# Life Elsewhere in our Solar System –Surprised or Not? **URL:** \ **Category:** Great Debates\ **Created:** [March 10, 2006, 3:18pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831 "2006-03-10T15:18:09Z")\ **Posts on this page:** 18\ **Page:** 2
**Author:** ![Rune](https://avatars.discourse-cdn.com/v4/letter/r/e68b1a/32.png) [@Rune](https://boards.straightdope.com/u/Rune)\ **Post date:** [March 11, 2006, 9:41pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/21 "2006-03-11T21:41:44Z")
I think most scientists agree that it is very unlikely that life occurred twice. Which means all Eart life is related. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [March 12, 2006, 4:49am UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/22 "2006-03-12T04:49:39Z")
> [@Guinastasia](#): > > In our solar system? Yes-I don’t think any of the other planets or moons are capable of supporting life. > > In our _galaxy_? Hell no! Don’t be too quick with that. We’ve learned a lot about how resilient life is in the last couple of decades. There was a time when biologists were pretty sure that life needed water that was slightly above the freezing point, and that it couldn’t exist in harsh environments. Since then, we’ve been finding life on earth in the harshest places imaginable, such as 400 degree thermal vents on the ocean floor spewing toxic chemicals into the water. The life there isn’t even part of the photosynthesis chain - it gets its energy from the heat and chemicals coming out of those vents. So when you have worlds like Enceladus or Europa, which have liquid water and have probably had it for a long, long time, you have to wonder if life would be there. Both planets are being heated from within, so there have to be regions just like those thermal vents on Earth. So they don’t need sunlight to exist, and that’s about the only thing they are missing. I don’t think anyone is expecting oceans teeming with strange fish or anything, but I don’t think many biologists today would be surpirsed if we found microorganisms or other primitive life in those oceans. Enceladus made significant news this week: [Alien Water Everywhere](http://www.msnbc.msn.com/id/3217961/) Scientists are calling ths the most important discovery in space in 25 years. We’ve found a moon that is literally spraying liquid water into space, with an ocean maybe only a few meters below the surface, instead of hundreds of kilometers. We could probably design a probe to get through that today and have it swimming in an extra-terrestrial ocean within a decade. Or we could fly a material-catching probe like the Stardust probe right through one of those clouds of mist and collect material for study at home to see if there’s alien bacteria in it. ---
**Author:** ![Guinastasia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guinastasia/32/5751_2.png) [@Guinastasia](https://boards.straightdope.com/u/Guinastasia)\ **Post date:** [March 12, 2006, 4:54am UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/23 "2006-03-12T04:54:27Z")
Fair enough, **Sam**. What about intelligent life, though? ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [March 12, 2006, 5:00am UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/24 "2006-03-12T05:00:11Z")
> [@](#): > > instead of hundreds of kilometers Oops. THat shoulnd’t be hundreds. It should be kilometers. Europa’s ice shell is 3-4 kilometers thick. But that’s still 3-4 kilometers we don’t know how to get through. Enceladus might have spots where the water is virtually on the surface, with maybe only a few meters of ice over it. We could melt our way through that with a nuclear power source. I can imagine a robot that would set up an antenna on the surface, then melt it’s way through the ice trailing an umbilical behind it for communication. I could even see one attaching an anchor to the surface then melting its way into the ocean, then swimming around on the tether under there taking measurements, then melting its way back to the surface if it had to. ---
**Author:** ![ivylass](https://avatars.discourse-cdn.com/v4/letter/i/9de053/32.png) [@ivylass](https://boards.straightdope.com/u/ivylass)\ **Post date:** [March 12, 2006, 8:17pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/25 "2006-03-12T20:17:23Z")
> [@cmyk](#): > > I strongly believe that life exists elsewhere in our universe… even within our galaxy. But, even at this cursory, overall glance we’ve had at our own solar system, I feel we would have seen SOME evidence already that there my exist some life on another nearby world. If microbial evolution took hold on a moon like Enceladus, even if it had half the time earth did for developing organisms, wouldn’t it already be smothered in life-forms? If our planet is any clue… Once life takes hold, it practically takes over. We’re not even done exploring the ocean floor, we’ve barely scratched the surface in exploring our solar system…what, a couple of fly-bys of Jupiter and Saturn? Some robots trundling along the surface of Mars? Just because we haven’t found evidence of life doesn’t mean it isn’t there. Who knows what’s swimming in the goop that is Jupiter’s surface? Maybe it’s my geeky Star Trekedness talking, but I cannot believe life is an anomaly and not the norm. ---
**Author:** ![Revtim](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/revtim/32/1042_2.png) [@Revtim](https://boards.straightdope.com/u/Revtim)\ **Post date:** [March 12, 2006, 8:30pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/26 "2006-03-12T20:30:03Z")
I think at least ET microbial life is likely in our solar system, mainly because there’s a regular exchange of material between the planets. That Martian meteorite may or may not have evidence of life in it, but it showed pretty conclusively that _some_ material travels between the worlds. Seems likely some germs will take the trip some time, and not all die on the way or on landing. That, plus the possibility that it came about independently might make it a pretty safe bet. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [March 12, 2006, 9:44pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/27 "2006-03-12T21:44:41Z")
> [@ivylass](#): > > Just because we haven’t found evidence of life doesn’t mean it isn’t there. Who knows what’s swimming in the goop that is Jupiter’s surface? Maybe it’s my geeky Star Trekedness talking, but I cannot believe life is an anomaly and not the norm. AFAIK, only two important SF writers have done any recent exploration of the theme of ET life within the Solar System: The late (as of 2002) Robert L. Forward. See his novels, _Saturn Rukh_ and _Camelot 30K_ (the latter set on Pluto). Ben Bova, in his “Grand Tour” series of within-the-Solar-System novels, has treated ET life as an incidental theme, with one exception: _Jupiter,_ which is entirely about the search for Jovian life (and how human religious conservatives react to it). ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [March 13, 2006, 1:07pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/28 "2006-03-13T13:07:53Z")
> [@ivylass](#): > > We’re not even done exploring the ocean floor, we’ve barely scratched the surface in exploring our solar system…what, a couple of fly-bys of Jupiter and Saturn? Some robots trundling along the surface of Mars? > > Just because we haven’t found evidence of life doesn’t mean it isn’t there. Who knows what’s swimming in the goop that is Jupiter’s surface? Maybe it’s my geeky Star Trekedness talking, but I cannot believe life is an anomaly and not the norm. That’s true, and it doesn’t get mentioned nearly often enough. For instance, there has been only one manned expedition to the deepest part of the ocean, it was 46 years ago, and it lasted less than half an hour. 😛 ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [March 13, 2006, 7:12pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/29 "2006-03-13T19:12:42Z")
> [@ivylass](#): > > We’re not even done exploring the ocean floor, we’ve barely scratched the surface in exploring our solar system…what, a couple of fly-bys of Jupiter and Saturn? Some robots trundling along the surface of Mars? > > Just because we haven’t found evidence of life doesn’t mean it isn’t there. Who knows what’s swimming in the goop that is Jupiter’s surface? Maybe it’s my geeky Star Trekedness talking, but I cannot believe life is an anomaly and not the norm. I’m certainly not gonna argue with you on that point. We haven’t even scratched the surface of why lies in the depths of our very own solar system. It excites me to think what might be lying beneath some other world this whole time, unbeknownst to us, practically in our cosmic backyard. But I look at a world like our earth, and see life busting at the seams. If another planet (or moon) has the merest speck of life, I would expect it to adapt just as efficiently as it has on earth, and take over… exploiting every nook and cranny possible for a new habitat. We haven’t seen that on any of the terrestrial planets. Should we take this as a sign that maybe it’s more likely that there is nothing there? ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [March 13, 2006, 7:19pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/30 "2006-03-13T19:19:04Z")
Also think about this. If we landed a modern-day probe on our own planet (not unlike the Mars rovers), with just 1% of the unintelligent life that exists now, don’t you think we would have discovered it almost immediately? ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [March 13, 2006, 8:02pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/31 "2006-03-13T20:02:11Z")
The Enceladus eruption should be able to tell us a lot. If there are bacteria in the geyser water, shouldn’t we be able to detect them spectroscopically? I believe Freeman Dyson suggested dropping a probe on Europa that would be just a large mass. When it hit the ice it would create a spray of vaporized water, and we could analyze the composition of the spray to tell if there were any energetically unlikely chemicals that were probably produced by life forms. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [March 14, 2006, 12:22am UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/32 "2006-03-14T00:22:23Z")
> [@Lemur866](#): > > The Enceladus eruption should be able to tell us a lot. If there are bacteria in the geyser water, shouldn’t we be able to detect them spectroscopically? I believe Freeman Dyson suggested dropping a probe on Europa that would be just a large mass. When it hit the ice it would create a spray of vaporized water, and we could analyze the composition of the spray to tell if there were any energetically unlikely chemicals that were probably produced by life forms. Is the Cassini probe equipped to do that? ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [March 14, 2006, 7:20pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/33 "2006-03-14T19:20:58Z")
No, Cassini had a lander for Titan. I don’t know if anyone suspected Enceladus had liquid water like Europa. I know this eruption is the first I’d heard of it. If we want to drop an impacter on Europa or Enceladus we’d have to propose a whole new mission. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [March 14, 2006, 8:55pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/34 "2006-03-14T20:55:54Z")
> [@Guinastasia](#): > > Fair enough, Sam. What about intelligent life, though? In our solar system? Not a chance. I would be shocked if there is even complex life in our neck of the woods. However, the question was simply ‘life’…and I think there is a pretty good shot at that in the solar system. In the wider galaxy I’d have to say that the odds are good that there is complex and intelligent life out there somewhere. But…what are the odds we’ll ever find it? Certainly not good when we don’t seem interested in pushing our space program… -XT ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [March 14, 2006, 9:30pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/35 "2006-03-14T21:30:57Z")
Let’s say we did find life, in whatever complexity, on another world in our S.S. And we determined that it has DNA, would this be conclusive evidence that the lifeform originated from earth somehow? If not, how could we determine if it began on its own, or came from earth, eons ago? ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [March 14, 2006, 9:40pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/36 "2006-03-14T21:40:01Z")
I would guess that DNA itself wouldn’t prove that earth life and the new life had a common ancestor. It might be that DNA is an “obvious” solution that any form of life might have. But the triplet codons that DNA uses to code for amino acids are pretty much arbitrary as far as I know. And all life on earth uses the same triplet codons for the same amino acids, which is pretty good evidence that all life on earth shares a common ancestor. If the alien life used the same codons to code for the same amino acids that would be a smoking gun that it shares a common ancestor with earth life. I think we could use lots of other biochemical pathways to prove how related the alien life is to earth life, since some things might be neccesary for all we know, but others seem completely arbitrary. And if we determine that earth life and the alien life were related, it wouldn’t prove that alien life came from earth, or that earth life came from the other planet/moon, both could have come from a third source. ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [March 14, 2006, 9:47pm UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/37 "2006-03-14T21:47:00Z")
To expand on that a bit. If we knew the alien life and earth life were related, tne way we could prove the source of the origin is if all alien life or all earth life is more closely related to only one branch of life on the other world than it is to any other branch. So if the alien life were all one particular strain of bacteria, while we have a larger diversity of bacteria on Earth, that would be good evidence that the alien bacteria came from earth. Likewise, if all earth life fits into one clade of alien life then that’s pretty good evidence that earth life didn’t originate on earth. ---
**Author:** ![Measure\_for\_Measure](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/measure_for_measure/32/557_2.png) [@Measure\_for\_Measure](https://boards.straightdope.com/u/Measure_for_Measure)\ **Post date:** [March 15, 2006, 8:08am UTC](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831/38 "2006-03-15T08:08:26Z")
> [@xtisme](#): > > I would be shocked if there is even complex life in our neck of the woods. Multicellular life wouldn’t surprise me. [The thermal vent ecosystem](http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/oceanography_recently_revealed1.html) supports [clams](http://www.resa.net/nasa/ocean_hydrothermal.htm) and tube worms. Octopuses have been spotted nearby, though they presumably didn’t evolve in such an environment. [Previous page](https://boards.straightdope.com/t/life-elsewhere-in-our-solar-system-surprised-or-not/347831.md?page=1)