September 30th, 2010

Meade telescope

Astro-Porn of the Day: Jupiter and Io dance

Around 1:00am tonight, I took out the telescope to view Jupiter, which is about as close as it'll be until 2022. First the bad news: My 'scope's hand controller stopped working, so I couldn't align it, use the clock drive, or anything else. Better news: I can still sight and capture objects without all those modern doohickeys, even if I've been spoiled by a robotic GPS system. Best news: Without realizing tonight was a big deal, I happened to catch Io's transit across the disk of Jupiter. Wow, whatta sight! Looked a lot like this tonight:

Click the image to see more Jupiter photos by AztecastroMcJ on Flickr.

It was a bit of a pain to adjust both altitude and azimuth every few seconds to keep Jupiter and its mini planetary system in the eyepiece's field of view, but I pulled up a stool and just nudged it as needed. Just like the old days, before battery-powered, satellite-sensing, cylon-scopes took over.

Right now, Jupiter is so darned bright that I used filters to see if one might improve the view (partially by dimming it, partially by filtering out too-bright colors), and indeed the Mars filter brought out a huge variety of textures and colors in Jupiter's stormy atmosphere. But I ended up preferring the warm, natural colors of my favorite planet sans filter in a William Optics 33mm Swan mega-eyepiece (about the size of a small telescope). The Baader Planetarium 17mm Hyperion eyepiece provided a pretty kick-ass view at twice the magnification, but having to adjust every second or three inspired me to use the big, low-power unit instead.

I couldn't identify the high-contrast dark spot on the face of Jupiter - alien vessel? asteroid strike? - but figured it must be one of its Galilean satellites. When I got back inside, a quick search found this super-neat applet to find the position of Jupter's moons, and discovered I was, indeed, right - it was Io. To see the Jovian system as I saw it during the transit, set the time to 06:30 (when I first captured Jupiter) through 07:00 (when Jupiter started grazing the treetops in my back yard) at -5 time offset. What an AWESOME tool! Want to know which moons you're seeing on a particular night, or plan your viewing for during an occultation or transit? Check out this page first.

Okay, now the super-excited is wearing off a little and the sleepy is hitting. G'night, and clear skies!

Little Prince

Astro-Porn of the Day2: Gliese 581g, or Earth-Like Exoplanet Discovered!

I just learned from my pest-control dude ("Schendelize 'em!") that we've discovered the first truly habitable (by humans) exoplanet, Gliese 581g. It's Earth-sized (three Earth masses) and orbits in the middle of its star's habitable zone, where liquid water could exist on the planet's surface. This puppy is the most Earth-like exoplanet yet discovered and the first strong case for a potentially habitable one. Here's a close-up, photographed by the Vanguard generation ship, launched 3000 years ago from the island-nation of Atlantis:

Click the image to see the story. NOTE: The thing about Atlantis and Vanguard might not be true.

"New Earth," as the Vanguardians call it, is only one of two new planets discovered orbiting the nearby red dwarf star, named Gliese 581 by Earth-humans. This brings the tally of known planets around this star to 6, the most yet discovered in a planetary system other than our own. As in our Solar System, the planets around Gliese 581 have nearly circular orbits, though 581g (the Earth-like one) has an orbital period (aka "year") of only 37 days - in really close for good ol' Sol, who'd burn it to a crisp, but Gliese 581 is a feeble red dwarf star, so it's comfortably warm and has, I'm sure, the most amazing sky of any Earth-like planet, being so close to its parent. Its mass indicates that it is probably a rocky planet with a definite surface and that it has enough gravity to hold on to an atmosphere. Because it's tidally locked (doesn't rotate), the 581g-ans who live on the side facing away from the sun live in cyberpunkey perpetual night, gambling their lives against AI overlords. And stuff.

Money shot: "The fact that we were able to detect this planet so quickly and so nearby," sez Steven Vogt, who leads the Lick-Carnegie Exoplanet Survey (shut up your inner 12-year-old), "tells us that planets like this must be really common. If these are rare, we shouldn't have found one so quickly and so nearby," Vogt said. "The number of systems with potentially habitable planets is probably on the order of 10 or 20 percent, and when you multiply that by the hundreds of billions of stars in the Milky Way, that's a large number. There could be tens of billions of these systems in our galaxy."

Tens of billions of Earth-like planets in our galaxy, alone. Ponder that.

Here's the paper.

We live in amazing times!