How Warm Are the Oceans on the Icy Moons? The Ice Thickness Provides a Clue.

Jupiter's moon Ganymede is the largest moon in the Solar System and may have an ocean sandwiched between two layers of ice. But how warm is that ocean? Image Credit: By National Oceanic and Atmospheric Administration Public Domain, https://commons.wikimedia.org/w/index.php?curid=8070396

Scientists are discovering that more and more Solar System objects have warm oceans under icy shells. The moons Enceladus and Europa are the two most well-known, and others like Ganymede and Callisto probably have them too. Even the dwarf planet Ceres might have an ocean. But can any of them support life? That partly depends on the water temperature, which strongly influences the chemistry.

We’re likely to visit Europa in the coming years and find out for ourselves how warm its ocean is. Others on the list we may never visit. But we may not have to.

Continue reading “How Warm Are the Oceans on the Icy Moons? The Ice Thickness Provides a Clue.”

Mini-Subs Could One Day Ply the Seas Under Europa’s Ice

This is a model of the miniature underwater vehicle being developed at MARUM with partners from industry. It will have a diameter of around ten cm and a length of about 50 cm. The tiny submarines will be placed inside a melt probe then released in the subglacial lakes under Antarctica. Image Credit: MARUM – Center for Marine Environmental Sciences, University of Bremen.

The most promising places to look for life in the Solar System are in the ocean moons Europa and Enceladus. But all that warm, salty, potentially life-supporting water is under thick sheets of ice: up to 30 km thick on Europa and up to 40 km thick for Enceladus.

The main obstacles to exploring all that water are the thick ice barriers. Assuming a spacecraft can be designed and built to melt its way through all that ice, what then?

Submarines can do the actual exploring, and they needn’t be large.

Continue reading “Mini-Subs Could One Day Ply the Seas Under Europa’s Ice”

Comet Impacts Could Have Brought the Raw Ingredients for Life to Europa’s Ocean

An artist's concept of a comet or asteroid impact on Jupiter's moon Europa. Credit: NASA/JPL-Caltech

Jupiter is the most-visited planet in the Solar System, thanks largely to NASA. It all started with Pioneer 10 and 11, followed by Voyager 1 and 2. Those were all flyby missions, and it wasn’t until 1996 that the Galileo spacecraft became the first to orbit the gas giant and even send a probe into its atmosphere. Then in 2016, the Juno spacecraft entered orbit around Jupiter and is still there today.

All of these missions were focused on Jupiter, but along the way, they gave us tantalizing hints of the icy moon Europa. The most impactful thing we’ve learned is that Europa, though frozen on the surface, holds an ocean under all that ice. And that warm, salty ocean might contain more water than all of Earth’s oceans combined.

Might it hold life?

Continue reading “Comet Impacts Could Have Brought the Raw Ingredients for Life to Europa’s Ocean”

Even Tiny Mimas Seems to Have an Internal Ocean of Liquid Water

Mimas, as imaged by NASA's Cassini spacecraft and processed by @kevinmgill

Data from the Cassini mission keeps fuelling discoveries. The latest discovery is that Saturn’s tiny moon Mimas may have an internal ocean. If it does, the moon joins a growing list of natural satellites in our Solar System that may harbour liquid water under their surfaces.

Continue reading “Even Tiny Mimas Seems to Have an Internal Ocean of Liquid Water”