Where have we looked, or are looking, for life?

[Jarvis323]

I am aware of some biological experiments on Martian soil that were conducted during the early days of space exploration (Viking). These tests were supposedly inconclusive, and we were not really looking in the most likely place anyways. Besides that, I have heard only about exploration missions to check for geological and atmospheric features that could suggest habitability, but no experiments aimed at detecting life itself. Additionally, I find that most people seem to think we have essentially been scouring Mars and elsewhere for life, but haven't found anything; sometimes this is in the form of an argument that life on Mars doesn't exist.

Given all of the extreme places we find life on Earth, I think that microbial life on Mars (and elsewhere outside Earth and within reach) is not too unlikely at all. And it's somewhat frustrating that we seem to not be actually looking.

Am I wrong? Have we tried, or will try to detect extraterrestrial life besides Viking? Why no plans to send submarines to any of the oceanic worlds in our solar system? Will we even bring the stuff to detect life if we ever do? Why no attempt to detect life in core samples on Mars? Am I the only one annoyed that we keep sending probes to the outer solar system only to take pictures? Is it really difficult to do more? How many years do you think it will be before we try to detect life again? Do you think private explorers will beat our space agencies to the punch?

 

[Borg]

Why no plans to send submarines to any of the oceanic worlds in our solar system?

Because it is difficult to get there in the first place and, once you get there, the water lies under tens of miles of ice. It is far more likely that the first probes of the moons that have water will explore the vents for signs of life or its byproducts. We are in the first stages of exploration where we are just finding out what the environment of these worlds is like.
BTW, seam is a noun. The correct usage is seem.

 

[Jarvis323]

Because it is difficult to get there in the first place and,

Are you sure this is a logical reason? Haven't we succeeded already when still in the infancy of space technology? Isn't the long wait and high cost only a bigger reason to try to do as much as you can when you actually make it there?

the water lies under tens of miles under an ice cap.

I guess this is true. I think Europa has about 10-16 mile thick ice. What are our limitations and challenges?

 

[Borg]

Again, we are in the first stage of exploring the solar system. We can't know to take a mini-sub and the tools to drill through miles of ice until we've been there to see what the environments are like. After that, there is a lot of hard work to analyze, prioritize and allocate. NASA has to then deal with re-prioritization of its budgets every time there is a new president. Then, after many years, they might be able to send a probe to check out an interesting location. Finally, sending the probe will be expensive and fraught with potential failures. It isn't a quick or easy process.

 

[Rubidium_71]

Contamination is also a consideration. For example, the wikipedia page on the Galileo Probe probe states:

Two years of Jupiter's intense radiation took its toll on the spacecraft 's systems, and its fuel supply was running low in the early 2000s. Galileo had not been sterilized prior to launch and could have carried bacteria from Earth. Therefore, a plan was formulated to send the probe directly into Jupiter, in an intentional crash to eliminate the possibility of any impact with Jupiter's moons and prevent a forward contamination.

I agree with Borg that study of the vents is a good place to start (Cassini already did some basic analysis of the material vented into space from Enceladus) but we should proceed with caution to avoid damaging any potential ecosystem.
I guess it's a matter of opinion what "stage" we're at in exploring the Solar System. If the proper funding was there we would be much further along than we are now, but our culture prefers to invest in disposable cell phones instead of space probes. However, we briefly put people on the moon and had great success with the Voyager probes back in the 1970's and 80's, I consider that pretty substantial progress.
I agree with Jarvis that not enough has been done. We could have pulled a polar ice core sample out of Mars and analyzed it years ago (like we analyze polar ice cores on Earth to study past conditions), but it hasn't been done. It likely never will be done.
While exploration of these moons is a laudable goal, it will take much more cash and innovation to see it though This is unlikely in the current political climate (as Borg pointed out). I would guess that many of us will not live long enough to find out if there is life on any of these moons, assuming the effort is ever made at all.

 

[russ_watters]

Are you sure this is a logical reason?

It is.

Haven't we succeeded already when still in the infancy of space technology?

Succeeded at what, exactly? I think you may have an overdeveloped sense of what we have done/can do.

Isn't the long wait and high cost only a bigger reason to try to do as much as you can when you actually make it there?

No. "try to do as much as you can" is expensive and limits your vision. One of the current mantras of the space program is smaller, lighter, faster, cheaper. In the long run it enables us (them) to do more because rather than have a very small number of very expensive missions, we have a large number of cheaper missions. Think of them as "screening studies": rather than explore one thing in depth and maybe find nothing, you explore a lot of things from a thin level and from what you learn target where the more detailed/expensive missions are warranted.

I think Europa has about 10-16 mile thick ice. What are our limitations and challenges?

We can't even drill that deep on Earth.

 

[russ_watters]

I would guess that many of us will not live long enough to find out if there is life on any of these moons, assuming the effort is ever made at all.

Perhaps not, but I'm after bigger fish. I suspect that scientists will determine to a high confidence that there is life elsewhere in the galaxy -- perhaps as soon as the next decade or two. Unfortunately when they do, the announcement will likely be boring and unconvincing for non-scientists.

 

[DrRck]

I am aware of some biological experiments on Martian soil that were conducted during the early days of space exploration (Viking). These tests were supposedly inconclusive, and we were not really looking in the most likely place anyways. Besides that, I have heard only about exploration missions to check for geological and atmospheric features that could suggest habitability, but no experiments aimed at detecting life itself. Additionally, I find that most people seem to think we have essentially been scouring Mars and elsewhere for life, but haven't found anything; sometimes this is in the form of an argument that life on Mars doesn't exist.

Given all of the extreme places we find life on Earth, I think that microbial life on Mars (and elsewhere outside Earth and within reach) is not too unlikely at all. And it's somewhat frustrating that we seem to not be actually looking.

Am I wrong? Have we tried, or will try to detect extraterrestrial life besides Viking? Why no plans to send submarines to any of the oceanic worlds in our solar system? Will we even bring the stuff to detect life if we ever do? Why no attempt to detect life in core samples on Mars? Am I the only one annoyed that we keep sending probes to the outer solar system only to take pictures? Is it really difficult to do more? How many years do you think it will be before we try to detect life again? Do you think private explorers will beat our space agencies to the punch?

As an evolutionary biologist, I agree to an extent that the results of the Viking labelled release experiments were a bit ambiguous, but I corresponded with Gilbert Levin in the mid-late 1980s, and I think that the biogenic signature in those results is stronger than many people suggest.

But searching for life elsewhere, in order to avoid this maddening ambiguity, really requires sophisticated instrumentation, and that in turn requires that resources be diverted from other, also valuable, scientific equipment that could be carried on a robotic probe. And to justify that kind of dedication of resources, you need a very strong reason to suspect that life is present wherever you're going, to begin with. That;s why so much of our Mars exploration has been dedicated to first detrermining if life might even be a possibility on Mars, before we try to go and look for it. The risk is what happened to the Beagle 2, which was specifically designed as a search for life on Mars, but ended up failing because its solar panels didn't completely unfold.

Sometimes, the U.S. in particular seems to make travel to other bodies in the solar system look easy, but it's not. And in the case of icy bodies like Enceladus or Europa, you need extensive prior reconaissance to even determione a landing site, and after that, the technology to gain access to that sub-ice ocean.

 

[1oldman2]

Enceladus appears to be the new favorite, beating out even Europa as the most likely candidate.
http://www.sciencemag.org/news/2017...ly_2017-04-14&et_rid=281473709&et_cid=1274349

http://science.sciencemag.org/content/356/6334/155

 

[Rubidium_71]

Perhaps not, but I'm after bigger fish. I suspect that scientists will determine to a high confidence that there is life elsewhere in the galaxy -- perhaps as soon as the next decade or two.

I hope you're right, there are a lot of people working on it at this point.