It's part of the institute's public-outreach program during this year's International Year of Astronomy. And your choices are not culled from among chestnuts in Hubble's Greatest Hits; they are objects Hubble has never peered at.
If you like to think local, you can choose from among one star-forming region and two planetary nebulae in the Milky Way. The planetary nebulae are glowing clouds of gas – essentially a star's atmosphere – given off by sunlike stars in their death throes.
Or you can go deep and pick from among three galaxies. Well, four, really. One of the choices is to focus on a pair of galaxies interacting with one another. (As of this writing, the interacting galaxies have captured first place.)
Unlike old-style Chicago politics, vote early, but don't vote often. It's one person, one vote. The polls close on March 1. And this time, no hanging chads to worry about! The winning shot will be unveiled between April 2 and 5.
And if you're interested in getting a photo of the winning target, enter the institute's drawing. They'll make 100 images of the winning object available as door prizes. (Thanks to the Bad Astronomy blog for a 2 a.m. heads-up on this! Bad is a misnomer; it's really quite good.)
By the way, if you tell someone you're voting and they grumble about this use for such an expensive piece of hardware (someone over at NASA Watch calculated the cost at $100,000 to take one image), you can reassure them that you're just keeping a nifty space observatory busy during a dry spell.
Two of the observatory's three instruments are off-line until after NASA launches its fourth servicing mission to the telescope, currently scheduled for May. So from the standpoint of science, the food line isn't too long at the moment. And the time for taking the winning image apparently comes out of an allotment of observing time the institute director can distribute at his discretion.
So gently invite the grumpies to chill.
Video: In December, an astronomer using Hubble announced he had detected carbon dioxide on a planet orbiting a distant star. Here's a report on what he had to say about his discovery: