NASA discovers an underground ocean on Jupiter’s largest moon

Mar 24, 2015

Image credit: NASA, ESA and A. Feild

By Rachel Feltman

NASA announced evidence on Thursday that Jupiter’s largest moon, Ganymede, has a saltwater ocean under its icy surface. The ocean seems to have more water than all the water on Earth’s surface, according to new Hubble observations.

Scientists estimate that the ocean is 60 miles thick, which is about 10 times deeper than Earth’s oceans. But unlike our salty waters, Ganymede’s ocean is buried under 95 miles of ice.

While scientists have speculated since the 1970s about the presence of an ocean on Ganymede — the largest moon in our solar system — until now the only observational evidence came from a brief flyby by the Galileo spacecraft, which didn’t observe the moon long enough to confirm a liquid ocean.

“This discovery marks a significant milestone, highlighting what only Hubble can accomplish,” John Grunsfeld, assistant administrator of NASA’s Science Mission Directorate at NASA Headquarters, said in a statement. “In its 25 years in orbit, Hubble has made many scientific discoveries in our own solar system. A deep ocean under the icy crust of Ganymede opens up further exciting possibilities for life beyond Earth.”


Read the full article by clicking the name of the source located below.

10 comments on “NASA discovers an underground ocean on Jupiter’s largest moon

  • I put this link on the “alien-search-wont-doom-planet-earth-say-scientists-who-want-to-contact-et/” discussion.

    http://www.bbc.co.uk/news/science-environment-31855395

    Ganymede is just one of a large list of objects in the Solar System now thought to hide an ocean deep below the surface. These include the dwarf planets Pluto and Ceres; other Jupiter moons – Europa and Calisto; Saturn’s moons Enceladus, Titan and Mimas; and possibly Neptune’s moon, Triton.



    Report abuse

  • From Wikepedia: Galileo (spacecraft) arrived at Jupiter on December 7, 1995…The data Galileo collected supported the theory of a liquid ocean under the icy surface of Europa, and there were indications of similar liquid-saltwater layers under the surfaces of Ganymede and Callisto. Ganymede was shown to possess a magnetic field

    From Article Titled Above: “NASA discover’s an underground ocean on Jupiter’s largest moon”
    NASA announced evidence on Thursday (March, 2015) that Jupiter’s largest moon, Ganymede, has a saltwater ocean under its icy surface. The ocean seems to have more water than all the water on Earth’s surface, according to new Hubble observations.

    The Washington Post “reports” an old discovery going back 20 years sensationalized to appear ‘new’ in order to attract and mystify ignorant readers. The significant findings of recent Hubble observations add crucial detailed data confirming the layered structure of the moons, a structure known for decades as illustrated concentrically in the diagram. Layman readers should not be dazzled or awestruck into believing otherwise. Any microbial life which may have developed (and survived) in parts of this huge ocean that made its way toward the surface through cracks in the ice would have been fatally irradiated by Jupiter’s radiation. Though a finer point, the term “underground” ocean is misleading. The thin saline ocean lies under a 60 mile ice crust which rests on a thick ice mantle. “Ground,” the rocky mantle is not reached for over 200 miles below the surface



    Report abuse

  • Melvin Mar 25, 2015 at 4:01 am

    The Washington Post “reports” an old discovery going back 20 years sensationalized to appear ‘new’ in order to attract and mystify ignorant readers.

    The additional significant findings are vast, in comparison to the superficial view of an icy crust in the initial flyby.

    The significant findings of recent Hubble observations add crucial detailed data confirming the layered structure of the moons, a structure known for decades as illustrated concentrically in the diagram.

    While the layered structure is typical of planets, the details have certainly not “been known for decades”.

    Though a finer point, the term “underground” ocean is misleading. The thin saline ocean lies under a 60 mile ice crust which rests on a thick ice mantle. “Ground,” the rocky mantle is not reached for over 200 miles below the surface.

    Earth-bound notions, such as “ground”, “atmosphere”, and “rock”, need to be rethought, when dealing with other planets.
    In the the outer Solar-System, water is usually a rock, carbon-dioxide can be a solid, methane may be a sea or rain, hydrogen may be a solid core of a planet, nitrogen may be a liquid, and volcanoes may erupt water and ice.
    On large exoplanets ice can be hot!



    Report abuse

  • When considering the scale of oceans, consider the Earth as a six foot diameter polished sphere. Breathing on the surface of the sphere, the vapor deposited on that six foot sphere is the same relative depth as our oceans. Place a single sheet of paper on the sphere, that is the relative depth of the atmosphere. When considering the depth of the water/ice on Ganymede; fascinating.



    Report abuse

  • The additional significant findings are vast, in comparison to the superficial view of an icy crust in the initial flyby.

    I agreed when I said, “The significant findings of recent Hubble observations add crucial detailed data confirming the layered structure of [Gannymede],…” Still the article said nothing that has not been said before about Ganymede. Implying that the data collected by Galileo was superficial, tenuous and speculative conveys disingenuous overreach : “the only observational evidence came from a brief flyby by the Galileo spacecraft, which didn’t observe the moon long enough to confirm a liquid ocean.” Not so. Scientists have “known” beyond a reasonable doubt for decades that vast oceans exist on Jupiter’s moons beneath the ice crust, notably Europa and Ganymede.

    Readers are mislead, I believe, for two related reasons 1) Author Rachel Feltman sensationalizes her story to entice general readers to read all about a jaw-dropping discovery which surmises that Jupiter’s moon[s] are hospitable to life with oceans just like those on Earth. Besides advancing the Washington Post’s interests, she also uses the article to promote NASA agendas for further outer-planet explorations at exorbitant expense with inflated budgets and cost overruns….“A deep ocean under the icy crust of Ganymede opens up further exciting possibilities for life beyond Earth.”…Scientists have already confirmed the existence of an ocean on Europa, another moon orbiting Jupiter, and NASA has announced plans to send an unmanned mission there searching for the life that might come with liquid water.

    Tens, perhaps hundreds of billions of dollars would have to be spent. Wherever the submarine probe happened to land on the gargantuan moon, it would have to bore through unknown thousands of meters of ice to reach the saline ocean. If no life were found close to the ocean surface or deeper where the probe broke through, billions would go down the drain but comprehensive exploration of the vast ocean areas and depths would require additional submarine exploration running into trillions of dollars.

    Inflaming the public imagination with misleading claims and dreams of giant squids swimming in celestial oceans, could misdirect precious resources from NASA’s limited budget better allocated to currently feasible productive explorations, notably Mars. Distant Ganymede can wait.



    Report abuse

  • It looks like we are about to get detailed information on another Solar-System body!

    http://www.bbc.co.uk/news/science-environment-32311907
    The New Horizons probe, which is bearing down on Pluto, has captured its first colour image of the distant dwarf planet.

    The picture, just released by the US space agency, shows a reddish world accompanied by its biggest moon, Charon.

    New Horizons is set to barrel past Pluto on 14 July.

    It will acquire a mass of data that it will then return to Earth very slowly over the course of the next 16 months.



    Report abuse

Leave a Reply

View our comment policy.