Hamilton and his team performed the spatial analysis using a new, global geologic map of Io, produced by David Williams of Arizona State University, Tempe, Ariz., and his colleagues. 1 in Earth and Planetary Science Letters. Hamilton, who is stationed at NASA’s Goddard Space Flight Center in Greenbelt, Md., is lead author of a paper about this research published Jan. “Our analysis supports the prevailing view that most of the heat is generated in the asthenosphere, but we found that volcanic activity is located 30 to 60 degrees east from where we expect it to be,” said Christopher Hamilton of the University of Maryland, College Park. The asthenosphere is where rock behaves like putty, slowly deforming under heat and pressure. Some propose it heats up the deep interior, but the prevailing view is that most of the heating occurs within a relatively shallow layer under the crust, called the asthenosphere. The question remains regarding exactly how this tidal heating affects the moon’s interior. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute In the same way that you can heat up a spot on a wire coat hanger by repeatedly bending it, the flexing creates friction in Io’s interior, which generates the tremendous heat that powers the moon’s extreme volcanism.Ī New Horizons image captures the giant plume from Io’s Tvashtar volcano. The flexing from gravity causes tidal heating. This, in turn, causes Io to flex as it moves around Jupiter.įor example, as Io gets closer to Jupiter, the giant planet’s powerful gravity deforms the moon toward it, and then, as Io moves farther away, the gravitational pull decreases and the moon relaxes. This regular timing means that Io feels the strongest gravitational pull from its neighboring moons in the same orbital location, which distorts Io’s orbit into an oval shape. Io orbits faster than these other moons, completing two orbits every time Europa finishes one, and four orbits for each one Ganymede makes.
Io is caught in a tug-of-war between Jupiter’s massive gravity and the smaller but precisely timed pulls from two neighboring moons that orbit farther from Jupiter - Europa and Ganymede. Galileo, which was also a JPL mission, flew by Io in 19. Voyager, still being managed by JPL, discovered Io’s volcanoes in 1979, making that moon the only body in the Solar System other than Earth known to have active magma volcanoes. The new paper also analyzes data from other spacecraft and ground-based telescopes, but much of what scientists know about Io’s surface comes from these two missions. The team, which includes Rosaly Lopes of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., primarily used data from NASA’s Voyager and Galileo missions. Image Credit: NASA/JPL/University of Arizona This global view of Jupiter’s moon, Io, was obtained during the tenth orbit of Jupiter by NASA’s Galileo spacecraft. However, concentrations of volcanic activity are significantly displaced from where they are expected to be, based on models that predict how the moon’s interior is heated, according to NASA and European Space Agency researchers. Jupiter’s moon Io is the most volcanically active world in the Solar System, with hundreds of volcanoes, some erupting lava fountains up to 250 miles high (about 400 kilometers).
0 kommentar(er)
