Massive gas cloud around Jupiter revealed
NASA NEWS RELEASE
Posted: February 27, 2003
Using a sensitive new imaging instrument on NASA's Cassini spacecraft, researchers have discovered a large and surprisingly dense gas cloud, sharing an orbit with Jupiter's icy moon Europa.
The cloud's mass indicates the intense radiation Europa faces has more severe consequences than scientists thought, says Dr. Barry Mauk of Johns Hopkins University Applied Physics Laboratory (APL), Laurel, Md. Mauk heads the laboratory's research team whose findings appear in the Feb. 27 issue of the journal Nature. The mass also shows that Europa, in an orbit some 671,000 kilometers (416,000 miles) from Jupiter, wields considerable influence on the magnetic configuration around the giant planet.
"Surprisingly, Europa's gas cloud compares to that generated by the volcanically active satellite Io," Mauk said. "But where Io's volcanoes are constantly spewing materials, mostly sulfur and oxygen, Europa is a comparatively quiet moon, and the gas we see is a direct consequence of its icy surface being bombarded so intensely," he said.
"By acting as both a source and a sink of charged radiation particles, the dense gas torus gives Europa much greater influence than was previously thought on the structure of, and energy flow within, Jupiter's huge space environment, its magnetosphere," Mauk said.
The APL team studied images of Jupiter taken in late 2000 and early 2001 with the laboratory's Ion and Neutral Camera on NASA's Cassini spacecraft, now in route to Saturn. Mauk says this is the first substantial discovery made at an extraterrestrial planet using an innovative technique known as energetic neutral atom imaging.
Research team members at the APL and co-authors on the Nature paper, "Energetic neutral atoms from a trans-Europa gas torus at Jupiter," include Dr. Donald Mitchell, Dr. Stamatios Krimigis, Dr. Edmond Roelof and Dr. Christopher Paranicas. Krimigis, head of the Space Department at the laboratory, is principal investigator for Cassini's Magnetospheric Imaging Instrument, which includes the Ion and Neutral Camera.
The Magnetospheric Imaging Instrument built by the APL is one of 12 science instruments on the main spacecraft and one of six instruments designed to investigate the space environments around Saturn and its moons. Cassini will begin orbiting Saturn on July 1, 2004, and release its piggybacked Huygens probe about six months later for descent through the thick atmosphere of the moon Titan. Cassini-Huygens is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., manages the mission for NASA's Office of Space Science, Washington. JPL is a division of the California Institute of Technology in Pasadena, Calif.
NEW! This remarkable calendar features stunning images of planets, stars, gaseous nebulae, and galaxies captured by NASA's orbiting Hubble Space Telescope .
U.K. & WORLDWIDE STORE
Stunning posters featuring images from the Hubble Space Telescope and world-renowned astrophotographer David Malin are now available from the Astronomy Now Store.
U.K. & WORLDWIDE STORE