Uranus: Mysterious White Spot May Be Storm; Amateurs Invited on Facebook to Observe

Nov. 2, 2011 — -- Something strange is happening on the planet Uranus. A fuzzy white spot has appeared on its frigid blue cloud tops, 1.8 billion miles from the sun, and astronomers say it's probably a giant methane storm, something unimaginable on Earth.

What do you do if you're a serious astronomer, poring over the images from the Gemini Observatory in Hawaii? You go on Facebook -- not some obscure scholarly network-- to invite amateurs to join in. (Images are being collected by an organization called the International Outer Planet Watch.)

"This is a science that's for the public," said Heidi Hammel, a planetary scientist who's studied the outer ice giants Uranus and Neptune, the seventh and eighth planets from the sun. "There is action going on right now, and you can be part of it."

When she said right now, she meant now. The first images of the storm on Uranus only came in on Thursday night, and it may only be 3-5 days before the storm fades from view. Hammel has filed a request for the Hubble telescope in Earth orbit to take a look at Uranus on a "target of opportunity" basis. If enough amateur astronomers chime in, Hubble will be diverted from other observations to turn toward Uranus before the moment passes.

"If you could look at it up close, I imagine it would look like a really tall anvil cloud," said Hammel.

It may be roughly similar in formation to a thunderstorm on Earth -- except that it's hundreds of miles across, if not more, high in Uranus' atmosphere.

Since the storm is not obscured by clouds above it, it appears 10 times brighter than the rest of the planet, report astronomers who have seen it this week. To amateurs, even with fairly large telescopes, it may show only as a faint dot. But if enough chip in, they may be able to calculate how quickly Uranus' frozen clouds are turning. Scientists say the planet rotates in just over 17 hours.

Uranus has had a tough time as planets go. It is just on the edge of visibility from Earth, appearing to the naked eye as a dim star -- if you live in a place with crystal-clear skies, far from cities. The astronomer John Flamsteed put it on a star chart as long ago as 1690, but only in 1781 did Sir William Herschel realize it was a planet, moving against the background of stars in the sky.

It takes 84 Earth years to orbit the sun once, and it's turned on its side relative to the other planets, perhaps because it was slammed -- twice, according to one computer model -- by debris as the solar system was forming. It's only been visited by one space probe, Viking 2 in 1986, which sped by on its way to Neptune and on out toward the stars.

So did Uranus have a bad day last week?

"No, it had a great day," said Hammel. "It's great when a planet that gets no respect does something really interesting."