Stranger than fiction: The search for habitable exomoons


25 Responses to “Stranger than fiction: The search for habitable exomoons”

  1. Theophylact says:

    Other early fictional inhabited gas-giant moons include Titan (in Heinlein’s The Puppet Masters and Vonnegut’s The Sirens of Titan), Triton (in Delany’s novel of the same name), Jinx (in Niven’s Known Space universe) and even the Earth (in Niven’s A World Out of Time, it’s been moved into orbit around Jupiter when the Sun heats up enough to make its present neighborhood uninhabitable).

  2. DarthVain says:

    Life maybe, but likely primitive, or not as we know it.

    The obvious problem is large gas giants so far as I know typically exist outside the sweet spot of “habitable” zone. Thus any moon of a gas giant will likely be far enough away from the sun as to make it pretty damn cold. You would have better luck maybe finding ice microbes than any forests, unless they are composed of very different materials and processes that life as we know it exists. There is some thought that some of these moons, would be subject to large amounts of fluctuating gravity from orbiting such a massive object, and as such the constant squeezing and crushing could mean that they stay volcanic longer, and that this heat and gas productions might make life more habitable. Of course that is a pretty harsh environment by itself, let alone having to deal with the gravity itself.

    So I would say, if forest moon’s like endor’s does exist I would suggest they are by far rarer than even ideal Earth type environments. While its wonderful to speculate we can only really extrapolate from what our current solar systems is composed of. Basically assume that our solar system is typical rather than atypical and go with that.

    • Lee Billings says:

      Hi Darth,

      Good news — we actually are talking about gas giants in the habitable zone. There were several such worlds known prior to Kepler’s latest data release, though they don’t transit, so they aren’t suitable for the observations Kipping discusses. But now Kepler is finding these things by the dozen in the habitable zones of stars. And many of the planets it is finding — notably the “super-Earths” and “hot Neptunes” — have no analogs in our own solar system. So it may well be that our solar system is atypical in at least that way.

  3. Anonymous says:

    Does anyone know of a sky sim for exomoons?

    The closest I’ve found is the recent what would other bodies look like in the place of our moon. It’s easy enough to imagine you’re on Europa with Jupiter filling the sky.

    But what about the day/twilight/dark/night cycles on a planet orbiting a planet orbiting a star? Assuming you’re not locked into a tidal orbit what type of sky would you experience through a rotational period around the planet?

    • Kimmo says:

      Does anyone know of a sky sim for exomoons?

      The closest I’ve found is the recent what would other bodies look like in the place of our moon. It’s easy enough to imagine you’re on Europa with Jupiter filling the sky.

      But what about the day/twilight/dark/night cycles on a planet orbiting a planet orbiting a star? Assuming you’re not locked into a tidal orbit what type of sky would you experience through a rotational period around the planet?

      Celestia will do the job.

      It’s relatively straightforward to plug in whatever numbers you want, too.

  4. DarthVain says:

    of course using power armor and blasters and getting owned by care bears with sticks and rocks doesn’t sound very competent either.

    I always thought Ben was joking when he said “Look at this accuracy, these can only be done by imperial storm troopers.”

    In that it must have been like wild missing shots everywhere…

  5. Xeno says:

    I don’t know why anyone isn’t thinking about the social aspects of this but society would change dramatically (much less the effects it would have on our psyches) to live a somplace where the ENTIRE PLANET was is pitch blackness!

    If the had a 24 hr rotation not too big of a deal (although hourly blackouts would take getting used to with the moons rotation) but if it was the size of jupiter, you would have the entire planet blacked out by the planet for a period of a couples days. This means no solar power and the planet getting colder and colder with each day (as we rely heavily on the sun for our weather).

    Movies make it seem simple and fun but it’s actually a far more complex thing when you take into account how a large astronomical body can have an effect on a smaller one. Moons would be hard to inhabit and it would be a tough life.

  6. Anonymous says:

    Interesting post, but it wasn’t Ewoks and Endor that started the idea of habitable moons . . . try “Farmer in the Sky” by Heinlein, a nice 1950′s rendition of terraforming and colonising Ganymede.

  7. Sapa says:

    Looking for clues in the movement of planetary bodies is all well and good but personally I am not satisfied with present explanations for the precession of the equinoxes here on Earth. If our present explanations are wrong and we are in fact influenced by another large body then isn’t it possible that wobbles in the movement of other bodies may be caused by factors that are not taken into consideration?

  8. quitterjunior says:

    Dear BoingBoing:
    You get me laid. And I live in Texas…

  9. jon_anon says:

    Lee, thanks for the confirmation. It is simultaneously frustrating to think there might be a system very near by that this method would miss because of an orthogonal viewing angle, and uplifting to think that all these planetary discoveries (and the ones to come) are from the very slim proportion of systems whose orbital plane is oriented to match our line of sight.

    I understand that a view from above or below the orbital plane allows us to see the ‘wobble’ better from the pull of nearby planets–but unless I’m mistaken this method will not allow us to detect earth-sized wobbles at earth-like orbits for the foreseeable future, with optical resolution being what it is, right?

    • Lee Billings says:

      Actually, Jon, it’s relatively straightforward to make those astrometric observations using a custom-built interferometric space telescope. NASA poured hundreds of millions of dollars into developing the technology to do this, and had planned to launch a space telescope called the Space Interferometry Mission (SIM, later downgraded to SIMLite) to survey nearby stars for planets.

      But despite all that sunk cost, SIM failed to make the cut in the recent Decadal Survey, a high-level report from leaders in the US astronomy/astrophysics community that is meant to prioritize missions and lay out the near future of the field. That left a pretty important capability gap that planet-hunters are scrambling to fill. I wrote about this in a lot more detail in this recent Nature News feature article:

      Check it out!

  10. RedShirt77 says:

    If titan has no life, I think we should take some there.

    I mean and leave some sort of marker that lets the glow in the dark fish people that eventually evolve there that they were planted there by Aliens.

    There version of the History Channel could run shows about us, like ours does about imaginary aliens.

    • Maggie Koerth-Baker says:

      Sooooo … NASA should engage in interplanetary, long-term trolling?

      • RedShirt77 says:

        Oh, that’s a good idea too. Leave a DVD of Carrot Top’s “Chairman of the Board” movie Sealed in resin so 100 million years down the line when they decode it, they will be completely fucked.

  11. Brainspore says:

    Such a discovery would raise so many questions. For example, would those aliens refer to exposed-ass-based taunts as “planeting?”

  12. ColHapablap says:

    Yavin IV, the Rebel base in the original Star Wars, was also a moon orbiting a gas giant (Yavin). I always wondered why they didn’t just blow up the main planet with the Death Star, but instead went all the way around it to take out the one moon.

    Yeah, now who’s cool.

    • Anonymous says:

      Total SW tangent (which is embarrassing because I am deeply interested in the primary topic, in fact it’s why I clicked), but my sense is the Death Star could only blow up planets/moons of a certain size. Yavin, the main planet, was just too big.

      This is merely a hunch based on the scenes we did see in Star Wars and not on any scientific data; just observable. Yavin seemed *much* bigger than Alderaan or Yavin IV; obviously, since it filled the screen and we never got to see the whole thing.

      • DarthVain says:

        While not presuming to know the technology behind the DeathStar, I know having discussed before that the empire was more about fear than anything else. Sure blowing up a planet is pretty cool, but now you don’t have a planet. All you really need to do is wipe out the population, which presumably would be a heck of a lot easier than blowing up a whole planet.

        So while even if one planet is too big to blow up, surely it is at least enough to seriously f-up the population there. Unless it is an all or nothing weapon, it either blows up an entire planet or doesn’t even nudge a kittens whisker… which I would say is a bit of a flaw in a galactic super weapon… just sayin’…

  13. jon_anon says:

    Hey Lee, thanks for these posts. Can Kepler and other transit-detecting approaches only detect planets if a system is edge-on to us? What percentage of systems are likely to present edge-on within the tolerance of this approach? If anyone was looking at our solar system from above or beyond its plane, they wouldn’t detect anything, right?

    I guess if I’ve understood this right it means that the results are even more positive, if they’ve managed to find so many planets in the small percentage of systems that just happen to be edge-on to us.

    • Lee Billings says:

      Hi Jon, thanks for reading them!

      A planetary system doesn’t have to be exactly edge-on to us for us to detect some transits, but the window of orbital inclination deviations from edge-on is pretty narrow, within something like 5-10%.

      Observers examining our solar system at an orthogonal angle to our general orbital plane wouldn’t be able to see transits, no, but they would have the opportunity to see almost the full astrometric reflex motion of our Sun as its planets tugged it around in their orbits.

      You have indeed understood the gist of things correctly: Only a fleeting fraction of planetary systems display transits for our line of sight. So this is just the tip of the iceberg, really. Planets are everywhere!

  14. karl_jones says:

    Never mind the exomoons — Jack Handey is worried about the Gas Giants:

    Whether they ever find life there or not, I think Jupiter should be considered an enemy planet.

    – Jack Handey

  15. Sapa says:

    I hope our trusted scientists don’t leave any more signposts pointing to us like Carl Sagan did in the 70′s. They could be taken as invitations to partake in interstellar refreshment by aliens akin to the ones that Sigourny Weaver spent so much time keeping away from us in the Alien movies. Hopefully at least it would deter the builders of interstellar bypasses to make a detour around our little backwater.
    I still think we first ought to look more seriously at contacts that have already taken place here at home.

  16. Kimmo says:

    Some Celestia screencaps: 1 2 3 4 5

    The last one is a view from a moon… and of course, you can speed up time as much as you want.

  17. angusm says:

    I’d be curious to know what the effect of the radiation belts surrounding a giant planet would be an accompanying habitable moon. Are such belts typical to all Jovians and, if so, what proportion of its possible moons would be subject to radiation at levels harmful to life?

    A giant planet might also be an uncomfortable neighbor in that it would draw any stray debris towards it, and its moons would probably stop some of the inbound matter (the moons of our own giants are heavily pitted with meteor impacts). A rain of rock and ice might be either a kickstarter or a killer as far as struggling early life (and even advanced life) was concerned.

    It would be interesting to speculate on the effects on complex life (or culture) of other factors associated with a giant neighbor. If the moon orbited the giant in the plane of the ecliptic (which seems plausible), you’d probably get frequent eclipses, plus days when the giant was reflecting an extra dose of sunlight onto the ‘night side’ of the planet. And what if the moon was tidally locked to its giant parent? That would make things interesting.

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