low Nebula. There, a cluster of young and forming stars is embedded in a molecular cloud filled with dust.