Rare sighting of killer whales off Nantucket coast.

Four killer whales, including an adult male, an adult female, and two juveniles, were spotted swimming off the coast of Nantucket, an "unusual" sighting for Massachusetts waters. The sighting shocked local scientists who were conducting an aerial survey of marine life in the area. Orcas are not commonly seen in New England waters, and the only known orca in the area is "Old Thom," a large male who is known to swim alone. The sighting was described as "unreal" by the researchers.