Other sky gazers are here at one of the summer’s occasional observing nights atop Blue Mountain, inside UM’s ’70s-era domed observatory, glimpsing Saturn and its rings and multi-billion-year-old, 500,000-star globular clusters. Meanwhile, McCrady wants to talk about the exoplanets Blue Mountain’s telescope can’t see. UM, led by McCrady, is embarking on a new project called MINERVA, a partnership between UM, California Institute of Technology and Penn State University that will search for small, rocky, Earth-like exoplanets that just might support life.
Through MINERVA, UM will have its own robotic telescope on Palomar Mountain, in Southern California, one of four telescopes in MINERVA’s array, putting the school, which has no graduate degree program in astronomy, at the forefront of the search for other life in this galaxy.
“It’s a game-changer for our department,” says McCrady, a tall, excitable, boyish-looking professor who gets goosebumps when talking—and he talks a lot—about MINERVA. (He also chokes up over the recent Mars rover landing.) “It catapults UM astronomy into the cutting-edge,” he says, “the frontline of research in exoplanets.”
While exoplanet studies took off in about 1995, the last couple of years have brought giant leaps in the field. One, McCrady explains, is that studies of stars in our galaxy have shown that the average star has 1.6 planets, so there are more planets than stars. The other is that there appear to be a lot more small planets than big planets.
“It leads to this crazy conclusion, based on observational facts, that there are probably more small, rocky planets than stars in our galaxy,” of which there are about 200 billion, he says. “So there are probably small rocky planets everywhere in our galaxy. That’s amazing. We didn’t know this five years ago... It’s probably the hottest field in astronomy right now.”
NASA’s Kepler Mission is a big part of that. It’s looking for habitable planets by staring at a portion of the Milky Way and measuring repeatable dips in stars’ brightness, which indicate that planets are essentially eclipsing the stars as planets transit around them. The mission, launched in March 2009, had found 2,321 unconfirmed planets as of late February.
MINERVA’s four small-aperture telescopes won’t focus on a large swath of the sky like Kepler, but on individual nearby stars: that is, stars about 50 to 60 light years away, which counts as “right next door” in galactic terms, McCrady says. MINERVA’s array will be the first exoplanet observatory of its kind in the United States, capable of both transit studies, like Kepler, and radial velocimetry. McCrady says MINERVA’s measurements will be as precise as any instrument’s in the world. “These small dedicated telescope studies like MINERVA,” he says, “they’re the explorer missions, they’re the test bed to go out and identify where the targets are that are super-interesting...The holy grail, if you will, is to find a sun-like star with an Earth-like planet that’s rocky and is the same distance as we are” from our sun.
UM Provost Perry Brown says MINERVA puts UM undergraduates “in line with some of the best graduate programs in the country” and “at the forefront of some leading technology and leading ideas with regard to astronomical science.”
MINERVA’s director, Caltech’s John Johnson, says he sought to work with UM specifically because of his familiarity with McCrady, whom Johnson calls “an outstanding scientist, an expert spectroscopist.” Johnson, McCrady and Penn State’s Jason Wright earned their PhDs at the University of California, Berkeley, where the trio “forged our scientific philosophy together,” Johnson says. “We all share this understanding that you don’t do science in a vacuum. If you can’t share the science you do with the greater public, then you’re not doing much of value.”
McCrady hopes the MINERVA array will be on the sky by early 2014. Last week, on the Caltech campus, concrete was poured for the foundation of the first telescope, Penn State’s, which should be ready for testing in October and put in place on Palomar Mountain in the spring. The second telescope in the array could be UM’s. But first, the school has to raise about $250,000 to buy its telescope. McCrady’s hoping to land grants to cover the bulk of the cost, but says “we’re not likely to say no to financial assistance from anyone on this project.” Brown says he thinks MINERVA is “exciting enough that it’s going to attract the attention of the right folks that need to help out.”
McCrady’s already looking well past that hurdle, into another realm entirely.
“We’re the front line,” he says. “We’re the frontier. We’re the explorers.”