Close-Up Photo of Jovian Moon Shows Lava
The first high-resolution picture of Jupiter’s moon Io, taken by the Galileo probe on an Oct. 10 fly-by, was released Friday by the Jet Propulsion Laboratory and NASA.
The close-up picture of the moon, taken from a height of 417 miles, shows a lava field near the center of the erupting volcano Pillan. The resolution of the picture is 50 times better than that of the previous best pictures, taken in 1979 by the Voyager spacecraft.
In 1997, Galileo caught Pillan in the process of erupting--albeit from a much greater distance. The explosion blanketed an area 250 miles in diameter with ash.
The lava that is still flowing from Io is hotter than any that has flowed on Earth in the last 2 billion years, project researchers said.
The area photographed is 4.5 miles long and 1.4 miles wide, and reveals features as small as 30 feet in diameter. A complex mix of smooth and rough areas--with clusters of pits and domes, many the size of houses--can be seen. Galileo scientists estimate that the cliff on the left side of the image ranges from 10 to 33 feet high.
The Io images captured by Galileo’s primary camera were not as good as scientists had hoped because intense radiation from the radiation belts surrounding Jupiter damaged it, said Galileo project manager Jim Erickson. Better images, including the one released Friday, were available from other cameras, however.
An even closer fly-by of Io is scheduled for Nov. 25, when Galileo will swoop to an altitude of 186 miles.
Galileo was launched 10 years ago last Monday, reaching Jupiter in December 1995 after flying past Venus once and Earth twice. It has spent the last two years studying Jupiter, its moons and the magnetic environment. The close fly-bys of Io were scheduled for the end of the mission because of the risk of damage from the intense magnetic fields to be encountered during the sweeps.
The new photo, and others as they become available, can be viewed on the Internet at www.jpl.nasa.gov/pictures/io. Background information about the mission is available atgalileo.jpl.nasa.gov.
