In slightly reassuring news, astronomers have discovered a planet right in the middle of the habitable zone of its star, where temperatures are around a balmy 70 degrees fahrenheit, similar to that of Key West. According to Simon Worden, director of the NASA Ames Research Center, itâ€™s â€œanother milestone on the journey of discovering Earthâ€™s twin.â€
The truth of the story isnâ€™t actually as rosy as it sounds. The planet, named Kepler-22b, is 2.4 times the size of the earth, but its mass and composition has not yet been determined, meaning it could be rocky or loaded with ice. What the scientists DO know is that there are no other planets like this in our solar system.
Oh, and itâ€™s 600 light-years away, so we canâ€™t really hitch a spaceship ride there as soon as pollution starts to get the better of us.
The Kepler telescope, designed to scan the skies for Earth-like worlds, found the planet after seeing the orbit edge. Every 290 days it transits the starâ€™s surface, blocking a small fraction of its light.Â The first of three transits occurred a few days after the launch of Kepler in 2009, the third seen just before Christmas in 2010.
The planet is located right in the middle of the starâ€™s habitable zone, the region where temperatures are neither too hot or too cold for liquid water to exist, and it conveniently orbits a star very similar to the Earthâ€™s sun. The only discovered habitable stars in the past have either orbited small red dwarf stars, or were located at the edge of the habitable zone with harsh temperatures.
This still doesnâ€™t answer questions about extraterrestrial life, sadly. According to Jill Tarter of the SETI Institute, â€œWe donâ€™t know whether Earth as it is, and life as we know it, is very unusual or very common.â€ However, it will be obvious that life is widespread if scientists do find another place in the universe where life has developed. â€œIn this field, the number two is important. We count one, two, infinity.â€
With the right technology, do you think humans could be visiting this planet in a few hundred years or so? Between this and the increasing chance of discovering life elsewhere, it sounds like anything is possible.
Image: Artistâ€™s rendition of Kepler-22b (NASA)