A NASA teleconference today shared some exciting news about Jupiter's moon Europa. And no, it doesn't involve aliens. Instead, this announcement was all about some interesting activity that may be happening on Europa's surface, which good old Hubble recorded.
The pictures show what appears to be water vapor erupting from the surface of Europa. NASA has shared numerous images, including composites made from data collected by the Hubble telescope and the Galileo and Voyager missions.
NASA's scientists were careful to phrase their findings as possibilities. That is, the images we have suggest water vapor plumes, but it could be that what we're seeing are artifacts in the images themselves. But if the interpretation is correct, the pictures tell us that the water vapor eruptions are intermittent.
We know this because Europa is tidally locked with Jupiter, meaning the same side of Europa always faces the planet. That also means we're always looking at the other side of Europa. But not all the photos of Europa have evidence of water vapor plumes. That means the moon isn't constantly ejecting water; rather it's something that happens occasionally.
Assuming water vapor is erupting from Europa, that's great news for future missions. It means that we'll have an easier time analyzing the contents of the water for traces of organic material without having to actually drill down through the icy surface to get to the ocean beneath. There's no guarantee we'll discover evidence of life in the water vapor, but it's a promising possibility.
So what is the mechanism that forces water from the subterranean ocean to erupt from the surface? We're not sure, but we have a few ideas. It's possible that water from the underground ocean itself could be forced through Europa's ice shell to erupt on the surface. Tidal forces would push the water through cracks. An alternative hypothesis suggests that the water vapor might originate within the ice itself, not directly from the ocean underneath.
NASA plans to send a mission to Europa to get an up-close look at the moon in the future. We also may employ future telescopes, like the James Webb Space Telescope, to study Europa and other bodies within our solar system. Perhaps then we'll be able to answer a few more questions we have regarding the mysterious moon and its underground oceans.
On a related note, as I listened to NASA's press conference this afternoon, I couldn't help but reimagine Rutger Hauer's famous speech at the end of "Blade Runner": "I've seen things you people wouldn't believe — attack ships on fire off the shoulders of Orion, water vapor erupting off the surface of Europa."