美科学家称未来25年内可找到外星人

　　According to the Space.com, on August 15, Seth Shostak, an astronomer and researcher, the proof of extraterrestrial intelligence could come within 25 years. Shostak said he based his estimation on the Drake Equation, a formula conceived by SETI pioneer Frank Drake.

　　The equation takes into account a variety of factors, including the rate of star formation in the galaxy, the fraction of stars that have planets, the fraction of planets that are habitable, the percentage of those that actually develop life, the percent of those that develop intelligent life, the fraction of civilizations that have a technology that can broadcast their presence into space, and the length of time those signals would be broadcasted.

　　“Taking the recent developments of science into consideration, it will not take scientists too long to discover an alien signal,” said Shostak.

　　The SETI quest is set to take a leap forward when the Allen Telescope Array, a network of radio dishes under construction in northern California, becomes fully operational. By 2015, the array should be able to scan hundreds of thousands of stars for signs of extraterrestrial intelligence, Shostak said.