NASA originally published this article on June 26, 2024. Edited by EarthSky.
Infrared imagery from the solar-powered Juno spacecraft heats up the dialogue on the interior workings of Jupiter’s hottest moon.
Juno zooms in on volcanic processes at Io
New findings from NASA’s Juno probe present a fuller image of how widespread the lava lakes are on Jupiter’s moon Io. They usually embrace first-time insights into the volcanic processes at work there. These outcomes come courtesy of Juno’s Jovian Infrared Auroral Mapper (JIRAM) instrument which “sees” in infrared gentle.
Researchers published a paper on Juno’s most up-to-date volcanic discoveries on June 20 within the peer-reviewed journal Nature Communications Earth and Surroundings.
Io is actually intriguing
Io has intrigued the astronomers since 1610, when Galileo Galilei first found the Jovian moon. It’s barely bigger than Earth’s moon. Some 369 years later, NASA’s Voyager 1 spacecraft captured a volcanic eruption on the moon. Subsequent missions to Jupiter, with extra Io flybys, found extra plumes … together with lava lakes.
Scientists now consider Io, which is stretched and squeezed like an accordion by neighboring moons and large Jupiter itself, is probably the most volcanically active world within the solar system. However whereas there are a lot of theories on the sorts of volcanic eruptions throughout the floor of the moon, little supporting information exists.
Photos captured in shut flyby
In each Might and October 2023, Juno flew by Io, coming inside about 21,700 miles (35,000 kilometers) and eight,100 miles (13,000 km), respectively. Amongst Juno’s devices getting a superb take a look at the beguiling moon was JIRAM.
Designed to seize the infrared gentle (which isn’t seen to the human eye) rising from deep inside Jupiter, JIRAM probes the climate layer all the way down to 30 to 45 miles (50 to 70 km) beneath the gas giant’s cloud tops. However throughout Juno’s prolonged mission, the mission workforce has additionally used the instrument to review the moons Io, Europa, Ganymede and Callisto. The JIRAM Io imagery confirmed the presence of brilliant rings surrounding the flooring of quite a few sizzling spots.
Alessandro Mura, a Juno co-investigator from the Nationwide Institute for Astrophysics in Rome, stated:
The excessive spatial decision of JIRAM’s infrared photographs, mixed with the favorable place of Juno throughout the flybys, revealed that the entire floor of Io is roofed by lava lakes contained in caldera-like options. Within the area of Io’s floor wherein we’ve got probably the most full information, we estimate about 3% of it’s lined by one in every of these molten lava lakes. (A caldera is a big melancholy fashioned when a volcano erupts and collapses.)
Fireplace-breathing lava lakes
JIRAM’s Io flyby information not solely highlights the moon’s plentiful lava reserves, but in addition supplies a glimpse of what could also be occurring beneath the floor. Infrared photographs of a number of Io lava lakes present a skinny circle of lava on the border, between the central crust that covers many of the lava lake and the lake’s partitions. Recycling of soften is implied by the shortage of lava flows on and past the rim of the lake. Thus, it signifies a steadiness between soften that has erupted into the lava lakes and soften that’s circulated again into the subsurface system.
Mura added:
We now have an concept of what’s the most frequent sort of volcanism on Io: monumental lakes of lava the place magma goes up and down. The lava crust is compelled to interrupt towards the partitions of the lake, forming the everyday lava ring seen in Hawaiian lava lakes. The partitions are possible lots of of meters excessive, which explains why magma is mostly not noticed spilling out of the paterae – bowl-shaped options created by volcanism – and shifting throughout the moon’s floor.
JIRAM information means that many of the floor of those Io sizzling spots consists of a rocky crust that strikes up and down cyclically as one contiguous floor as a result of central upwelling of magma. On this speculation, as a result of the crust touches the lake’s partitions, friction retains it from sliding, inflicting it to deform and finally break, exposing lava slightly below the floor.
One other chance
Nevertheless, another speculation stays in play. Magma is welling up in the course of the lake, spreading out and forming a crust that sinks alongside the rim of the lake, exposing lava.
Scott Bolton, principal investigator for Juno on the Southwest Analysis Institute in San Antonio, stated:
We’re simply beginning to wade into the JIRAM outcomes from the shut flybys of Io in December 2023 and February 2024. The observations present fascinating new info on Io’s volcanic processes. Combining these new outcomes with Juno’s longer-term marketing campaign to watch and map the volcanoes on Io’s never-before-seen north and south poles, JIRAM is popping out to be probably the most beneficial instruments to find out how this tortured world works.
Juno executed its 62nd flyby of Jupiter – which included an Io flyby at an altitude of about 18,175 miles (29,250 kilometers) – on June 13. The 63rd flyby of the gas giant might be July 16.
Backside line: NASA’s Juno spacecraft flew in near Io and studied lava lakes, gleaning new info on the volcanic processes on this lively volcanic moon.
Read more: Juno images of Europa reveal a complex, active surface
