http://www.newsweek.com/frbs-mystery-radio-signals-deep-space-might-be-blocked-way-earth-1191673

Scientists studying mysterious radio signals coming from deep space have discovered something “really unexpected”—that they do not appear in lower frequencies, potentially making the cosmological phenomena even more bizarre.

Fast radio bursts (FRBs) are signals emanating from an unknown source in deep space. The first FRB discovered in 2007 and since then dozens more have been documented. They appear to come from extremely high energy events, but because they last just a few milliseconds, determining their origin has been difficult.