What's up with Pluto?

Pluto, that used to be a planet but got laid off, is giving itself a make over. Hubble imagery analyzed over several years by planetary scientist Marc Buie at the Southwest Research Institute shows rapid color changes between 1994 and 2003. The Hubble is a powerful telescope but Pluto is rather small and very far away so this is still amazing:

Credit: NASA, ESA and M. Buie (SwRI).

The color changes are considered to be the result of methane ice sublimating into the atmosphere as the northern spring progresses. Paul Gilster at Centauri Dreams noted this gives rise to a new mystery:

I thought the liveliest part of the teleconference on Pluto yesterday was Marc Buie’s response to what had appeared in his datasets. Buie (Southwest Research Institute) was looking at imagery collected by the Hubble Space Telescope from 2002 to 2003 and comparing it with the results of earlier ground-based observations, as well as with Hubble pictures taken in 1994. The dramatic reddening seems to have occurred between 2000 and 2002, even as the illuminated northern hemisphere continued to get brighter.

Asked about his reactions to the newer Hubble imagery, Buie was candid:

“The color change in such a short period had me scared, because it’s so hard to understand. I’ve been checking absolutely everything I can think of, wondering if I screwed this up somehow and got the wrong answer. If I did, I can’t find the mistake.”

Another key point: In the Hubble imagery, the color of Charon remains the same throughout, whereas the reddening of Pluto is pronounced.

Credit: NASA, ESA and M. Buie (SwRI).

Something weird is going on way out there. The enigmatic object, now considered to be a Kuiper belt object has some stories to tell. Rather than a frozen ball of ice, Pluto is turning out to be a dynamic world, with seasons, an atmosphere and a varied surface silently lurking in the dark.

New Horizons is due to reach Pluto and Charon in 2015 to capture the first close-up images of the frigid ex-planet. In addition it will acquire chemical and spectral data so maybe Pluto will tell us a few of those stories and hint at a few more. Bet on surprises. I can hardly wait.

Who is cutting the farts of Mars?

The discovery of methane in the atmosphere of Mars has both astronomers and biologists in a tizzy. There really shouldn't be any in the atmosphere so this is a very exciting mystery. There are a few equally plausible reasons it could be there. A geological one, in that internal heat causes subsurface water to react with carbon dioxide, a chemical one from the oxidation of iron, and a biological one, being made by the waste of bacteria. Naturally it's the last one that's generating interest. Given the many depictions of martians in popular culture, it would be deliciously ironic that we would finally find them by their flatulence. Image credit: NASA

Winter wonderland

Nasa's Phoenix Lander has detected snow falling on Mars.

As if we didn't have enough to worry about

We're being tugged at by forces from outside the known universe. If the universe isn't big enough for you, cosmologists are talking about multiverses now.

Bicycling across the ring plane

The rings of Saturn have to be one of the most bizarre and spectacular structures in the solar system. Like a vinyl record nearly 130,000 miles across, they were one of the first things Galileo discovered when he peered through his telescope.

I always wondered what this huge disc made of ice chunks looked like up close. Since I love to check in to the Cassini site to see the latest, if there's a new view I look at the scale, usually in miles per pixel to get an idea how big the structures are.

It's getting closer. This picture, cropped from here, is a little under a half-mile per pixel. I added the little bracket, 10 pixels wide, which is about the length of my daily commute. My guess is that these ridges would appear like low hills if I could float next to the ring plane.

Cassini is due to pass through the plane next week, and again in the spring. I hope we'll get ever closer views of this amazing object.

Valleys of Enceladus

Cassini made its closest flyby of Saturn's mysterious ice moon Enceladus on Tuesday, snapping pictures as it whizzed by at 40,000 mph. The valleys are cracks in the ice that covers the small moon. Scientists believe the cracks are caused by liquid water under the ice.

This flyby showed that the jets of water vapor that Cassini discovered emerge from these cracks.

This picture was taken 545 miles above the surface with a resolution of about 20 feet per pixel. The lumpy objects all over the hills are said to be house-sized ice boulders, but I dunno. From this angle they look like trees dotting an arid, mountainous terrain. Every answer begets new questions.

Cool Astronomy Stuff

Lots of interesting discoveries lately:

Phoenix has hit paydirt on Mars. It was sent there to look for water ice and that's what it found.

A lake of liquid ethane was found on Titan. That makes Titan the only other body besides Earth to have a surface liquid.

Scientists have figured out what the first star looked like. Centauri Dreams speculates what that means for civilizations besides our own.

Space case

Last night we went to a meeting of the Sonoma County Astronomical Society. We'd been to one back in October that was really interesting, with a talk given by an engineer for NASA who worked on the Hubble telescope. This time the speaker was Bernard Pietsch, who is a longtime member of the group.

I dunno. I thought it was a little too Da Vinci Code. The other people in the room seemed pretty skeptical as well. But LeeJ got a handmade replica of the Philosopher's Stone, although the way Pietsch described it was different than anything we had heard. Pietsch claims to be in possesion of the Stone, and said it explains the mysteries of the universe. So why hasn't he gotten us out of Iraq?