First measured spectra of exoplanets
Disclaimer: The following post may contain astronomical awesomeness.
Scientists have announced the first spectra ever taken of exoplanets (planets outside our solar system). Using the Spitzer Space Telescope, the astronomers measured the spectra of two Hot Jupiters. This is truly a ground-breaking moment in observational astronomy. Spectral data can tell us so much about other worlds. For instance, these spectra showed a lack of water vapor and an abundance of silicate grains (sand/dust) in the planetary atmospheres, two observations that were totally not expected. The reason for taking spectra is that these planets are way too far away to be able to resolve an image in a telescope, but as long as you get a pinprick of light in your telescope, you can measure the different wavelengths of radiation using a spectrograph. Different atoms and molecules all have characteristic spectra, so the composition of the atmosphere of a planet can be deduced by measuring its spectra.
The coolest thing about taking spectra of planets is that it will reveal the presence of Earth-like life. Alien observers hundreds of light-years away could train their colossal telescopes on the Earth and take a spectrographic measurement which would immediately reveal the over-abundance of free oxygen in our atmosphere. Free oxygen cannot be naturally occurring; if left alone, it will quickly oxidate rocks on the surface and be bound up in molecules. The abundance of free oxygen means that there must be some process maintaining the disequilibrium and continually freeing up more oxygen. The only such process we know of that could work on large scales is photosynthetic life.
So these spectra of the Hot Jupiters are very interesting, but they haven’t revealed the presence of life (not that we would expect recognizable life in such environments). However, the groundwork has been laid, and hopefully the next generation of infrared space telescopes (including the James Web Space Telescope) will be able to take spectra of Earth-sized rocky worlds. A positive hit for life on one of those spectra would be the greatest astronomical discovery ever.
Update: Phil Plait has much more information on this awesome new discovery.
February 22nd, 2007 at 04:53
It is absolutely incredible that we’ve moved from detecting the presence of planets and then their masses and orbits to now getting glimpses of their atmospheres. Incredible.
February 22nd, 2007 at 08:53
The neatest part is that Spitzer Space Telescope wasn’t designed to do this and nobody would’ve even thought it possible five years ago (note there haven’t been any hardware changes since then). I have to give some huge props to the scientists who basically said, “You know what? Let’s do it anyway.”
And by the way, was my disclaimer right on or what? :-P
February 26th, 2007 at 04:05
Right!
Yes, it certainly does contain some astronomical awesomeness…though as anyone who visits my weblog would know, I tend to think astronomy is awesome in general. This is especially exciting though!
Hey I like this real-time preview you have for comments. Was that always there?
February 26th, 2007 at 09:56
Nope, the real-time preview is new. I found a great WordPress plugin. WordPress default doesn’t even have a way to preview comments, which is a rather large omission. But this plugin makes up for it handsomely. And yes, astronomy is awesome. I’m graduating with a minor in it in just a few months. I’m not sure how I’ll be able to put it to use, though.
February 27th, 2007 at 00:40
That, right now, is probably my biggest complaint about WordPress.com. I wish there were a way to preview comments, especially now that we have LaTeX.
February 27th, 2007 at 09:01
I noticed that when commenting on your blog. The use of LaTeX without previewing is comical. Sometimes when I’m using LaTeX on Wikipedia it takes me many, many tries. Do wordpress.com blogs allow you to install any plugins? Or do you not have that option? There are lots of great plugins out there; if you’re really serious about your blog, you should consider paying to host your site on various services like HostMonster, BlueHost, Dreamhost, etc. It’s as low as $5/month for all of the bandwidth you’ll ever need for hosting a blog, and you’ll be able to do whatever you like with your WordPress installation (including installing live previewing).
February 28th, 2007 at 00:12
Well, WordPress.com has been really good about continuously improving, so perhaps they will add that feature at some point.
No, we can’t install our own plugins. I have toyed with the idea of hosting my own weblog. WordPress.com was a good starting point, but now that I’ve been at it for a few months, perhaps it’s time to move on. Then again, my weblog is small; I don’t know if it would be worth it. One of the worries I have would be the loss of readership inherent in any move. WordPress.com also has sort of a “community” which helps other readers come across my entries. But the biggest obstacle would be the work in setting everything up; I really have no idea how I would go about setting up such a weblog.