A rare white killer whale was spotted in Alaska's Aleutian Islands. 

The whale was spotted last month while scientists aboard the Oscar Dyson, a National Oceanic and Atmospheric Administration research ship, were conducting an acoustic survey of pollock near Steller sea lion haulout sites.

It had been spotted once in the Aleutians years ago but had eluded researchers since, even though they had seen many of the more classic black and white whales over the years.