Two giantplumes erupted recently on Jupiter, moving faster than any other Jovian featureand leaving global streaks of red cloud particles in their wake.
New analysesof the March 2007 outbursts suggest internal heat plays a significant role ingenerating such weather patterns.
Theresults, detailed in the Jan. 24 issue of the journal Nature, shed lighton the inner workings of Jupiter'sweather. Planetary scientists and meteorologists have puzzled over whetherinternal heat or sunlight (or both) powers Jupiter's stormy disturbances andjets.
A team ofastronomers monitored the development of the cloud activity in March 2007 usingNASA's Hubble Space Telescope, the NASA Infrared Telescope Facility in Hawaiiand telescopes in Spain's Canary Islands.
The chemical makeup and formation of these red aerosols is a bit of a mystery itself. "Nobody knows what its composition is," said lead study author Agustin Sanchez-Lavegaof Universidad del Pais Vasco in Spain, "although in the Jovian atmosphereit is seen in the Great Red Spot and other smaller vortices," he told SPACE.com.
Using theirobservations and computer models, the astronomers found the bright plumesformed in Jupiter's deep water clouds and then shot ice particles and waterwell above the visible clouds.
"Theinfrared images distinguish the plumes from lower-altitude clouds and show thatthe plumes are lofting ice particles higher than anyplace else on theplanet," said study researcher Glenn Orton of NASA's Jet PropulsionLaboratory in Pasadena, Calif.
Theresearchers also found that despite the turmoil created as the plumes churnedthrough the jet stream, once the plumes waned, the planet's jet stream remainednearly unchanged. This observation, along with computer models, suggests thejet stream extends more than 62 miles (100 kilometers) below the cloud topswhere most sunlight gets absorbed.
Sincesunlight is minimal there, the researchers say the results support the ideathat Jupiter's jets are powered by internal heat. This hypothesis was firstproposed based on 1995 observations made when the Galileo probe descendedthrough Jupiter?supper atmosphere.
That'sunlike what happens on Earth, where sunlight drives all weather. But for theouter planets, where the sun's reach can be minimal, a planet's internal heatmight play a substantial role. At the extreme, distant Neptune releases twiceas much heat as it takes in from sunlight, and it boasts winds reaching 1,500 mph(about 2,400 kph). The release of heat is part of the natural cooling of aplanet, a process that begins at birth when a planet is at its hottest.
?All theevidence points to a deep extent for Jupiter's jets and suggest that theinternal heat power source plays a significant role in generating thejet," Sanchez-Lavega said.
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