Juno offers aerial views of a mountain and lava lake on Io

April 19 () –

Data from recent flybys of Io obtained by the NASA Juno mission have been turned into animations that highlight two spectacular features of the Jovian moon: a mountain and a lava lake.

Other recent scientific results from the solar-powered spacecraft include updates on Jupiter's polar cyclones and the abundance of water.

The new findings were presented by Juno principal investigator Scott Bolton during a press conference at the European Geophysical Union General Assembly in Vienna.

Juno performed extremely close flybys of Io in December 2023 and February 2024, approaching within about 1,500 kilometers of the surface, obtaining the first close-up images of the northern latitudes of the moon.

THERE ARE AREAS AS SMOOTH AS GLASS

“Io is just full of volcanoes and we've caught some of them in action,” Bolton said. it's a statement. “We also got excellent close-ups and other data on a 200-kilometer-long lava lake called Loki Patera. There are amazing details showing islands embedded in the middle of a potentially magma lake rimmed with hot lava. The specular reflection our instruments recorded of the lake suggests that parts of Io's surface are as smooth as glass, reminiscent of obsidian glass created volcanically on Earth.”

Maps generated from data collected by Juno's Microwave Radiometer (MWR) instrument reveal that Io not only has a relatively smooth surface compared to Jupiter's other Galilean moons, but it also has poles that are colder than the middle latitudes.

NORTH POLE OF JUPITER

During Juno's extended mission, the spacecraft flies closer to Jupiter's north pole with each pass. This change in orientation allows the MWR instrument to improve its resolution of Jupiter's north polar cyclones. The data allows comparisons of multiple wavelengths of the poles, which reveals that not all polar cyclones are the same.

“Perhaps the most striking example of this disparity can be found in the central cyclone at Jupiter's north pole,” he said. it's a statement Steve Levin, Juno project scientist at NASA's Jet Propulsion Laboratory in Southern California. “It is clearly visible in both infrared and visible light images, but its microwave signature is not as strong as other nearby storms. This tells us that its underground structure must be very different from that of these other cyclones. “The MWR team continues to collect more and better microwave data with each orbit, so we anticipate developing a more detailed 3D map of these intriguing polar storms.”

One of the mission's main scientific goals is to collect data that can help scientists better understand the abundance of water on Jupiter. To do this, the Juno science team is not looking for liquid water. Instead, they seek to quantify the presence of oxygen and hydrogen molecules (the molecules that make up water) in Jupiter's atmosphere. An accurate estimate is essential to putting together the puzzle of the formation of our solar system.

Jupiter was probably the first planet to form and contains most of the gas and dust that did not enter the Sun. The abundance of water also has important implications for the gas giant's meteorology (including how wind currents flow on Jupiter) and its internal structure.

In 1995, NASA's Galileo probe provided a preliminary set of data on the abundance of water on Jupiter during the spacecraft's 57-minute descent into the Jovian atmosphere. But the data created more questions than answers, indicating that the gas giant's atmosphere was unexpectedly hot and, contrary to what the computer models had indicatedlacking water.

“The probe did amazing science, but its data was so far removed from our models of water abundance on Jupiter that we considered whether the location where it sampled might be an outlier. But before Juno, we couldn't confirm it“Bolton said. “Now, with recent results obtained with MWR data, we have determined that the abundance of water near Jupiter's equator is approximately three to four times the solar abundance compared to hydrogen. “This definitively demonstrates that the Galileo probe's entry site was an abnormally dry, desert-like region.”

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

Data obtained during the remainder of Juno's extended mission may help, as it will allow scientists to compare Jupiter's water abundance near the polar regions with the equatorial region and shed 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 16,500 kilometers of the moon's surface. It will make its 61st flyby of Jupiter on May 12.