In 2009 NASA launched the Kepler telescope. Its three-and-a-half-year mission; “To determine how common or rare planets like out own are in the galaxy,” says NASA scientist Thomas Barclay. Earth-like planets that have the potential to bear life, detecting them as they pass in front of their host stars which cause a tiny dimming fluctuation of the star’s brightness, called the transit method. Kepler’s photometer is so sophisticated and sensitive, it would be comparable to measuring the difference in light output as a butterfly passes through the beam from a lighthouse. It’s mission is to also greatly assist scientists in calculating how many of the billions of stars in the Milky Way Galaxy host Earth-like planets.
WWWMain investigator for the Kepler project and NASA astronomer, William Borucki, says this regarding Earth-like planets, “If they’re frequent, then there may be lots of life throughout the galaxy. They may just be waiting for us to call and say, ‘Hello, we’d like to join the club,’ or if we don’t find any, the answer may be just the opposite…maybe we’re alone, there isn’t anybody out there, there will never be a Star Trek because there’s no place to go to.” WW
Where to look
Trailing Earth’s orbit, the telescope orbits the sun once every 371 days, as it looks at one large area of space in the constellations Cygnus and Lyra, simultaneously measuring the variations of brightness of 100,000 stars every 30 minutes. Cygnus is 2,700 and Lyra is 1,200 light years away. These constellations were chosen because they are rich with stars and our sun doesn’t get in the way throughout the entire orbit of Kepler.
WWWAfter finding many of three types of planets—gas giants, hot-super-Earths, and ice giants, none of which can harbor life; the great quest now is to find those planets for which Kepler was specifically designed—those in the Goldilocks Zone of the stars they orbit,, those that are the size of Earth, and where liquid water can exist. Amazingly, Kepler scientists can determine the size of the planet, the size of the star, and the temperature on the planet all from a picture of light.
The Great Question
WWWKepler’s initial mission was planned for 3.5 years; in 2012 it was extended to 2016 essentially doubling the mission’s life. So far, Kepler has found 2,740 potential life bearing planets orbiting 2,036 stars, and 132 confirmed planets that could bear life. In January 2013, astronomers at the Harvard-Smithsonian Center for Astrophysics used the Kepler data to estimate that at least 4.5 billion Earth-size planets reside in the Milky Way Galaxy. Those seem like pretty good odds for life. See video below.