New And Valuable Data, On The Solar System's Most Extreme "Fire And Ice" Moon -- Way Out, At Io -- Courtesy Juno's Extended Mission Fly-Bys...

This all is due to the fact that the Biden administration authorized spending at NASA on an extended mission, for Juno. The speedy, twisty, copper colored craft was performing flawlessly, and so most of the added expense was just keeping great scientists on-board, here on Earth to direct operations, and monitor progress -- remotely. Very. . . remotely (at 400 million to 600 million miles out there -- into the night skies).

“Io provides a unique window into learning how tidal heating works throughout the cosmos, a fundamental process that provides energy and heat to worlds that are far from their parent star,” according to Scott Bolton, the study's coauthor and Juno’s principal investigator at Southwest Research Institute -- in San Antonio. Here's the latest, from NASA/JPL:

. . .NASA’s Juno mission has provided the first measurements of the temperature below the surface of Jupiter’s moon Io, revealing significant heating within the shallow subsurface of the most volcanically active world in the solar system. Collected during two close flybys, the data also shows that most of Io’s surface is remarkably smooth and composed of material of very low density.

Published Wednesday in the Journal of Geophysical Research: Planets, these findings break new observational ground for both fiery and icy worlds beyond our planet.

Io’s extreme volcanism is powered by tidal heating. The moon is constantly stretched and squeezed by Jupiter’s immense gravity as it travels its slightly elliptical orbit, generating internal heat output many times greater than Earth’s. Until now, virtually everything known about that heat came from infrared observations, which sense only the temperature of the top surface. The latest findings are derived from data collected by the spacecraft’s Microwave Radiometer (MWR) instrument. . . .

Juno’s Microwave Radiometer was designed by Bolton to peer beneath Jupiter’s cloud tops to investigate the dynamics and composition of the gas giant’s deep atmosphere. The MWR’s six microwave antennas serve as a single instrument, simultaneously detecting microwaves at a wide range of wavelengths, from about half an inch to 20 inches (1.3 to 51 centimeters). During the mission’s extended phase, the MWR instrument has provided the opportunity to observe three of the planet’s Galilean moons: Ganymede, Europa, and Io. . . .

“The instrument measured Io’s thermal emission at depths ranging from a few inches down to tens of feet. Everywhere we looked, we found the temperature rising by more than 40 degrees Fahrenheit just several feet into the surface — a gradient far steeper than solar heating alone can explain,” said Shannon Brown, the paper’s lead author at NASA’s Jet Propulsion Laboratory in Southern California. . . .

While Io is not likely a good candidate for sub-surface ocean life, given these extremes -- certainly elsewhere in the Universe, where a smaller but temperate moon is endlessly warmed / heated by the "smushing" of a large planet's gravity -- even if very far from its host star, the moonlet could be a decent candidate for sub-surface water oceans -- and thus. . . life. Grinning widely, now -- as life is likely happening in billions upon billions of settings, throughout the cosmos. . . .

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