美国有线新闻 CNN 来自外星人的问候? 加拿大侦测到外太空重复电波（在线收听）

What do the names Whirlpool, Black Eye, and Sombrero all have in common? Are they all appliance brands, names of galaxies, special ops forces, or oceanic reefs? These are all the names of galaxies, massive concentration of stars.

AZUZ: Of course, the one we live in is the Milky Way, which would have made that question too easy. And scientists say they have detected some sort of signal from outside it, fast radio bursts that repeat. Radio bursts, which are signals that only last for a millisecond or so, aren't that rare in space. But researchers say that last summer, a Canadian radio telescope recorded a burst six times from the same location, and that is said to be unusual.

This is only the second time that this type of signal has been found to repeat. So, what is it? No one knows.

Some people think they could be a form of communication from extraterrestrial life tr?ying to contact us. But scientists say that's probably not it. The bursts could come from neutron stars or a black hole. What they're hoping is to record more of them so they can be studied and used to explain their origin.