On Christmas Day, 1758, a German amateur astronomer and farmer named Johann Georg Palitzsch did something that would have made a great Christmas gift for English astronomer Edmond Halley. Johann “recovered” Halley’s Comet, meaning he was the first to observe this previously observed “dirty snowball” as it returned to the inner solar system. Edmond Halley (1656-1742) calculated the orbit of the comet that now bears his name based on previous sightings...

Many phases of the Moon ago — more than 200 — I came under the spell of earth science and wrote a lot about it for a number of years. This week, some of that ancient knowledge came back to visit as I gazed at a fantastic 28-image mosaic of Saturn’s moon Enceladus. You may see crusty cracked ice; I see the outlines of ice continents. At the American Geophysicial Union meeting in San Francisco this week, the halls are abuzz with talk of plate tectonics...

India’s Chandrayaan-1 lunar probe will fire a rocket Saturday, November 8, to insert itself into orbit. As I sat down to prepare a magazine news article about the mission earlier this week, I found myself lacking a decent piece of space art of the probe. A web search led me not to the Indian Space Research Organisation (ISRO), which lofted the craft, but to a talented space enthusiast in England named Doug Ellison . He kindly provided the image of...

If you want to witness something historic, get on the next flight to Sudan. That’s where a unique meteorological event may take place late tonight. Astronomer Rich Kowalski of the Catalina Sky Survey in Tucson discovered asteroid 2008 TC3 last night. And astronomers predict that tonight, on October 7 Africa time, the object will enter Earth’s atmosphere and burn up in a spectacular fireball. The asteroid is only a few meters across at most, so it...

Last week , I told you we would show you a new map of Mercury based on the January MESSENGER flyby. Here it is, kindly provided by one of NASA’s master mappers, Robert Gaskell of the Planetary Science Institute in Altadena, California. This image is an anaglyph — a flat image that simulates a three-dimensional view — of the fault scarp Beagle Rupes as it cuts across the crater Sveinsdóttir. The area shown here is about 160 miles (257 kilometers) square...

In centuries past, explorers would visit terra incognita — unknown lands — and bring new information back home to feed the master mappers of Europe. It hasn’t changed all that much — except the explorers are robot spacecraft and the master mappers of the solar system are scientists. Late Tuesday afternoon, I saw a NASA press release about one of NASA’s master mappers, Robert Gaskell. He’s a senior scientist at the Planetary Science Institute in Tucson...

The Galileo spacecraft photographed the binary asteroid Ida (the big one at left) and its tiny satellite Dactyl in 1993. Galileo Project/JPL/NASA Spinning asteroids or skinning cats — there are so many ways to do it. Let’s look at three methods recently in the news: One: The effects of sunlight In today’s issue of Nature , several scientists outline a mechanism by which sunlight striking at an angle “spins up” loose, rubbly asteroids, causing them...

Look out, here comes the “Is Pluto a planet?” debate — again. I wade into these waters with trepidation and wearing armored hip waders. But on the other hand, how often does a guy get a chance to stir up a pot of angry astro-hornets? I won’t regurgitate the backstory. If you are reading this, you have a browser and an Internet connection. If you are not current on the drama, just Google “Is Pluto a planet?” and come back when you recover from your...

NASA engineers have proposed a mission to an asteroid threatening Earth. Bruce Damer (DigitalSpace) I’m happy to report NASA may be planning to do more about the as-yet unaddressed asteroid threat to Earth than helplessly watch giant space rocks whiz by the home planet from time to time. The Guardian , a British newspaper, reported recently that some NASA scientists have written a report outlining a mission to asteroid 2000SG344. The object is about...

This just in from the hydrocarbon desk at Astronomy.com: Titan’s surface lakes and methane-ice-laden dune seas collectively hold hundreds of times Earth’s bounty of hydrocarbons (oil and gas). It’s a Texas oilman’s dream: hydrocarbons rain from the sky on Titan. To my mind, this could solve a lot of problems. Planetary scientists have been competing with NASA’s fantastically expensive manned space program for decades. Word on the aerospace street...