NASA’s Juno Gives Aerial Views of Mountain, Lava Lake on Io

The JunoCam instrument on NASA’s Juno captured this view of Jupiter’
The JunoCam instrument on NASA’s Juno captured this view of Jupiter’s moon Io - with the first-ever image of its south polar region - during the spacecraft’s 60th flyby of Jupiter on April 9.
Jupiter was likely the first planet to form, and it contains most of the gas and dust that wasn’t incorporated into the Sun. Water abundance also has important implications for the gas giant’s meteorology (including how wind currents flow on Jupiter) and internal structure.

In 1995, NASA’s Galileo probe provided an early dataset on Jupiter’s water abundance during the spacecraft’s 57-minute descent into the Jovian atmosphere. But the data created more questions than answers, indicating the gas giant’s atmosphere was unexpectedly hot and - contrary to what computer models had indicated Übereft of water.

"The probe did amazing science, but its data was so far afield from our models of Jupiter’s water abundance that we considered whether the location it sampled could be an outlier. But before Juno, we couldn’t confirm," said Bolton. "Now, with recent results made with MWR data , we have nailed down that the water abundance near Jupiter’s equator is roughly three to four times the solar abundance when compared to hydrogen. This definitively demonstrates that the Galileo probe’s entry site was an anomalously dry, desert-like region."

The results support the belief that the during formation of our solar system, water-ice material may have been the source of the heavy element enrichment (chemical elements heavier than hydrogen and helium that were accreted by Jupiter) during the gas giant’s formation and/or evolution. The formation of Jupiter remains puzzling, because Juno results on the core of the gas giant suggest a very low water abundance - a mystery that scientists are still trying to sort out.

Data during the remainder of Juno’s extended mission may help, both by enabling scientists to compare Jupiter’s water abundance near the polar regions to the equatorial region and by shedding additional light on the structure of the planet’s dilute core.

During Juno’s most recent flyby of Io, on April 9, the spacecraft came within about 10,250 miles (16,500 kilometers) of the moon’s surface. It will execute its 61st flyby of Jupiter on May 12.

More About the Mission

NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington. The Italian Space Agency (ASI) funded the Jovian InfraRed Auroral Mapper. Lockheed Martin Space in Denver built and operates the spacecraft.