On November 13, 2008, NASA announced that the Hubble Space Telescope has taken a snapshot of a planet circling the star Fomalhaut. Obviously, this is the first planet other than our own that we know of orbits a base star. Other than this, why was this such a significant discovery?
The answer is related to the fact that the HST took the images in 2004 and 2006, and only just recently announced. Why wait?
The researchers waited because they wanted more time to study the images. It'd be really nice to have gotten a third shot in 2008, but the ACS camera on the HST which was used for the first two shots is broken. It was expected to be repaired a couple months ago, but then the servicing mission was delayed.
So, what's to study? It's not just a planet, it's a planet in a debris ring around the young star. So you have to sort of subtract the brightness of the ring to find the brightness of the planet. And the planet is brighter than expected. Perhaps it has rings like Saturn reflecting lots of light from the star. But more than that, one would like to see evidence of other planets forming. So there's lots to do.
What about the timing of the news release? Another image of planets in the same issue of Science? It doesn't look like a coincidence. The researchers waited as long as they could. IMO, they should have announced it soon after they'd figured out that it was a real effect in 2006. Then in 2009, when they snap their third shot, they could confirm it. Perhaps they've gotten time on the Keck or the VLT and gotten more recent data...
But imaging an extrasolar planet is a big deal. Being the first to do it in visible light is more bragging rights than a big deal, however. And this isn't the first planet that has been imaged. So, they went for a sound byte rather than explain that they're doing really cool planet formation science.
One of the troubles with sound byte science is that it's more of the same memorization of stupid facts that turns kids off to science in school. The cool stuff about science is getting your hands dirty doing experiments. Making mistakes. Getting results. I had much more fun measuring the speed of light - with a 3% error - than i'd ever have just memorizing the speed of light. If you want to accelerate the advancement of science, then push yourself to make mistakes faster. It's true for education as well.