WASHINGTON -- Stephen Hawking says it is too risky to try to talk to space aliens.
Oops. Too late.
NASA and others have already beamed several messages into deep space, trying to phone E.T.
Members of the U.S. space agency, which two years ago broadcast the Beatles song "Across the Universe" into the cosmos, on Wednesday discussed the latest search strategy for life beyond Earth.
"The search for life is really central to what we should be doing next in the exploration of the solar system," said Cornell University planetary scientist Steve Squyres, chairman of a special National Academy of Sciences panel advising NASA on future missions.
The academy panel is looking at 28 possible missions, including trips to Mars and the moons of Jupiter and Saturn. And NASA is focused mostly on looking for simple life like bacteria in our solar system rather than fretting about potential alien overlords coming here.
Just days ago, Hawking said on his new TV show that a visit by extraterrestrials to Earth would be like Christopher Columbus arriving in the Americas, "which didn't turn out very well for the Native Americans."
The famous British physicist speculated that while most extraterrestrial life will be similar to microbes, advanced life forms would likely be "nomads, looking to conquer and colonize."
The comment reinvigorated a three-year debate roiling behind the scenes in the small community of astronomers who look for extraterrestrial life, said Seth Shostak, a senior astronomer at the SETI Institute, which looks for aliens. Should astronomers ban purposeful messages into the universe for fear of attracting dangerous aliens?
Shostak maintains it doesn't really matter, saying that approach is unnecessarily fearful.
While some people think broadcasting into the universe is "like shouting in a jungle, not necessarily a good idea," Shostak asked, "Are we to forever hide under a rock? That to me seems like no way to live."
About 20 years ago, NASA held a conference on this issue. Back then, most of the experts were worried about attracting the wrong type of aliens, said Christopher Kraft, the ex-NASA Johnson Space Center director who created Mission Control.
But Kraft, a NASA legend who received a lifetime achievement award Wednesday from the Smithsonian Institution, said he would welcome aliens. "I might just learn something," he said.
MIT planetary scientist Sara Seager doesn't think much of the broadcasts to space because so far they are pointed at random, not toward Earth-like planets.
"We wouldn't even know where to send our message, it's so vast out there," Seager said.