New Clouds at Titan

Titan as seen by Gemini and Keck
Titan as seen by Gemini and Keck

This is kind of cool. Astronomers using the Gemini and Keck observatories on Mauna Kea, Hawai’i have spotted clouds in the atmosphere of Saturn’s largest moon, Titan. This isn’t the first time clouds have been found; astronomers have also seen them at Titan’s south pole and reasoned that they were caused by solar heating of the polar region.

However, these new clouds were spotted in early 2004 at the mid-latitudes of the moon, and are not likely to be caused by solar heating. So, what could be driving the formation of cloudy features in Titan’s nitrogen atmosphere? One explanation could be something happening on the surface that affects the atmosphere, like methane geysers or volcanoes that spout icy slush instead of lava (called cryovolcanism). It’s also possible that these features are being driven by some sort of changes in the global winds that circulate in the upper parts of Titan’s atmospheric blanket. The good news is that astronomers have a reporter “on site” in the form of the Cassini-Huygens mission. It’s likely the spacecraft has also recorded observations of these clouds and we may hear more about them from Cassini mission scientists. Incidentally, those researchers are gearing up for a big event on Christmas Day, 2004: the launch of the Huygens probe toward Titan, and an eventual surface landing sometime in the middle of January. Keep an eye out for more Titan news in the coming days and weeks!

Oh Moon, Lovely Moon

I went to pick up some stuff at CompUSA on Tuesday afternoon and on the way home I was treated to the most beautiful scene in the late afternoon (and yes, darkening!) sky. The crescent Moon was hanging low in the west and I could easily make out the effects of earthshine on the “old moon in the New Moon’s arms.” It was really lovely. Of course, the weather’s getting colder now, so the sky just sparkles in the chilly air.

I like watching the Moon, and try to catch a glimpse of it each day (and night), from the first thin crescent after New Moon to the waning crescent old Moon at the end of each monthly cycle. This month it’ll be full on December 26, so if you get new binoculars or a telescope for Christmas, you’ll have a lovely natural target to try out with your treasure.

Of course at its fullest this month (December 26th), the Moon will be bright enough to nearly wash out the view of a celestial visitor making its way between the constellations Eridanus and Taurus—Comet Machholz! You can go out and find it now while the Moon isn’t interfering, although the comet promises to be a finer view in January. SkyandTelescope.com has a helpful online story and finder chart if you’re interested in doing a little comet-tracking!

But, back to the Moon. I’ve always been fascinated with it. It’s the first (and so far only) other place in the solar system where humans have landed. It provides a menagerie of fascinating craters to explore, not to mention cracks and rilles and mountains. You could easily spend months exploring the Moon’s surface with nothing more than a good pair of binoculars.

So, if you’re out holiday shopping the next few nights after work, take a moment to stop and look up at the Moon. It’s a fine break from the ringing of the cash registers, the endless holiday music, the stuffy buildings, and maddening crowds.