In 1967, a possible alien signal appeared in the constellation Vulpecula. Jocelyn Bell of Cambridge University picked up regular radio ‘beeps' that occured every 1.3 seconds. They looked artificial, so her team named the source LGM-1 (for ‘little green men'). However, LGM-1 turned out to be a rotating neutron star- the first one ever discovered.
Scientists revisiting archived observations made by the Parkes Observatory in New South Wales, Australia in 2007 noticed something odd. They saw a brief, yet extremely bright burst of radio waves that lasted just five milliseconds. Nothing like it had ever been seen before. But in April this year, a similar signal ws reported on the other side of the world at Puerto Rico's Arecibo radio telescope.
Researchers now think there's good evidence that these ‘fast radio bursts' (FRBs) are not only real, but very common - and they come from vast distances far beyond our own Galaxy. Nobody knows what causes them, but could they possibly be evidence of intelligent Aliens trying to get our attention?
The Parkes Observatory has a vast 64 m-diameter radio dish, which is one of the world's oldest large movable dishes. It recorded an FRB on 2001, although it wasn't until several years later that astronomers noticed the strange signal.
Stappers says he has no personal hunch about what the sources of FRBs are, but he hopes that detecting more will resolve the issue. “We are working very hard to find more of them, and also to pinpoint them in the sky more accurately to try and find their host location," he says. “Are they in galaxies? And if so, where in the Galaxy - in the centre?"
Until then, FRBs will have to be filed among unsolved mysteries, alongside the ‘Wow! Signal'. This strong, narrowband radio burst lasted more than a minute and was detected by Ohio's Big Ear radio telescope in 1977. Jerry Ehman, the Astronomer who spotted it, wrote ‘Wow!' on a printout of the signal. The Wow! name has struck, but the signal has never been seen again.
The chances are that the fast radio bursts are something natural, rather than signals from little green men. But what causes them will no doubt baffle astronomers for some time.
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