Daily Archives: July 19, 2009

astronomy, Jupiter

A New Dark Spot On Jupiter

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Planets Change!

Image of dark spot on Jupiter, captured by Anthony Wesley on July 19, 2009 at 1554UTC from Murrumebateman, Australia. Click to embiggenate.
Image of Jupiter with new dark spot in the southern polar regions, captured by Anthony Wesley on July 19, 2009 at 1554UTC from Murrumbateman, Australia. Click to embiggenate.

The big news today (July 19) is that Jupiter seems to have a dark spot in its south polar region.  The first images, posted by Australian amateur observer Anthony Wesley, ripped around the Web at the speed of light and have caught everybody’s attention.  Is this dark spot a storm? Evidence of some weather event stemming up from the lower atmosphere? An impact site?

The best way to tell would be image the planet in infrared, which I’m sure is happening as I write this. There are a number of infrared-enabled observatories that probably can look at this thing as a “target of opportunity.”

Regardless of what it is, observers will watch this thing as it rotates around the planet over the next few days to see track changes in its size and appearance.

This does look reminiscent of the impact sites created when pieces of Comet Shoemaker-Levy 9 smashed into the Jovian cloud tops in 1994.  As more astronomers look at this thing and follow its progress, we will certainly figure out whether or not this is an impact or a very cool new atmospheric feature forming in the upper cloud decks of the planet. Either way, it’s a great find for Anthony and a boon for planetary observers around the world.