Mauna Kea, Hawaii — Three massive volcanic eruptions occurred on Jupiter's moon Io within a two-week period, leading astronomers to speculate that these presumed rare "outbursts," which can send material hundreds of miles above the surface, might be much more common than previously thought. The observations were made using the W. M. Keck Observatory and Gemini Observatory, both near the summit of Mauna Kea, Hawaii.
De Pater discovered the first two massive eruptions on Aug. 15, 2013, using the near-infrared camera (NIRC2) coupled to the adaptive optics system on the Keck II telescope, one of two 10-meter telescopes operated by the W. M. Keck Observatory in Hawaii. The brightest, at a caldera named Rarog Patera, was calculated to have produced a 50 square-mile, 30-foot thick lava flow, while the other, close to another caldera called Heno Patera, produced flows covering 120 square miles. Both were located in Io's southern hemisphere, near its limb, and were nearly gone when imaged five days later.
A volcanic laboratory
Volcanoes were first noted on Io in 1979, and subsequent studies by the Galileo spacecraft, which first flew by Io in 1996, and ground-based telescopes show that eruptions and lava fountains occur constantly, creating rivers and lakes of lava. But large eruptions, creating vast lava flows in some cases thousands of square miles in area, were thought to be rare. Only 13 were observed between 1978 and 2006, in part because only a handful of astronomers, de Pater among them, regularly scan the moon.
- Global near-IR maps from Gemini-N and Keck Observatory in 2010, with a special focus on Janus Patera and Kanehekili Fluctus
W. M. Keck Observatory
Imke de Pater
Katherine de Kleer