Join our SkyWatch hosts for a weekly conversation that highlights news from the world of astronomy. Listen in via your computer or MP3 player as they bring the latest discoveries down to Earth. SkyWatch also includes HubbleWatch, a monthly round-up of news from NASA’s Hubble Space Telescope.
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September 11, 2008
Show 181: Clusters in a Cluster
About 54 million light-years from Earth, roughly 2,000 galaxies have ganged up in a gravitational grouping called the Virgo Cluster. Centering that cluster is a massive galaxy that is itself surrounded by many clusters-in this case, star clusters. But this massive galaxy has more of these star clusters than astronomers expected it to have. Could it be stealing from its neighbors?
September 4, 2008
Show 180: Hubble Hits 100,000 Orbits
In August, the Hubble Space Telescope completed its 100,000th orbit around Earth. Understandably, the venerable observatory is due for a little maintenance. In October, astronauts will be returning to Hubble to install two new science instruments, repair two other instruments, and upgrade other critical components on the telescope.
August 28, 2008
Show 179: HubbleWatch for August 2008
Hubble celebrated a new milestone in August – 100,000 orbits around the planet Earth. Scientists think they know why a certain galaxy has more globular clusters than its neighbors. And a black hole-inhabited galaxy is sending tendrils into the universe.
August 28, 2008
Show 178: Cassini and the Jets
The Cassini spacecraft performed a daring flyby of Saturn’s moon Enceladus on March 12, flying about 15 kilometers per second (32,000 mph) through a geyser-like jet spurting from the moon’s surface. It captured sample molecules from the jet.
In August, it used special techniques to get pictures of the jets. Scientists want to know where the jets come from and whether Enceladus has water.
August 21, 2008
Show 177: Water from a Rock
Could Earth’s Moon have water locked up inside its rocks? Samples brought back from the Apollo Moon mission may indicate that the answer is yes. Water may be locked up in volcanic glass beads within the rocks.
August 14, 2008
Show 176: Giant Lurks in Kuiper Belt?
The Kuiper Belt is a region past Neptune, full of icy, comet-like objects. Pluto is the most famous Kuiper Belt object. Some of these objects have odd orbits that don’t fit with our knowledge of the solar system. A computer model suggests that the region may contain a really large body — 30 to 70 percent as massive as Earth — that affects the orbits of objects around it.
August 7, 2008
Show 175: New Moon?
The Moon may be younger than originally thought – by about 30 million years. The Moon is thought to have formed after an object hit the Earth, partially melting the planet and propelling material into space. Because the Earth and Moon formed around the same time, this also brings up questions about our planet’s formation.
July 31, 2008
Show 174: Two for the Price of One
The Lincoln Near-Earth Asteroid Research (LINEAR) project scans the skies for asteroids in an attempt to find 90% of all the asteroids larger than 0.6 mile (1 km) in diameter by the end of 2008. In January 2008, LINEAR found an object now called Asteroid 2008 BT18. Original calculations suggested the asteroid was going to pass nearby the earth. Asteroid orbits can be altered by the Earth’s gravity, so the trajectory was uncertain. Luckily the object passed almost six times the distance between the Earth and Moon. But astronomers got a good look at the object, which turned out to be a lot more interesting than originally thought — it’s a binary asteroid.
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Carol Christian
& Jim O'Leary
