It doesn’t take a humongous telescope to discover other worlds.
Astronomers, including scientists from the Lowell Observatory in Flagstaff, have detected a planet larger than Jupiter orbiting a star some 500 light-years from Earth.
They used small, amateur-styletelescopes.
More than 200 planets have been found circling stars other than the sun, but the use of small telescopes is significant, said Jonathan Lunine, a University of Arizona professor of theoretical planetary science and physics, as well as a scientist on the Cassini mission to Saturn.
Because larger scopes are booked years in advance, smaller, cheaper telescopes offer flexibility.
The newly discovered planet, named TrES-2, showed up in the constellation Draco when it passed in front of its sun, blocking about 1.5 percent of the normal starlight emitted, said Francis O’Donovan, a graduate student at the California Institute of Technology and lead author of a paper noting the discovery.
The planet makes a revolution around its sun every 2 1/2 days, O’Donovan said. It is so close to its sun, the surface temperature is estimated at 1,000 degrees Kelvin (about 1,340 degrees Fahrenheit).
Scientists often refer to such planets as “roasters,” Lunine said.
In October 2008, NASA is scheduled to launch a spacecraft called Kepler that will carry a 1-meter telescope. That’s larger than a backyard scope, but much smaller than the telescopes at many observatories.
“(The find) is a very nice precursor” to the Kepler mission, he said.
“We are really beginning to close in on planets the size or mass of Earth,” Lunine said. “After all, what we are really interested in is human beings (from other worlds).
“I think in the next decade or so, unless we have some real problems with the space program, we will have some Earth-mass, Earth-size planets under our belt,” said Lunine, a noted author on the search of such extra-solar planets.
“The very first transiting planet was observed with a relatively small telescope, a meter-size telescope in an automated observatory down south of Patagonia, (Ariz.),” Lunine said. “That was several years ago.
“The transit technique is a different way (of) discovering these things. In a way, it’s easier because you are looking at the dimming of the starlight by the planet passing in front of the star,” Lunine said.
A space-based telescope will allow a clearer view because Earth’s atmosphere will not create artificial fluctuations in the light of stars.
Lunine is excited about the search for Earth-like planets.
“I think it’s all about where we are in the cosmos, whether we are unique or whether we are one of many habitable planets,” he said.
For more on the Kepler Mission, go to http://kepler.nasa.gov.