I’ve never met George Ricker, but in at least one respect I believe he thinks the way I do. Ricker is senior research scientist at MIT’s Kavli Institute for Astrophysics and Space Research, and he’s someone who can connect the exoplanetary systems we study with places we might eventually go. As witness this comment in a discussion of a planned satellite-based observatory being designed at the Institute:
“Decades, or even centuries after the TESS survey is completed, the new planetary systems it discovers will continue to be studied because they are both nearby and bright. In fact, when starships transporting colonists first depart the solar system, they may well be headed toward a TESS-discovered planet as their new home.”
It’s wonderful to see a ‘when’ rather than an ‘if’ when referring to starships, even though everyone concerned can appreciate the blue-sky nature of the comment. For my part, I’ll take whatever the physics will bear, from close-up imagery of terrestrial exoplanets to robotic probes pushed by fusion or lightsails, and just maybe down the line, vessels carrying human crews. It’s a goal worth dreaming about.
TESS refers to the Transiting Exoplanet Survey Satellite, which has caught a bit more media buzz than might be expected because Google is among its sponsors. Remember when we thought of Google as a search engine? Now it’s all over the place, mapping not only the planet but also the heavens through Google Sky. The synergy between the data collection capabilities of wide-field digital cameras and a company that makes its money sifting through information is obvious. TESS will use six such cameras, covering the sky in its entirety and measuring the brightness of some two million stars in total.
Image: Artist’s conception of a transiting ‘hot Jupiter.’ An all-sky survey like TESS should track down more of these, with the potential for landing smaller terrestrial-class worlds as well. Image copyright Mark A. Garlick / markgarlick.com.
The targets: G, K and M-class stars. Make the assumption that one star in a thousand makes a transit as seen from Earth. Observe two million stars and you’re looking at a couple of thousand transiting worlds, and perhaps more depending on how accurate our emerging views of planetary formation are. Design work for TESS is scheduled to be completed this year (you can read more about that and the scientific partnerships MIT has entered into on this project in this news release). For more specifics, David Latham (Harvard-Smithsonian Center for Astrophysics) offered a helpful description of TESS as well as the Kepler mission in a presentation he gave at the California Institute of Technology in 2007. The CfA is partnering with MIT on the TESS project.
Will TESS-discovered planets form the target list for our first interstellar probes? Conceivably, although that assumes that funding to build and launch the satellite is forthcoming. The earliest launch date is 2012. My own hunch is that within that time we may well have identified an Earth-sized planet that is unqualifiedly in the habitable zone of an M-dwarf, one whose orbital position is far less ambiguous than either Gliese 581 c or d. For that matter, if Greg Laughlin’s team can work out the arrangements, we may even have good radial velocity data on rocky worlds around Centauri B. So I wouldn’t put too much emphasis on TESS being first, but the more eyes we have for the exoplanet hunt the better.