Jupiter moon has 'ocean' of molten rock
Volcanoes believed to draw energy from the Jupiter's gravity as Io rotates around the gas giant.
Thu, May 12, 2011 at 04:46 PM
IO ERUPTS: Acquired during Galileo's ninth orbit around Jupiter, shows two volcanic plumes on Io. One plume was captured on the bright edge of the moon (see inset at upper right), erupting over a caldera. The second plume is near the dark side of Io. (Pho
WASHINGTON — A moon of Jupiter is the only place other than Earth in our solar system where volcanoes occur, and scientists have found an ocean of magma beneath its surface that feed its potent eruptions.
Io is the most volcanic object known in the solar system, producing 100 times more lava than Earth, and data from NASA's Galileo spacecraft has shed new light on how that happens, said the study out Thursday in the journal Science.
A vast ocean of molten rock, known as magma, lies about 20-30 miles (30-50 kilometers) under the Jupiter moon's crust.
"The blistering temperature of the magma ocean probably exceeds 1,200 degrees Celsius (2,200 degrees Fahrenheit)," NASA said in a statement.
The volcanoes were first discovered in 1979 by NASA's Voyager spacecraft, and they are believed to draw energy from the "squeezing and stretching of the moon by Jupiter's gravity as Io orbits the immense planet," NASA said.
According to lead author of the study, Krishan Khurana, the magma ocean is "millions of times better at conducting electricity than rocks typically found on the Earth's surface."
"Scientists are excited that we finally understand where Io's magma is coming from and have an explanation for some of the mysterious signatures we saw in some of Galileo's magnetic field data," said Khurana, a research geophysicist with University of California, Los Angeles.
"Just like the waves beamed from an airport metal detector bounce off metallic coins in your pocket, betraying their presence to the detector, Jupiter's rotating magnetic field continually bounces off the molten rocks in Io's interior."