At precisely 10:49 p.m. EST, NASA’s “Kepler” telescope was successfully kicked off into space, embarking on a mission that the agency says “may fundamentally change humanity’s view of itself.” The telescope will search the nearby region of our galaxy for the first time looking for Earth-size planets, which orbit stars at distances where temperatures permit liquid water to endure on their surface – a region often referred to as the “habitable” zone.
on the launch pad
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.
The Kepler telescope will focus on observing drops in a star’s brightness – an event which may signal that an orbiting planet is passing in front of it. According to NASA, the measurement instruments aboard the spacecraft are so precise they can detect changes in brightness of 20 parts per million in stars that are thousands of light years away. “Being able to make that kind of a sensitive measurement over a very large number of stars was extremely challenging,” said Kepler project manager James Fanson. “So we’re very proud of the vehicle we have built. This is a crowning achievement for NASA and a monumental step in our search for other worlds around other stars.”
|Inspection of the primary mirror honeycomb|
structure. The mirror has been 86% light
weighted. That is it only weighs 14% (1/7)
that of a solid mirror of the same dimensions
(Credit: NASA and Ball Aerospace).
Since the confirmation of the discovery of the first “exoplanet
” in 1995, astronomers have been mesmerized by the possibility that such planets may be home to some form of life, much like our own planet Earth. While most of the discovered planets turned out to be gas giants, some were classified as “super Earths” by the scientists – those that are several times the mass of our planet and too hot to support life. Only last month, the European COROT
telescope stumbled on the smallest terrestrial exoplanet found so far, the rocky surface of which showed to have scorching temperatures reaching 1500 degrees Celsius.
“The density of these planets has been astounding,” said William Borucki, science principal investigator for the Kepler mission, who has been working on the project for 17 years. “We’re finding planets that float like a piece of foam on water, with very, very low densities. We’re finding some planets where the densities are heavier than that of lead.”
|Kepler Diagram (Credit: NASA)|
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.
More information on the Kepler mission can be found on NASA’s website