The light-sensitive area on each CCD detector measures 45.0mm by 59.0mm, encompassing 1, 966 pixels by 4, 500 pixels.

BBC: A billion pixels for a billion stars

Working on a leash, one of the group's trained African rats can clear an area in 30 minutes that would normally take someone with a metal detector two days, Mr. Cox said.

WSJ: Sniffing Out a More-Efficient Mine Sweeper

He told Australian media the prospector had been using a state-of-the-art metal detector, which meant he was able to find the gold relatively deep underground in an area which had been searched many times in the past.

BBC: The gold nugget found in Ballarat