Jupiter’s moon Io is the most volcanic object in the solar system. There may be as many as 400 — four hundred! On a moon only a little bit bigger than our own! — and 150 are active at any one time. It’s a hellscape there, with sulfur compounds spewed everywhere, a haphazard mix of hot spots from the internal volcanism and the cold landscape due to it being so far from the Sun. 

That distance is an issue for scientists. At best it’s only about 1 arcsecond in size as seen through a telescope, which is small. The full Moon is 1,800 arcseconds across, so Io looks teeny. The only way to see it in any detail is to send spacecraft there. And while that’s great, the problem is they can’t just observe Io whenever scientists want; the craft is usually busy looking at a hundred other things, and you can’t get the time coverage needed to see changes in the landscape due to eruptions.

… until recently. There are some telescopes that can see it pretty well; the Keck 10 meters, for example, are huge telescopes so they have good resolution (ability to see details) and also sports adaptive optics, an internal mechanism that compensates for the distortions due to the roiling atmosphere above our heads that causes stars and small objects to twinkle. However, Keck sees in the infrared, but it helps to be able to see things in visible light, the kind our eyes see.

Enter the Large Binocular Telescope (or LBT), a pair of immense 8.4-meter telescopes mounted side-by-side in Arizona. The combo provides a fantastic view of the heavens, and just got a new instrument called SHARK-VIS. Aside: I searched high and low, and it took a long time to finally find out what the acronym stands for: System for coronagraphy with High order Adaptive optics from R to K band. This unwraps to mean is it has a metal mask to block out bright sources to see faint things near them (the coronagraph), adaptive optics is explained above, and the R and K bands are regions in the infrared spectrum. SHARK-NIR (for near-infrared) was the first camera, and the new one looks in visible light, so it’s SHARK-VIS^*.

A new paper was just published in Geophysical Research Letters about observations of Io, and it features this dynamite image of the moon:

Yowza! All those blotches on it are volcanoes, many of which are active (Io is relentlessly squeezed by Jupiter’s immense tidal force, which create internal friction which melts the moon’s interior and cracks the outer layers, allowing that material to reach the surface). In fact the paper notes that the observations show some changes on the surface. The volcano Pele is the oddly shaped dark blob just below and to the right of center, surrounded by a red ring of erupted material. There are two volcanoes just to the right of it; the left one is Pillan Patera, and the scientists note that the red ring looks overlaid by newer lighter material right where Pillan sits. That’s likely from a powerful eruption that occurred in 2021. 

This image is the highest resolution visible light image taken from Earth of Io, and is better even than what Hubble can do. The scientists hope to get simultaneous observations of Io using LBT and infrared telescope, the latter of which can trace hot spots better. Images in different wavelengths really help planetary scientists get a better grip on the processes going on with the small moon (and, really, with any astronomical object; physical processes are produced by a variety of mechanisms that can reveal themselves in widely different parts of the electromagnetic spectrum).

This image is really tremendous, and I’m excited to see what else this amazing SHARK-VIS camera can do. Being able to monitor Jupiter’s moons, and those of the other outer planets, on a more routine basis could reveal a lot of very interesting behaviors. I’m really looking forward to seeing what else this machine can do.

 ^* NOTE TO SCIENTISTS: Define your danged acronyms in every paper, please.

• In 2018, planetary scientists announced they may have found extant liquid water under a glacier at the Martian south pole. That made quite a splash (haha), since liquid water is what you need for life on Earth. This claim has been examined many times since, and — as usual in science — opinions have gone back and forth. New research just published by a different team of scientists suggests the water isn’t real [link to journal paper]. All of these observations are using radar reflections made by spacecraft; liquid and solid water have different properties and reflect radar differently. The new work shows that different compositions and thicknesses in the ice layers of the glacier can mimic the results of liquid water, and they use fewer assumptions about conditions on Mars as well, making this a simpler explanation. Is it correct? We still don’t know, but for now it looks like the tide may have turned on this particular claim of Martian liquid water.
  

• I recently mentioned how a galaxy at very high redshift is making astronomers rethink how early galaxies (and the stars therein) formed. Another paper has come out reinforcing this idea: deep JWST spectra of a galaxy called GS-z12, only a little bit closer to us than the galaxy mentioned above, reveal the presence of carbon, and hint at neon and oxygen, too. Other aspects of the observations indicate a lot of gas and dust inside the galaxy, too. Given we see this galaxy as it was just 350 million years after the Big Bang, that’s a lot of heavy elements! These types of atoms are created in massive stars, then expelled into space when the stars explode as supernovae. This observation once again shows this process happens faster than we previously thought.

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