Extremely rare, black "anti-auroras" helped create a peculiar E-shaped swirl of green light recently photographed over Alaska, experts say.
Aurora hunter Todd Salat spotted the unusual aurora on Nov. 22 above an unspecified location in southcentral Alaska at around 4 a.m. local time (8 a.m. EST). The luminous letter appeared seemingly out of nowhere and lasted for a few minutes while cycling through several shapes, all of which contained strange dark patches not seen in most auroras.
