Amateur Astronomer Spies a Fresh Impact Scar on Jupiter

Amateur astronomers still do very important work. David Levy, who I am glad to say I knew in his amateur days in the 1970's, was a co discoverer of Shoemaker-Levy 9. In a sense this (small) story is the important story of the day. Long after all our politics are done and we are dust the music of the spheres will continue.

Amateur Astronomer Spies a Fresh Impact Scar on Jupiter

Follow-up observations on large telescopes confirm that something hit the gas giant

By John Matson   



A backyard astronomer in Australia made a major discovery early Monday morning when he noticed a newly formed spot on Jupiter —a spot that academics and NASA astronomers have now confirmed marks a recent impact on the giant planet.

Anthony Wesley of Murrumbateman had a new 14.5-inch Newtonian telescope at his home observatory trained on Jupiter when he noticed something unusual: a dark spot on the planet's outer layers that had not been there two days before. Because its location, size and rotation speed did not jibe with any of Jupiter's moons or their shadows, nor with any of its known atmospheric features, a feasible explanation eluded him. Observed massive impacts from comets or asteroids are extremely rare—when Comet Shoemaker-Levy 9 slammed into Jupiter in 1994, it was an unprecedented event watched intently from countless observatories.

"Could it actually be an impact mark on Jupiter?" Wesley wrote in his observation report. "I had no real idea, and the odds on that happening were so small as to be laughable, but I was really struggling to see any other possibility given the location of the mark."

He continued to photograph the planet, then returned to his house to e-mail others about what he finally concluded had to be a scar from a recent impact. Leigh Fletcher, a postdoctoral astronomer at NASA's Jet Propulsion Laboratory in Pasadena, Calif., happened to be part of a team with observing time on the NASA Infrared Telescope atop Mauna Kea in Hawaii when he and his colleagues got word of Wesley's unusual sighting. What is more, Fletcher's group was already going to train the three-meter telescope on Jupiter to observe its storms, working remotely from Pasadena.

"You can imagine the scene: We're all extremely excited, crammed around the computer screen to see those first images from the telescope facility," Fletcher says. "And there it was: an extremely bright feature on the southern hemisphere of Jupiter." It looked just like a medium-size impact from Shoemaker-Levy 9, Fletcher says, confirming Wesley's assessment.
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