![]() ![]() Juno's Jovian InfraRed Auroral Mapper instrument was designed primarily to study the stunning light shows in Jupiter's atmosphere, known as auroras. NASA's Juno mission is focused mainly on Jupiter, specifically to unveil the secrets of its little-understood polar region, as well as to probe its deep interior and even its core. Juno collected the data last December, when the spacecraft passed within 290,000 miles of Io-a bit farther than the distance from Earth to our own moon. (NASA/JPL-Caltech)ĭata from Juno revealed the newest volcano as a previously undetected heat source near Io's southern pole. Infrared image of Jupiter's moon Io, captured by Juno's JIRAM instrument, showing the newly discovered volcanic hot-spot amid a host of others. Scientists believe there may be as many as 250 more that remain undiscovered, and this latest hot-spot has scientists eagerly anticipating future, closer flybys of Io, a moon just slightly larger than Earth's own. ![]() Since the Voyager spacecraft, and later Galileo, began collecting data in the Jupiter system in the 1970's and 1980's, about 150 active volcanoes have been spotted on Io. "We would love to be able to place seismometers on Io and measure the quakes to determine the interior but we just don't have that available to us at the moment.NASA's Juno spacecraft may have discovered another volcano on Jupiter's moon Io, adding to an already impressive list of known active volcanoes there. This time they've used the technique to study a hot volcanic world."Īccording to Brown studying the interaction between a moon and the host planet's magnetic field is the best available way of determining that moon's internal composition. The big difference is they're all relatively cold, icy moons. "That's something which has been done previously with the Jovian moons Europa, Ganymede and Callisto. "By showing how Io deflects Jupiter's magnetic field, Khurana and colleagues are inferring new data about this moon's internal structure," says Brown. A different way of doing scienceĭr Michael Brown, an astronomer at Melbourne's Monash University, says the research is intriguing. ![]() This is surrounded by a thick mantle most likely composed of the igneous minerals peridotite and forstenite, both containing magnesium and olivine. They conclude Io's mantle is too hot to effectively cool its core, which has remained molten and explains why the moon doesn't generate a powerful magnetic field.Ĭombined with previous gravity studies, Khurana and colleagues paint a picture of Io having a molten metallic iron core with a radius of up to 950 kilometres. Surface lava temperatures hint at an upper mantle temperature of up to 1450☌. The researchers say the global, subsurface magma layer of the mantle must be over 50 kilometres thick and is kept partially molten by tidal forces. They also assumed Io's overall composition started out similar to chondritic meteorites, before separating into geological layers during its formation. Khurana and colleagues modelled the mantle's electrical properties on examples found in the Earth's upper mantle. Reporting in the journal Science, the researchers claim magnetometer data collected by Galileo, found Io's inductive response suggests a vast, electrically conductive reservoir of magma beneath the crust. In the absence of seismometers and other direct sensing devices, they used Jupiter's magnetic field as a sounding signal. Now a re-analysis of magnetic field data from NASA's Galileo spacecraft by Dr Krishan Khurana from the University of California, Los Angeles and colleagues has provided evidence of a huge magma ocean inside Io. The extent of this melting has been a long-standing subject of debate. ![]() Io is the most volcanic place in the solar system, constantly torn by gravitational tidal forces from Jupiter generating enough heat through friction to melt the moon's interior. Liquid centre Scientists say a global magma ocean lies just under the thin volcano and lava covered crust of the Jovian moon Io. Jupiter's moons act like shepherds, Science Online,.Stormy Jupiter reveals more secrets, Science Online,.NASA confirms Jupiter smash, Science Online,. ![]()
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