back to article Launching soon: ESA's Juice to probe Jupiter's moons for signs of possible life

On December 4, 1973, NASA's Pioneer 10 became the first spacecraft to observe Jupiter up close, zipping by some 82,000 miles above the alien world's swirling clouds. Its twin probe, Pioneer 11, followed a year later, coming within a third of that distance to the gas giant. Now the European Space Agency is about to try for an …

  1. jmch Silver badge

    Goldilocks zone?

    Thumbs-up for all the excellent science-y stuff. Interesting to see if Ganymede has lots of liquid water, that plus a magnetosphere are 2 very strong reasons for life being sustainable on Earth. But surely it's quite a way out of the "Goldilocks zone" to be able to get much solar power, so any potential future human habitation would need to be nuclear-powered.


    "Shaped like a washing machine with huge solar panel wings, Juice will be... "

    So it's in the shape of a cube, but you somehow think we can't visualise a cube and would find it easier to visualise a washing machine??? Weird!!! Unless the point is that it's the *size* of a washing machine??

    1. Joe W Silver badge

      Re: Goldilocks zone?

      Also: "three times closer" and "25 times weaker". Sounds really weird, as I would use "times" with things that are bigger / longer /stronger... This way around it has the effect of fingernails on the blackboard of my soul.

      Yes, the science sounds really cool, I wish them luck!

      1. diodesign (Written by Reg staff) Silver badge

        Closer etc

        OK, we're clarified or taken those out since they were confusing some people.


        1. druck Silver badge

          Re: Closer etc

          Please don't let them in, in the first place. We've seen these confusing inverted comparisons in many articles since the scourge of usaification.

    2. Charlie Clark Silver badge

      Re: Goldilocks zone?

      These are not considered habitable, yet. But important places to look for evidence as to whether life on earth is unique. In the distant future, these could be habitats when the Sun expands and consumes our home. In the meantime, capturing some of the energy from Jupiter's "squeezing" would be as important as anything else: geothermal energy on steroids! ;-)

    3. Wellyboot Silver badge

      Re: Goldilocks zone?

      Yes, very similar to Earth with just a lower solar energy input, If there’s detectable life in the Ganymede ocean we’ll really want to know how the replication function is carried out, RNA/DNA or some completely different process more tolerant to ionizing radiation. That’ll be quite the fishing trip.

      1. Anonymous Coward
        Anonymous Coward

        Re: Goldilocks zone?

        RNA/DNA or some completely different process more tolerant to ionizing radiation

        A few metres of water make a very good radiation shield (hence its use in storage pools for nuclear reactor radioactive waste) so I'd be surprised if radiation damage to genetic material was an issue.

    4. diodesign (Written by Reg staff) Silver badge

      'So it's in the shape of a cube'

      Well, yeah, it really does look like a washing machine, but it's not washing machine sized. It's much bigger.

      When simply stowed, it's 4.09 x 2.86 x 4.35 m.


      1. Lars Silver badge
        Thumb Up

        Re: 'So it's in the shape of a cube'

        Like a washing machine but bigger indeed.

        Launch mass 5,963 kg (13,146 lb)

        Dry mass 2,405 kg (5,302 lb)

        Good stuff with many countries contributing to the hardware, instruments too.

        1. Anonymous Coward
          Anonymous Coward

          Re: 'So it's in the shape of a cube'

          > Launch mass 5,963 kg (13,146 lb)


          > Dry mass 2,405 kg (5,302 lb)

          And the maximum wash load...?

  2. Wellyboot Silver badge

    Smaller Moons

    >>don't have any liquid water<< that we've detected, just like our Moon was 'dry' until long after we actually went there.

    1. diodesign (Written by Reg staff) Silver badge


      We thought that would be obvious - if we haven't detected any water then there isn't any to our mind - but we've made that clearer.

      You could add 'that we've detected' to anything. There's no more coffee left in the pot that we've detected. There's no patch yet from Microsoft that we've detected. And so on.


      1. TryingSomethingNew

        Re: Caveats

        Pah. That's not the same thing at all!

  3. lglethal Silver badge

    A thought experiment for the class

    I'm just wondering if for future missions To/Near Jupiter we can develop a power system that relies on that massive Jovian Magnetic Field? 20,000x what we see on earth must be able to be utilised somehow to produce Electricity, and thus compensate for the reduction in solar power.

    Diagrams on the back of a beer coaster only please...

    1. Charlie Clark Silver badge

      Re: A thought experiment for the class

      At the moment, it's too big to be useful. But basically anything ferromagnetic is a permanent generator, but also likely to be squashed to uselessness!

    2. cray74

      Re: A thought experiment for the class

      I'm just wondering if for future missions To/Near Jupiter we can develop a power system that relies on that massive Jovian Magnetic Field?

      Yes, they can, but you have to pay for that electrical energy from somewhere.

      Electromagnetic Tethers can offer propulsion or power generation depending on current direction and the external magnetic field.

      With electrical current flowing one way, perhaps from an RTG or solar panels, you can use an external magnetic field for propulsion and orbital reboost. Hubble uses a smaller, simpler Magnetotorquer system to aim itself and bleed down reaction wheels without rocket thrusters.

      In the other direction, you can convert a spacecraft's velocity and kinetic energy into electrical energy. Basically, you trade speed for juice. This can be useful if, say, you wanted to de-orbit an old satellite with a lightweight system (some electrical wire and aging solar panels), slightly slow a space probe without aerobraking or rocket fuel, and so on. But you are trading away kinetic energy to get that electricity.

      David Brin's 'Tank Farm Dynamo' is a short, 1983 hard science story looking at the utility of excess solar power and some long cables in orbit.

  4. werdsmith Silver badge

    I am going to follow this mission and CLIPPER very closely as long as I live long enough. Having done some research on Europa it's right up my street.

    1. Red Or Zed

      How did you get there??

      1. Sceptic Tank Silver badge

        Turn left at Mars

      2. werdsmith Silver badge

        How did you get there??

        You need a decent overcoat, a woolly hat and a thick pair of socks as it gets a but parky.

        1. Lars Silver badge


          I think one more question has to be asked.

          What did you research on Europa?

      3. Version 1.0 Silver badge

        The journey and the discovery of life was well documented years ago in the 1968 movie, "2001 a space odyssey"

        1. Yet Another Anonymous coward Silver badge

          It's fine, we are attempting no landings there

  5. graeme leggett Silver badge

    Gallileo reference

    I think Copernicus developed the notion that Earth etc circled the sun - writing "On the Revolutions of the Celestial Spheres"

    And Galileo followed up with "Dialogue Concerning the Two Chief World Systems" about 80 years later.

    (Though unsurprisingly a Greek had proposed heliocentric model much earlier)

    1. Charlie Clark Silver badge

      Re: Gallileo reference

      Church doctrine was really enforced mainly to show who's boss. Most of those who understood the matter had long accepted the heliocentric model, but the flat earth with Rome effectively at the centre was politically more acceptable as a bulwark against dangerous renaissance thinking.

      1. Anonymous Coward
        Anonymous Coward

        Re: Gallileo reference

        The Catholic church didn't believe in a flat earth. No one believed in a flat earth by that time in Europe.

        Galileo had advocated for heliocentric theory but been warned off going further in discussing it in 1616

        But Galileo's 1632 book comparing the two worldviews from a scientific angle, published with permission of the Church carried an inadvertent slur on the pope (Urban VIII, who had until then been a defender of Galileo),

        Accordingly Galileo had to made an example of. His works were banned and he was put under house arrest (though part of that seems to have been spent hosted by the Archbishop of Siena).

    2. diodesign (Written by Reg staff) Silver badge

      No problem

      Yeah, fair point, we've thrown some credit in for ol' Copie.


  6. Anonymous Coward
    Anonymous Coward

    Juice was Goosed

    High risk of lightning, so no launch today.

  7. WonkoTheSane

    Next launch attempt - 13:14 BST Friday April 14th.

  8. Potemkine! Silver badge

    Ganymede Elegy

    See you space cowboy.

  9. M.V. Lipvig Silver badge


    and I fully support this. Better to go there and look than try to look from Earth through a telescope.

    But, if Jupiter has a magnetic field 20,000 times stronger than Earth, and this craft will be whizzing along within it, seems like something could be made there. It might not make a lot of power, but then satellites are notoriously power efficient so wouldn't need much. Just a thought though, I have no idea if this would be possible.

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