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Comment by justinjlynn | Hacker News Reader

That is indeed awesome but I would argue that it also means we would need to undertake a much more thorough search to find out of mars is indeed a dead planet. Once we land a large concentration of biological matter there -- we won't have an opportunity to look again without dealing with massive potential for cross-planetary contamination.

Of course, it's a trade off and it's great news if we ever had to undertake a crash program to get at least a few humans and/or earth originated genetic material off planet with any hope of it surviving without extensive terraforming.

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If we want to search Mars for life before we contaminate it then we need to launch a crash program to do so now, because our window is swiftly expiring. Right now a small group with minimal resources (on the to build and launch stuff into space scale) could likely launch a cubesat with some sort of bacterial payload that would eventually get to Mars. Such a stunt is only going to get easier in the next few decades.

Explore Mars, in depth, ASAP, or someone will render the issue moot by starting their own terraforming project on the cheap. (Or the not so cheap. I don't believe Musk's colonization plans -if they ever come to pass- would be able to prevent contamination, no matter how hard they might try.)

>could likely launch a cubesat with some sort of bacterial payload that would eventually get to Mars

Curious how this might work, given the energy required not only to escape Earth's orbit, but to get into another one around Mars and crash into it. It's my understanding that cubesats don't have anything that could do any of that stuff, and a larger craft doing the heavy lifting would be way more complicated.

A solar sail and a bit of patience?

It would take some serious engineering chops to pull it off, but it's not totally implausible.

Sorry, I realize now that I may have sounded sarcastic. I really was curious, this makes sense. Thanks for responding.

They would have to get permission from the launching country, and that launch country would be obligated by the Outer Space Treaty to impose limits on contamination.

We have a big bucket of cash to do exactly that in the Mars2020 rover and other similar initiatives from other countries. It'll culminate with a cache of samples of martian soil returned to earth for experiments. I sincerely doubt anybody, regardless of money, could get a rover there sooner to find soil samples.

Under works: Cliff climbing robots to look at ice and water flows, quads to survey large areas up close and quickly, and man more.

It's progressing as fast as it can, but is often sidetracks by the whims of new administrations (moon! no, Mars! no, Moon!).

The evidence so far predicts that Mars is now sadly dead. The ratios of gases in its thin atmosphere are not consistent with a living planet (no oxygen, and the seasonal methane is probably geological). Ancient Martian life was probably identical to Earth's, due to similar conditions, chemistry and exchange of genetic information between the two planets (and Venus, in addition to life from other solar systems via comets). In the rocks we should find fossils eventually with our current rovers.

It might not be quite as bad as you think. I imagine Martian farmers would be doing something like hydroponics. The soil and water might come from mars but the actual plants grow in tiny, isolated compartments within buildings. I doubt the resource scarcity would allow for anything resembling a more traditional farm.

It's relatively easy to keep macroscopic plants from escaping, the real issue is the smaller stuff like bacteria, which will get everywhere no matter what kind of farm you're running.

Even there, though, they’re going to want to have air tight areas.

"Even there?" Forget the farm, this has nothing to do with farming per se. It doesn't matter if the crew does nothing but eat pre-sealed sterile goop.

The problem is that ensuring a sterile barrier so nothing gets out of your habitat-- especially when spacesuited living humans must pass through regularly -- is somewhere between incredibly expensive and just impossible.

So Earth bacteria will go out and contaminate Mars. sooner or later it would happen. We could still study the original Martian biome, if that exists.

The problem is, with Earth life present on Mars you can no longer be sure that the life you find there wasn't brought in by colonists.

Well, if they could be that alike, then it's not much worth studying anyway...

It would be worth studying - if they were much alike, the first obvious questions to answer would be "why" and "which came first".

Worth studying is an interesting term. I've got a bunch of things which are worth fixing, but none of them get prioritised. Would you say that it would be preferable to block the creation of a colony on the basis that it interferes research that might happen one day?

Personally I'd say no.

Didn't mean to imply it; I'm probably the last person on this site to argue against a colony on Mars. But it would be worth it if, during initial construction of the colony and preferably before sending men, we could send over some studies.

I think you've just made a compelling case for why we can make every species on earth extinct, apart from us and 'nothing of value would be lost'.

If that's sarcasm, I think you've exemplified the slippery slope fallacy and the straw-man argument.

Not at all. Your point was that if it is difficult to tell whether a particular organism was of terrestrial or martian origin, it must be so similar to Earth organisms as to be unworthy of study. If so, why bother studying more than one terrestrial organism?

That's such a simplistic view of life.

We would be able to identify an extraterrestrial cell as surely as if it was carrying flashing lights and screaming "I'm an alien". While all life is based on information, and information needs to be somehow encoded in a, let's call it, genetic code, would that code be DNA and RNA based? would in encode proteins, and if so, would the building blocks be the same 20 amino acids that we have an Earth. Would the genes be encoded using the same nucleotites, and would "letter" in the genetic code be encoded by 3 nucleotides? If so, would always the same 3 nucleotides encode the same aminoacid as on Earth? etc, etc.

There are so many places that life could be different, that the chance of mistaking Martian life for terrestrial life is vanishingly small.

What if it turns out that Earth's life and Martian life share the same origin?

Even if it turns out to be the case, there would be two forms of life separated by billions of years of evolution. Mistaking them would be much less likely than mistaking a cell from the wing of fruit fly from an onion peel cell: while on the outside they may look similar, the DNA of the fruit fly has about 170 million base pairs, while the DNA of the onion has 16 billion of them.

But would one kill off the other? They would probably still compete for scarce resources.

Exactly - like open source food computers! www.openagriculturesupply.com

is this a real concern? it should be relatively easy to distinguish life on earth from life on mars, should it exist. Especially considering it comes from a completely new path of evolution.

Furthermore, a mars station would allow science to be done directly on mars, rather than having payloads of material sent to and from earth.

You should read The Mars Trilogy by Kim Stanley Robinson. It's fiction, but it's one of the most well researched series of novels and is feels incredibly realistic, believable and it has really amazing characters/story to boot.

But this concern is expressed in that series, and it is a real one. The first people we send to Mars will not be visitors. They'll most likely be colonists. They will die there. Once they start to truly colonize (if they survive) we will loose the ability to determine if any microbes we find are Terran or Martian.

We still haven't interacted with all of the life on our own planet. There are things living in the dark places of the world that are difficult for us to reach.

Is it really necessary to preserve potential (but not confirmed) Martian life before establishing a beachhead?

That's my question as well. Judging by this thread, it appears we're not thinking hard enough about the unknowns, like what if Martian life is hostile to the microbes we depend on?

Are we welcome there? Will we have to engineer some kind of virus that's friendly to our life support that wipes out these unfriendly lifeforms?

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