Of the nearly 300 planets which are currently known to orbit other stars almost all are much larger in size than Earth and none are believed to be habitable. Kepler’s objective is to statistically estimate the total number of Earth-size planets orbiting sun-like stars within their habitable zones and by doing so bring scientists closer to answering the ultimate question: Is there life in outer space? According to NASA, the spacecraft will survey more than 100,000 stars in the Cygnus-Lyra region of the Milky Way galaxy over a period of three years, following the path of Earth’s orbit around the Sun.
“This is a historical mission. It’s not just a science mission,” said NASA associate administrator Ed Weiler during a pre-launch news conference. “It really attacks some very basic human questions that have been part of our genetic code since that first man or woman looked up in the sky and asked the question: Are we alone?”
Kepler launched into space from Cape Canaveral Air Force Station in Florida on top of a Delta II rocket. Just days before the launch NASA’s Orbiting Carbon Observatory, using a Taurus rocket, failed to reach orbit. This prompted the agency to postpone Kepler’s original March 5th launch date to the following day in order to allow engineers time to make sure no similar issues will arise with Kepler’s Delta II.
For each detected planet, Kepler will supply astronomers with enough data to calculate its size, mass, orbital period, distance from star and surface temperature; by analyzing this information, astronomers will then be able to assess where to look for potentially habitable worlds. “Once we know how many there really are then NASA will be able to build space telescopes that can actually go out and take a picture of that nearby ‘Earth’ and measure the elements and compounds in the planet’s atmosphere and give us some hint as to whether or not it’s got life,” said Alan Boss, one of the astronomers involved in the Kepler mission. “Sometimes, people call this the golden age of astronomy. I think it’s more like the platinum age of astronomy. It’s beyond gold,” he added.