
I’m Convinced We Found Evidence of Life on Mars in the 1970s - simulate
https://blogs.scientificamerican.com/observations/im-convinced-we-found-evidence-of-life-on-mars-in-the-1970s/
======
alister
What, no mention of ALH84001? I was mesmerized by the live TV press conference
by a large group of NASA scientists back in 1996 of evidence of life on Mars
from the analysis of a meteorite:

"Scientists headed by David McKay of the JohnsonSpaceCenter in Houston found
that the rock, called ALH84001, had a peculiar chemical makeup. It contained a
combination of minerals and carbon compounds that on Earth are created by
microbes. It also had crystals of magnetic iron oxide, called magnetite, which
some bacteria produce. Moreover, McKay presented to the crowd an electron
microscope view of the rock showing chains of globules that bore a striking
resemblance to chains that some bacteria form on Earth. “We believe that these
are indeed microfossils from Mars”"[1]

I was disappointed that the story fizzled out. One microbiologist concluded
that bacteria from Earth had "contaminated the Mars meteorite. Other
scientists pointed out that nonliving processes on Mars also could have
created the globules and magnetite clumps." But I don't think life is ruled
out. This meteorite is hanging in as a "just maybe" like the Viking mission
discovery.

[1] [https://www.smithsonianmag.com/science-nature/life-on-
mars-7...](https://www.smithsonianmag.com/science-nature/life-on-
mars-78138144/)

~~~
ianai
I fear that the “it’s never aliens” credo was taken to the pathological case.
Nothing can be life so why look for it? Nothing can be life, so any really
complicated scenario not involving life must be true, always.

~~~
asdff
But they are looking for it. Science demands evidence for your claims. If x
could be due to a, but also b, c, d, maybe e, you can't say x = a until you've
proved that x ≠ b, c, d, e.

~~~
rzzzt
"However improbable", Sherlock Holmes is often brought up in cases like
this...

~~~
cgriswald
That quote always rubs me the wrong way. To reach certainty through deduction
you need a closed domain. Assume Holmes is 100% correct about the information
he has, and he has three suspects, two of whom he ruled out. Does that mean
the third did the deed? No. There may be information Holmes does not have and
there is really no way for Holmes to know he does not have that information.

~~~
rzzzt
Holmes does appear to be operating under the closed-world assumption:
[https://en.wikipedia.org/wiki/Closed-
world_assumption](https://en.wikipedia.org/wiki/Closed-world_assumption)

------
eindiran
It looks like a lot of people think the presence of the oxidizer perchlorate
is the cause of the false positive, but there isn't consensus yet.

```

On August 2008, the Phoenix lander detected perchlorate, a strong oxidizer
when heated above 200 °C. This was initially thought to be the cause of a
false positive LR result. However, results of experiments published in
December 2010 propose that organic compounds "could have been present" in the
soil analyzed by both Viking 1 and 2, since NASA's Phoenix lander in 2008
detected perchlorate, which can break down organic compounds. The study's
authors found that perchlorate can destroy organics when heated and produce
chloromethane and dichloromethane as byproduct, the identical chlorine
compounds discovered by both Viking landers when they performed the same tests
on Mars. Because perchlorate would have broken down any Martian organics, the
question of whether or not Viking found organic compounds is still wide open,
as alternative chemical and biological interpretations are possible.

...

In a paper published in December 2010, the scientists suggest that if organics
were present, they would not have been detected because when the soil is
heated to check for organics, perchlorate destroys them rapidly producing
chloromethane and dichloromethane, which is what the Viking landers found.
This team also notes that this is not a proof of life but it could make a
difference in how scientists look for organic biosignatures in the future.

```[0]

It's funny that perchlorate is likely what confounded the LR experiment, as
the discovery of perchlorate in the soil made a lot of folks less optimistic
about life being able to survive on the Martian surface.[1]

[0]
[https://en.wikipedia.org/wiki/Viking_lander_biological_exper...](https://en.wikipedia.org/wiki/Viking_lander_biological_experiments)

[1]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5500590/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5500590/)

~~~
labster
Yep, definitely ironic that an oxidant like perchlorate _reduced_ the chance
of finding life.

You’ve been a great audience, I’ll be here for the next 7 sols!

------
amingilani
> Inexplicably, over the 43 years since Viking, none of NASA’s subsequent Mars
> landers has carried a life detection instrument to follow up on these
> exciting results

I'm very surprised by that.

Especially since, as the article says, "NASA maintains the search for alien
life among its highest priorities".

I thought that would obviously translate to sending life-detection instruments
to B̶a̶r̶s̶o̶o̶m̶ Mars.

~~~
noetic_techy
This fact often catches people by surprise when I tell them also. The more
conspiratorial theory is that JPL prefers not to include life detection
equipment because it would mean the end of robotic missions and more of an
emphasis to get humans there to do real biology, which is more the domain of
Houston Mission Control. Follow the money...

~~~
arcticbull
Cmon folks, let’s be realistic. If someone at NASA had indeed reason to
believe life exist(s/ed) on Mars it would 200% have leaked by now. No funding
discussion would inhibit someone from leaking this information. It’s the
biggest discovery in human history and you think someone’s sitting on it for
funding reasons?! Especially since the immediate reaction would be to pour
billions into them following up?

A big discovery has a high burden of proof and that’s basically where we’re
at. There’s definitely reason not to rule it out but I can’t believe
conclusive evidence is being sat on by _all of NASA_ for _funding reasons_.

Let’s speculate for a sec. Tardigrades can survive space. Things have been
hitting us knocking earth stuff into space for billions of years. Some of that
stuff probably made it to Mars and back in the day it was pretty liveable.
It’s not far fetched. None of that negates the above.

~~~
aflag
I don't think that microscopical life in Mars is the biggest discovery in
human history. It's more like an interesting trivia. But it doesn't change
people's lives any more than the discovery of water on Mars.

~~~
slfnflctd
It may not change people's lives directly (unless you're an astrobiologist),
but it would absolutely change our lives indirectly-- the effects on the
future of space exploration and the ongoing human conversation would be
dramatic. Ultimately no one's mind is likely to be changed about much of
import - such as religious beliefs - but at the very least it will mean we
approach Mars missions differently.

~~~
aflag
It'd surely have impact in the related fields. However, I'd save the "biggest
discovery" title to findings that debunk and completely change our
assumptions, rather than more evidence for assumptions we already hold.
Perhaps, having another life origin to study will lead us to new
understandings. But the mere discovery of alien life is not that disruptive.

Given all theories and evidences we've observed thus far it's expected that we
are not the only living things in the universe. Except for some fringe
theorists, everyone expects life to exist in other places besides Earth.
Finding out that life exists elsewhere in the solar system would just be more
evidence for what we already belive to be true. So, not really huge news in
itself.

~~~
slfnflctd
Solid point, if you're academically inclined. For the majority of the world's
population, though, it's hard not to think "ALIEN LIFE CONFIRMED" headlines in
every major news outlet might lead to some other shifts in public opinion.

------
avian
> Ghost-like moving lights, resembling will-O’-the-wisps on Earth that are
> formed by spontaneous ignition of methane, have been video-recorded on the
> Martian surface;

I was surprised by this statement. I thought atmosphere on Mars is too thin to
support any kind of combustion.

After some searching the closest thing I found was a bunch of popular science
articles seeing aliens in white pixels on images from Curiosity [1]. It seems
all very much like people trying to make a thing out of image artifacts.
NASA's much more reasonable explanation is stray reflections in the optics or
cosmic particles striking the detector.

[1] [https://www.cnet.com/news/nasa-mars-curiosity-rover-saw-a-
we...](https://www.cnet.com/news/nasa-mars-curiosity-rover-saw-a-weird-light-
but-dont-freak-out/)

------
api
I get the feeling that contrary to rhetoric the search for life on Mars or
anywhere else is almost an anti-priority. Not much designed to look for life
has been sent since Viking in spite of direct observation of water ice, brine,
and other features suggesting ideal landing sites for such experiments.

If perclorates were the cause of the Viking positive as many suggest, why not
send a new experiment designed to rule that in or out? Why not send a whole
lot more chemical tests for biology, or a microscope for that matter?

I suspect there is strong concern about the social effects of the revelation
of any extraterrestrial life, even microbes. From what I see of the mass
psychosis that is most of current political discourse this concern might not
be unfounded.

~~~
newdayrising
I think it's the opposite. There are scientists who are obsessed with finding
extraterrestrial life because of their philosophical views regarding man's
place in the universe. The fact that our universe seems primed for life has
bothered so many gung ho atheistic scientists that they've conjured all sorts
of semi-pseudoscientific multiverse theories (Sean Carroll). That's one part
of it. The second part it's reducing abiogenesis to a simple process that just
"takes time" and is almost _inevitable._ The goal is to try to shove bare
faced facts into a dusty drawer while you trot out the latest sensational
theory. This is why there's been constant attacks on the Big Bang theory even
though it's one of the triumphs of modern cosmological science. It all becomes
so easy to justify when you define science as "what atheists believe."

~~~
smohare
Methodological naturalism as applied to the scientific Certainly has no
dependence on atheism.

Who categorizes science as an intrinsically atheistic endeavor other than
religious apologists?

~~~
api
The perception that all scientists are atheists comes from a small number of
loud dogmatists. This is exactly like the perception that all Christians are
literalist fundamentalists or hold right wing political beliefs.

~~~
usedToLife
All scientists are not atheists, just the smart ones. Depends on your
interpretation of the word though. I don't consider atheism to be a complete
abscence of philosophical pondering. I believe we haven't explored emergent
consciousness enough and that makes it a mystery. But a scientist believing in
a God from an ancient textbook is a red flag for me

~~~
bluquark
Only 7% of Nobel Prize winners are "smart"?
[https://commons.m.wikimedia.org/wiki/File:Religion_of_Nobel_...](https://commons.m.wikimedia.org/wiki/File:Religion_of_Nobel_Prize_winners.png)

------
psaux
I often wonder why these are always auxiliary conversations. Ever since I was
young, like most kids (I have 4), I also had this deep yearning for knowledge
on life external to earth. Wonder why this never has gone mainstream.

~~~
AndrewKemendo
Let's assume for a moment that we did find something resembling simple organic
life on Mars and confirmed that earth isn't the only life bearing planet. What
functionally changes for our existential understanding of the universe? I'd
argue little to nothing. We'd learn a bit more about organic life, but no
fundamental philosophical or existential questions would be resolved. Life has
been confirmed to be able to thrive in many more extreme places here on earth
than anywhere observed on Mars. There wouldn't be any firm resolution on the
question of whether humans are the only intelligent species in the universe.

I think that would be a different answer if we found inorganic life, as that
would blow up the concept of organic life as singular in "life" bearing
capability. I doubt we would recognize inorganic life as "life" in that case
however, as humanity has a poor working definition of "life."

Absent a recognizably intelligent form of life found off planet, I doubt much
would change (practically or existentially) for us here on earth.

~~~
dleslie
> What functionally changes for our existential understanding of the universe?

The anthropic principal becomes less compelling; to say nothing of the
religious implications.

~~~
jacquesm
Religion will have absolutely no problem to adapt to new information and
incorporate it as though it had always been there. This has happened time and
again in the past to the point where the religions of old would have been in
direct contradiction with even the most basic scientific knowledge if they
didn't adapt. The funny thing is that the so-called holy books are full of
stuff that no sane human would believe in. That doesn't stop a lot of people
from doing just that when those books are creatively re-interpreted by
intermediaries.

Religion will last for a very long time into the future, forget about major
lasting change on that front other than some rearguard action to ensure
survival.

~~~
dleslie
I did not intend to state the implications are the end of religion; simply
that many faithful will alter their faith, in no small manner.

~~~
jacquesm
I highly doubt that. If the genetics, the silicon revolution, access to space
imagery, quality education, the internet and science in general did not alter
faith in a drastic way I don't think 'life on Mars' is going to do anything
either unless it comes in the form of little green creatures.

~~~
dleslie
Curious that you don't recognize a significant shift in religious thought in
the last century.

~~~
jacquesm
What shift would that be?

Until the 1970's or so it was getting better, since then it's gotten worse if
anything.

On the Christian side we have whole continents that are following some cliff
notes' version of Christianity, mostly centered around money and some
opportunistic politics. On the Islamic side a small group of fanatics has
managed to divide the world in a way that seemed unthinkable 25 years ago and
so on.

------
jayalpha
Extraordinary claims need extraordinary data. We don't have this data.
[https://en.wikipedia.org/wiki/Viking_lander_biological_exper...](https://en.wikipedia.org/wiki/Viking_lander_biological_experiments#Scientific_conclusions)

It is "inconclusive" at best.

~~~
computerex
> Surface water sufficient to sustain microorganisms was found on Mars by
> Viking, Pathfinder, Phoenix and Curiosity;

Ultraviolet (UV) activation of the Martian surface material did not, as
initially proposed, cause the LR reaction: a sample taken from under a UV-
shielding rock was as LR-active as surface samples;

Complex organics, have been reported on Mars by Curiosity’s scientists,
possibly including kerogen, which could be of biological origin;

Phoenix and Curiosity found evidence that the ancient Martian environment may
have been habitable. The excess of carbon-13 over carbon-12 in the Martian
atmosphere is indicative of biological activity, which prefers ingesting the
latter;

The Martian atmosphere is in disequilibrium: its CO2 should long ago have been
converted to CO by the sun’s UV light; thus the CO2 is being regenerated,
possibly by microorganisms as on Earth;

Terrestrial microorganisms have survived in outer space outside the ISS;

Ejecta containing viable microbes have likely been arriving on Mars from
Earth;

Methane has been measured in the Martian atmosphere;

microbial methanogens could be the source;

The rapid disappearance of methane from the Martian atmosphere requires a
sink, possibly supplied by methanotrophs that could co-exist with methanogens
on the Martian surface;

Ghost-like moving lights, resembling will-O’-the-wisps on Earth that are
formed by spontaneous ignition of methane, have been video-recorded on the
Martian surface;

Formaldehyde and ammonia, each possibly indicative of biology, are claimed to
be in the Martian atmosphere;

An independent complexity analysis of the positive LR signal identified it as
biological;

Six-channel spectral analyses by Viking’s imaging system found terrestrial
lichen and green patches on Mars rocks to have the identical color,
saturation, hue and intensity;

A wormlike feature was in an image taken by Curiosity;

Large structures resembling terrestrial stromatolites (formed by
microorganisms) were found by Curiosity;

a statistical analysis of their complex features showed less than a 0.04
percent probability that the similarity was caused by chance alone;

No factor inimical to life has been found on Mars.

~~~
mmazing
“Sure, but where's the evidence?”

~~~
computerex
That _is_ the evidence. Science is often done indirectly. We know that the Sun
is made up of hydrogen gas but no one has been there. We know black holes
exist, and that the big bang took place 15 billion years ago, that atoms are
made up of protons, electrons and neutrons, and that gravitational waves
ripple through spacetime. No one has directly seen these things, but we know
them to be true based on indirect evidence.

Similarly, the above list of facts is indirect evidence for life on Mars.

~~~
ajna91
The person who replied to you was actually making fun on people who claim
there is no evidence.

------
mellosouls
Whatever the evidence, a major factor in this man's belief is likely to be the
emotional attachment to the idea.

It's his life's crowning achievement as the project leader, and seeing
indicators that turned out to be nothing must be a tough thing to come to
terms with.

------
Razengan
Excuse the cliche question, but what _is_ Life?

If we make an AI whose thoughts and communication are practically
indistinguishable from humans, and it controls a bunch of things that affect
the physical world, is it alive?

If there's a disembodied mind somewhere that can think and imagine but never
communicate or interact with anything, is it dead?

What about a human in a coma or permanent dreaming state? What about when they
later wake up?

Okay nevermind thoughts and communication; What if there's an armada of "dumb"
robots, spawned from a single factory, that can't think, only acts according
to preset instructions, but still goes on to affect many things for hundreds
of years, what should they be classified as? Would they be considered
"artificial" life or automatons even if they existed for thousands of years
and their creators were no longer around?

I don't think there is any single absolute criteria to classify all possible
entities that must be out there or could theoretically exist, but the answer
to "What is life?" is probably this:

Whatever other life thinks is life.

~~~
tbabb
Life is that which is subject to Darwinian evolution.

That definition catches every single thing you'd call life, excludes all the
things that clearly aren't, disambiguates some grey cases, and illuminates one
or two new phenomena to be life which you might not have realized.

To be clear, Darwinian evolution means:

\- It makes copies of itself (reproduction)

\- The copies take traits from the original (inheritance)

\- The traits can vary among the copies and between generations (mutation)

\- The copies' ability to make more copies depends on the traits they inherit
(selection)

~~~
Razengan
> _It makes copies of itself (reproduction) ..._

Again, what about species that don't reproduce themselves, but spawn from a
single "factory"?

That factory may be nothing like them. It could be a mechanical factory
producing automatons (with human-level thought if you need that criteria), or
a universally-unique "mother" creature, or even a non-sentient spawning pool
where they spontaneously form every now and then.

If there are entire planets populated by such entities, and they have governed
over many things for as much time as we have occupied our Earth, would you
still classify them as not-life in your dealings with them?

That would be like not considering Taiwan a country. (Sorry, couldn't resist
injecting contemporary political commentary.)

~~~
tbabb
> or a single "mother" creature

How did the "mother" creature come to be? By what mechanism did its complexity
emerge?

There is no known or plausible mechanism by which complex life can arise
without evolution, and technology which does not change its design is (very
appropriately) by the definition above, _not_ life.

~~~
Razengan
> _How did the "mother" creature come to be?_

It could be a human "mad scientist" creating hordes of Pikachus.

Suppose the scientist has also attained biological immortality for himself,
and the Pikachus have spread to multiple planets over thousands of years.

You come upon such a colony planet, but you have no knowledge of their
creator. They display no clues that hint at the scientist's role in their
civilization (for a civilization it has become by now.)

You cannot discern how the Pikachus are coming into existence. Would you
classify them as life? Why not?

How would your interactions with them and their interactions with the universe
be fundamentally different than any other life you encounter?

What if they were robotic instead of flesh-and-fur?

~~~
tbabb
I assume by "spreading" you mean that the Pikachus can reproduce?

Can they mutate? If so, then they satisfy all four boxes and they count as
life.

If the Pikachus are made of cells, they'll certainly mutate/vary, since their
heritable material is DNA, which is quite fragile.

Really, it's hard to imagine having "reproduction" without "mutation" in the
imperfect physical world where errors are possible— I can't imagine any
copying process, even a technological one, which succeeds with perfect
fidelity and 100% probability. So if you have #1, #3 is basically going to be
a given, because the universe is imperfect.

I don't think "what material they're made of" matters much, except that by
definition flesh has to be alive, since it's made of things (cells) that tick
all four boxes.

If the Pikachus don't reproduce themselves, and/or are created with perfect
fidelity every time, then yes, I would call them technology and not life. We
certainly wouldn't say that iPads (Pikachus) coming from a factory ("mother
creature") are alive.

~~~
Razengan
> _I assume by "spreading" you mean that the Pikachus can reproduce?_

No, they're all created by the mad scientist but can think, reason,
communicate, teach, interact, invent and construct perfectly fine on their
own.

> _I don 't think "what material they're made of" matters much ... If the
> Pikachus don't reproduce themselves, and/or are created with perfect
> fidelity every time, then yes, I would call them technology and not life._

So, to distill your criteria for life, it comes down to:

• Species must consist of "individuals" who join in pairs to produce another
individual.

• New individuals must be slightly different from the individuals who
reproduced them.

In other comment [0] you say that you could consider software to be alive:

> _Note that "alive" by the given definition doesn't imply "conscious" or
> "intelligent"_

> _We certainly wouldn 't say that iPads (Pikachus) coming from a factory
> ("mother creature") are alive._

But if an iPad had a software process that connected to another iPad, and they
both commanded the factory to create a new, slightly different iPad, would
they be considered alive? :)

[0]
[https://news.ycombinator.com/item?id=21231043](https://news.ycombinator.com/item?id=21231043)

~~~
tbabb
> Species must consist of "individuals" who join in pairs

Where did you get pairs from? If the Pikachus reproduced by binary fission
(splitting in half and then growing a new half, like cells do), or had 18
genders, they would still evolve. They only have to make copies. Doesn't
matter how.

> No, they're all created by the mad scientist but can think, reason,
> communicate, teach, interact, invent

If they can't reproduce (and/or aren't made of stuff that can reproduce), I
would say complexity of behavior is irrelevant.

For example, the identical iPads coming off the factory line are still
technology, whether they are loaded with simple software or complex software.
The complexity could go all the way up to AI, but they would still be
technology.

Note that we are used to "intelligent" meaning "alive", because the only
intelligent thing we know of at this point in history (us) is alive. But I
think it is perfectly valid to suppose that non-living things could be
intelligent or even conscious.

> So if an iPad [...] created a new, slightly different iPad, would they be
> considered alive?

Yes, under those conditions they would certainly start evolving, and I think
that's a perfectly reasonable line to draw between technology and life. In
this new example, the "phenotype" of the iPads would change in a self-
sustaining way, emergently, independent of any design or intent.

~~~
Razengan
Alright: An individual of an species has to initiate the production of another
individual of that species, and the new individual must have some differences
from the preceding individual.

Do I have it correct?

~~~
tbabb
Yes, but it's not everything. You've got two and a half of the original four
criteria there:

> An individual of an species has to initiate the production of another
> individual

️^ reproduction

> of the same species

It depends on what you're defining to be "the same species", but if we take
that to mean "shares traits with the original", then that's "inheritance".

> new individual must have some differences

^️ mutation

The one you're missing is "selection"— that the future success at copying
depends on the traits you inherited.

If you have variable traits, but they don't at least indirectly result in
either more or fewer copies, then there is no cause for some traits to become
more prevalent than others in the population and evolution won't occur. You'll
just get a jumble of random traits without any trend toward fitness (aka more
efficient copying).

It is a fact of nature/mathematics that those four rules are necessary and
sufficient for evolution to occur. If you set them up, evolution _will happen,
guaranteed_. Those rules constitute an _algorithm_ , carried out by the laws
of nature on the substrate of physical matter, whose result is evolution— a
trend toward increasing reproductive fitness.

------
aazaa
> On July 30, 1976, the LR returned its initial results from Mars. Amazingly,
> they were positive. As the experiment progressed, a total of four positive
> results, supported by five varied controls, streamed down from the twin
> Viking spacecraft landed some 4,000 miles apart. The data curves signaled
> the detection of microbial respiration on the Red Planet. The curves from
> Mars were similar to those produced by LR tests of soils on Earth. It seemed
> we had answered that ultimate question.

This article does a poor job of explaining the experiment in question:
"Labeled Release" (LR).

According to Wikipedia:

> ... In the LR experiment, a sample of Martian soil was inoculated with a
> drop of very dilute aqueous nutrient solution. The nutrients (7 molecules
> that were Miller-Urey products) were tagged with radioactive 14C. The air
> above the soil was monitored for the evolution of radioactive 14CO2 gas as
> evidence that microorganisms in the soil had metabolized one or more of the
> nutrients. Such a result was to be followed with the control part of the
> experiment as described for the PR below. The result was quite a surprise,
> considering the negative results of the first two tests, with a steady
> stream of radioactive gases being given off by the soil immediately
> following the first injection. The experiment was done by both Viking
> probes, the first using a sample from the surface exposed to sunlight and
> the second probe taking the sample from underneath a rock; both initial
> injections came back positive.[1] Subsequent injections a week later did
> not, however, elicit the same reaction, and according to a 1976 paper by
> Levin [author of the linked article] and Patricia Ann Straat the results
> were inconclusive.[12][13] In 1997, Levin, Straat and Barry DiGregorio co-
> authored a book on the issue, titled Mars: The Living Planet.

[https://en.wikipedia.org/wiki/Viking_lander_biological_exper...](https://en.wikipedia.org/wiki/Viking_lander_biological_experiments)

To recap, martian soil was incubated with small organic molecules bearing a
radioactive label. A chemical process that converted them into CO2 would give
off some radioactive gas. The gas was detected by both landers the first time
the experiment was run, but not the second time.

It should be kept in mind that non-biological processes can also convert small
organic molecules into CO2. Simple combustion will do this, for example.

This possibility is discussed later in the Wikipedia article (but not in the
linked article):

> Despite the positive result from the Labeled Release experiment, a general
> assessment is that the results seen in the four experiments are best
> explained by oxidative chemical reactions with the Martian soil. One of the
> current conclusions is that the Martian soil, being continuously exposed to
> UV light from the Sun (Mars has no protective ozone layer), has built up a
> thin layer of a very strong oxidant. A sufficiently strong oxidizing
> molecule would react with the added water to produce oxygen and hydrogen,
> and with the nutrients to produce carbon dioxide (CO2).

However, this does not explain the discrepancy between the first and second
test. And it leaves open the question of why both landers' experiments gave
the same odd result (first test positive, second test negative).

The small organic molecules used as nutrients were those produced in a famous
lab simulation of early earth. Its results showed that many of the basic
building blocks of life could be formed by passing an electrical current
through gases thought to be present in the early Earth atmosphere.

~~~
01100011
It seems like one could replicate this experiment on earth and verify non-
biological origins for the observed results. I'm pretty sure we're familiar
with the composition of martian soil by now. Create a sample with similar
composition, blast it with UV rays in an atmosphere similar to Mars, and
subject the soil sample to the same test.

~~~
SubiculumCode
Why isn't just a plain old microscope used to detect microbial life?

~~~
cypherpunks01
I'm guessing this could be a potentially much faster method to search the
space, if there were not too many organisms up there? If you used a robot to
prepare microscope slides of random soil samples, it could take an exceedingly
long time to get lucky enough to find one, even if there are a lot around.

------
chkaloon
I wonder if there is an incentive to NOT find life there because of what that
discovery might do to slow industrialization and colonization plans. Do we
need to conserve that life? Do we need to set up preserves that are off limits
to development? Opens a big can of worms (or bacteria) that I imagine some
would rather see kept closed

~~~
soup10
realistically mars is way more interesting if its more than a boring rock

~~~
ncmncm
Even with microbes it would be a boring rock.

Anybody who thinks they want to move there should camp in Antactica for ten
years, first.

~~~
hanniabu
And because people settled in Antartica it's no longer the miserable
experience it used to be. These are pioneers, they do things that are had,
they pave the way for the rest of humanity.

~~~
ncmncm
There is no migration to Antarctica. Nothing done by people there makes it any
easier for somebody who wants to move there, because if your application for
research is rejected, you stay out or set up somewhere far away.

------
yummybear
But if the CLR comes back positive, doesn’t that still mean there’s room for
“it could be some unknown nonbiological process”. Wouldn’t saying with
certainty that there is life on mars need somerthing like a microscopic image
of cells dividing?

------
claudeganon
Good book about it:

[https://en.m.wikipedia.org/wiki/Sandkings_(novelette)](https://en.m.wikipedia.org/wiki/Sandkings_\(novelette\))

------
therealbilly
Here's the deal. There seems to be a default mode of behavior where people
automatically reject news that conflicts with the status quo. In this case,
these people are senior scientists not involved in the original mission. It's
very unfair. Breakthroughs in knowledge could be happening right beneath our
noses and people (not involved in the project), are actively surpressing or
invoking pretzel logic to belittle the findings.

------
NoPicklez
It seems like finding life on another planet is held to secrecy, but in my
mind wouldn't a country want to take credit for finding the first signs of
life outside of Earth? And therefore, if a country was to find and confirm
life of another planet wouldn't they report it immediately?

------
Causality1
I'd be flatly amazed if impact ejecta never carried any microorganisms from
earth to Mars.

------
sandGorgon
> _Our nation has now committed to sending astronauts to Mars. Any life there
> might threaten them, and us upon their return. Thus, the issue of life on
> Mars is now front and center._

I'm pretty sure this is the whole point of the article.

------
speedplane
Science is not about finding life per-se, it's about satisfying curiosity.
Articles like these conflate real science (satisfying human curiosity) with
finding life on other planets (we're not alone). Of course, finding life on
another planet would be an amazing discovery, but for any true believer in
science, it would just be the beginning of a million more questions, not the
end goal.

~~~
sidcool
While Scientific discovery would never stop, a milestone like this would be
significant. And it would warrant awe.

------
outworlder
Lots of conspiracy theories here.

Planetary Protection is already a thing, even though we haven't found anything
yet.

------
edoceo
"microbial respiration on the Red Planet"

I want to believe.

------
ropiwqefjnpoa
IDK, what would be the motive to hide that?

~~~
chadcmulligan
To hide the lizard peoples secret base

~~~
dang
Please stop posting unsubstantive comments here.

------
starvingbear
> The curves from Mars were similar to those produced by LR tests of soils on
> Earth. It seemed we had answered that ultimate question.

Maybe it was on earth

------
hirundo
"Our aspirational goal is to send our first cargo mission to Mars in 2022. The
objectives for the first mission will be to confirm water resources, identify
hazards, and put in place initial power, mining, and life support
infrastructure. A second mission, with both cargo and crew, is targeted for
2024" \-- spacex.com/mars

Maybe NASA should book space for a biologist on that flight. A botanist would
do.

~~~
dwoozle
Do you really need a botanist on board? I would think you need space travel /
survival / engineering hands on deck who then gather samples and bring them
back. A botanist isn’t going to be able to do much on Mars that she can’t do
on Earth.

~~~
tootie
A botanist was the protagonist of The Martian.

~~~
jorvi
And an antagonist on the TV series 'Mars'!

~~~
ksaj
I'm guessing that means we're hopelessly off topic by now. Kinda like Reddit,
but slower and less pathetic.

------
sgt101
The search for life is the way NASA gets funding.

If life is found NASA will not get funding.

Therefore NASA is doing all the science it can before it does a test for life.
At least we will be able to say something about what it is and the context
that it's in.

Then the plug will get pulled.

~~~
wickedsickeune
I highly, highly, doubt that. If life was found, I expect that the amount of
money invested in studying it, would be orders of magnitude what they are
getting now.

------
RobertRoberts
Science becomes corrupted when the research focuses on finding proof of and
ideal instead disproving it.

There are no aliens. With the money wasted on looking for aliens we could have
saved millions of lives with clean water, shelter, food and education.

Scientists need to stop deluding themselves and tricking congress into funding
pet projects that are so far fetched they border on fraud.

~~~
sidcool
"Ancient explorers should never have ventured on ships to find new lands, for
the cost of that could have been used in their countries to better serve the
poor" /s

~~~
transreal
If you're taking about the European explorers - they didn't - they went
looking for new trade routes to lands they already knew about. It was about
commerce, not exploration. Only after someone "hit it big" (Columbus) did
others follow because they realized the commercial opportunities of finding
"new" places.

The Polynesians sailing into the unknown Pacific is a different case, but that
was most likely (based on what I've read) a situation of "the poor" venturing
out to find new lands for themselves, not well funded expeditions paid for by
existing kings.

