ET may be calling us:-http://www.newscientist.com/article/mg22630153.600-is-this-et-mystery-of-strange-radio-bursts-from-space.html#.VR3TGWBFC1u-"BURSTS of radio waves flashing across the sky seem to follow a mathematical pattern. If the pattern is real, either some strange celestial physics is going on, or the bursts are artificial, produced by human - or alien - technology.-"Telescopes have been picking up so-called fast radio bursts (FRBs) since 2001. They last just a few milliseconds and erupt with about as much energy as the sun releases in a month. Ten have been detected so far, most recently in 2014, when the Parkes Telescope in New South Wales, Australia, caught a burst in action for the first time. The others were found by sifting through data after the bursts had arrived at Earth. No one knows what causes them, but the brevity of the bursts means their source has to be small - hundreds of kilometres across at most - so they can't be from ordinary stars. And they seem to come from far outside the galaxy.-"The weird part is that they all fit a pattern that doesn't match what we know about cosmic physics.-"Michael Hippke of the Institute for Data Analysis in Neukirchen-Vluyn, Germany, and John Learned at the University of Hawaii in Manoa found that all 10 bursts' dispersion measures are multiples of a single number: 187.5 (see chart). This neat line-up, if taken at face value, would imply five sources for the bursts all at regularly spaced distances from Earth, billions of light-years away. A more likely explanation, Hippke and Lerned say, is that the FRBs all come from somewhere much closer to home, from a group of objects within the Milky Way that naturally emit shorter-frequency radio waves after higher-frequency ones, with a delay that is a multiple of 187.5 (arxiv.org/abs/1503.05245)."