Juno's close pass of Europa on September 29 (1036 UTC) took it within 352 kilometers of the icy moon, marking the third close pass in history below 500 kilometers. The encounter saw the spacecraft come within a single kilometer of Galileo's 351 kilometers from the surface back in January of 2000, and it provided the opportunity for Juno to use its JunoCam to home in on a region north of Europa's equator. Note the high relief of terrain along the terminator, with its ridges and troughs starkly evident. Image: The complex, ice-covered surface of Jupiter's moon Europa was captured by NASA's Juno spacecraft during a flyby on Sept. 29, 2022. At closest approach, the spacecraft came within a distance of about 352 kilometers. Credit: NASA/JPL-Caltech/SWRI/MSSS. This first image from JunoCam captures features at the region called Annwn Regio, and was collected in the two-hour window available to Juno as it moved past Europa at 23.6 kilometers per second. What we hope to gain from analysis of...

As the Europlanet Science Congress (EPSC) has just wrapped up in Spain’s Palacio de Congresos de Granada, I’m reminded how little time I’ve had recently to keep up with such gatherings. I do hope to have some entries on EPSC-announced findings in the near future. Today I simply note the news of an unexpected ‘heat wave’ (700?) extending 130,000 kilometers just below Jupiter’s northern aurora, one traveling at high speed toward the equator, as announced by James O’Donoghue at the EPSC. Says JAXA’s O’Donoghue: “While the auroras continuously deliver heat to the rest of the planet, these heat wave ‘events’ represent an additional, significant energy source. These findings add to our knowledge of Jupiter’s upper-atmospheric weather and climate, and are a great help in trying to solve the ‘energy crisis’ problem that plagues research into the giant planets.” I mention this work in particular because of my interest in the EPSC results but also because Jupiter has been on my mind thanks to...

We're in that earliest phase of interstellar exploration that is all about nudging outward from our system into the local interstellar medium. That has already involved the Voyagers, but my plan is to keep checking in on both the Interstellar Probe concept at the Johns Hopkins Applied Physics Laboratory and the SGL probe study steadily maturing at the Jet Propulsion Laboratory. These are absorbing ventures as scientists figure out ways to do propulsion, in-flight maintenance (and in the case of SGL, in-flight assembly) and data return on timescales the Voyager team wasn't imagining when those doughty craft were launched in 1977. Nudging outward. Let's check in a bit with New Horizons, because here we have a Kuiper Belt explorer that is fully operational, and with instruments specifically designed for the environment it explores, now some 54 AU from the Sun. It's striking to think that the Juno mission is ten times closer to our star than New Horizons. The Pluto/Charon flyby seems a...

The new Jupiter photos from JWST's Near Infrared Camera (NIRCam) are unusual, enough so that I decided to fold one into today's post. It's a pretty good fit because I had already put together most of the material I was going to use about Europa. It would have been an additional plus if Europa showed up in the image below, but even without it, note that we can see moons as small as Adrasta here. Imke de Pater (UC-Berkeley), who led the observations, noted that both tiny satellites and distant galaxies show up in the same image. And here's Thierry Fouchet, a professor at the Paris Observatory, who likewise worked on the observing effort: "This image illustrates the sensitivity and dynamic range of JWST's NIRCam instrument. It reveals the bright waves, swirls and vortices in Jupiter's atmosphere and simultaneously captures the dark ring system, 1 million times fainter than the planet, as well as the moons Amalthea and Adrastea, which are roughly 200 and 20 kilometers across,...