So what you say? Well, these discoveries seem to come as a surprise, so how come we can be so definitive about mans effect on global warming?
Double-Sun Planet Discovered, à la 'Star Wars'
Detected by the National Aeronautics and Space Administration's $600 million Kepler space telescope, it is the first confirmed solar system of its kind, turning a Hollywood fantasy into an astronomical fact. Called Kepler-16b, the Saturn-size planet circles its twin stars in the constellation Cygnus about every 229 days, the researchers reported in Science.
"The reality goes beyond the imagination of the most creative theorist in astronomy or science fiction writer," said astrophysicist Fred Rasio at Northwestern University, who wasn't involved in the work. "Just about anything you could think of as a planetary system is actually out there."
The discovery capped a week of new findings about worlds beyond our own solar system. All told, four research teams in Europe and the U.S. reported finding 74 previously unknown exoplanets, as worlds orbiting other stars are called, including 16 that appear to be only slightly larger than Earth and with gravity favorable to life as we know it.
One of them, with about 3.5 times Earth's mass, may be orbiting near its parent star's so-called habitable zone, in which water may be liquid and conditions possibly ripe for life, said astronomers at the European Southern Observatory, who announced the find earlier this week.
It was among a trove of 50 exoplanets they detected around nearby stars using a spectrograph called the High Accuracy Radial-velocity Planet Searcher (HARPS), based at the La Silla Observatory in Chile.
So far, for reasons ranging from toxicity to temperature extremes, none of the 683 confirmed exoplanets seem capable of harboring life. No one can say with certainty whether any habitable planets exist outside our solar system.
Even so, the cascade of finds offers growing evidence that alien worlds may outnumber the stars themselves.
The HARPS team, led by Michel Mayor from the University of Geneva in Switzerland, estimated that about 40% of all stars like the Sun have at least one planet of Saturn's size or smaller. So far, the Kepler mission scientists have found more than 170 star systems in which two, three, four, five or even six planets all orbit one star.
"The universe is teeming with planetary systems of multiple planets, many of which are nearly the size of Earth," said plant-hunting pioneer Geoffrey Marcy at the University of California in Berkeley.
Among the other unearthly wonders discovered in recent months are an exoplanet blacker than coal and a world stripped to a diamond-like core. A third newly found exoplanet is blasted by its parent star with X-ray bursts so fierce that the radiation is eroding the planet's surface at a rate of five million tons a second.
Stranger still, a star survey of the Milky Way by astronomers in Japan and New Zealand earlier this year discovered a new class of Jupiter-size planets that float free of any star at all, swimming about on their own in the dark. They estimated that there may be twice as many of these orphan planets as stars.
Earlier this week, British astronomers in the Wide Angle Search for Planets (WASP) project announced they had found 23 giant, hot exoplanets, each about the size of Jupiter and, no doubt, with crushing gravity. These exotic worlds circle their stars so closely that they complete an entire obit about every five to eight days, the researchers said.
The WASP group monitors 10 million stars for signs of exoplanets by taking images of the night sky every 10 minutes with an array of cameras in South Africa and in the Canary islands. Their research, which hasn't yet been published, was discussed at the Extreme Solar Systems conference this week in Jackson Hole, Wyo.
"We are finding planetary systems which are very different from our own," said astrophysicist Coel Heiler at the U.K.'s Keele University, whose group runs the WASP search in the Southern Hemisphere.
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