Southwest Research Institute scientists thrilled by Juno’s Europa images

NASA’s Juno mission has thrilled scientists with new information coming from Europa, one of Jupiter’s moons. It’s been theorized that there is an ocean that could possibly harbor life under a sheet of ice on Europa. Juno was able to snap a small set of high resolution photos of the moon’s surface. TPR’s Jerry Clayton recently spoke with Scott Bolton, who is the Juno principal

This interview has been edited and condensed for clarity

Clayton: Can you give us a brief overview of the Juno mission?

Bolton: Juno was launched in 2011 and it arrived at Jupiter in 2016 and it went into a unique orbit that’s over the poles of Jupiter. So it’s the first spacecraft to actually go over the South and North Pole in its orbits.

It finished its prime mission last year in 2021, and that was to map out over 32 orbits of Jupiter to understand its composition, interior structure and polar magnetosphere, and look into the atmosphere deep below the cloud tops for the first time.

And we completed that last year and went into an extended mission at the end of the summer that included these close flybys of the Galilean satellites and also will eventually allow us to investigate the rings of Jupiter.

Clayton: And what do these most recent images of Europa show?

Bolton: We flew by Europa just the other day actually, and we were really close and we were going really fast. So in just a few minutes we got a lot of data and included some special images from our color camera called Junocam, which was able to get about a kilometer resolution on Europa, which is in a region that wasn’t well imaged before.

So we were able to really see some details of parts of Europa that we hadn’t been able to see before. And we also have a special camera that’s actually used to look at stars, and so it’s special for low light and it took a picture at very high resolution, right at closest approach, just a couple of hundred meters.

And that was on the nightside, because it was looking at Jupiter shine. So there’s a couple of images. Some are the dayside and we have one image of the nightside.

Clayton: And I guess the big question, do these images show any evidence of water?

Bolton: Well, we’re not sure. We’re still interpreting that. But there are some that believe that some remnants of water might show up as dark regions. And we certainly see those.

And the reason is, is that if there was water that was salty and it came and touched the surface at some point and evaporated or sunk back in or disappeared, that it might leave a residue that would then get hit by radiation from Jupiter’s magnetosphere and that might turn some of the salts or different materials dark.

And we certainly see some of that. We did not see any evidence of plumes which have been hypothesized to exist there where you have, you know, geysers are shooting up out of the ice with water. We didn’t see any any evidence of that.

Clayton: Is it going to take more time to process these photos and understand what you’re seeing?

Bolton: Absolutely. I mean, we’re just beginning we’re just taking a look at them and are amazed that the details that we can see. We can see shadows and structure. You can see where ridges are.

And especially one of the images, part of the image is right near the terminator. So if you take your binoculars and you look at the moon, the best place to look is along the day night border, what we call the terminator, because you see the hills, you see the terrain in the shadows, and that’s what we see on Europa.

So we can we can see some of that. But it’s going to take a while for us to figure out what we’re seeing and then compare it to our other data. We have a lot of instruments besides the imaging, and one of them actually looks at the ice at various depths.

And so we’re going to try to understand if we can figure out the structure of the ice. And, you know, we see the Europa looks very cracked and fractured and that may represent itself inside the ice as well.