Science 341, 53–56 (2013)

The single bright radio burst of 2007, known as the 'Lorimer Burst', caused a sensation as it was reported to be of extragalactic origin. It remains somewhat mysterious, although now its source is suspected to be terrestrial rather than celestial.

However, while using the Parkes 64-m radio telescope in Australia to scan the sky for pulsars and other pulsed radio sources, Dan Thornton and collaborators have detected four transient millisecond radio bursts that really do seem to have come from cosmological distances — up to 8 billion light years in one case. Moreover, they are more luminous than any known transient radio sources. Follow-up scans have detected nothing, suggesting that these new bursts hail from cataclysmic events such as galaxy mergers, explosions from supermassive black holes or magnetars, or possibly some as yet unknown source.

Given their transient nature, detection of fast radio bursts relies on looking in the right direction at the right time. The authors extrapolate that, across the entire sky, there should be 104 such bursts per day. To study them, large surveys using arrays of time-domain telescopes will be needed.