GREENBELT, Md. - Jupiter now has a "black eye" to match its Great Red Spot.
The largest fragment so far of Comet Shoemaker-Levy 9 left "the most visually prominent discrete spot in 384 years of observing Jupiter," says Steve Maran of the Goddard Space Flight Center.
NASA photos released Tuesday reveal an Earth-sized dark spot and a larger horseshoe ring caused by the impact of fragment G, which hit Monday.
The planet has been studied since 1610 with early telescopes. The Great Red Spot is an atmospheric storm that's been observed for centuries.
About fragments H and K:
-- Maran says one observatory reported H created a blast 50 times brighter than Jupiter.
-- Fragment K created a fireball with an afterglow about three times Earth's size.
The fireworks are dazzling, but astronomers are baffled by the fragments' effects on Jupiter's atmosphere.
They expected the impacts to create bright white clouds containing water. Instead, the comet chunks have dotted Jupiter's southern region with mysterious black marks, says Keith Noll, Space Telescope Science Institute in Baltimore.
"We don't know what to make of seeing no water," says Noll, who adds that studies of the composition of the dark spots are under way.
Still to come: a "triple whammy" of three comet chunks beginning today, each striking Jupiter in roughly the same spot 10 hours apart.
Under the best viewing conditions - no clouds, no outdoor light - amateurs with 8-inch or larger telescopes now may be able to spot the spots.
