Might Mars Contain Life?

stagmeister writes "According to the BBC, the Viking probes to Mars in the 1970s "detected strange signs of activity in the Martian soil - akin to microbes giving off gas," and that while those findings were not acknowledged as proof of life then, "in 1997, reached the conclusion ... that the so-called LR (labelled release) work had detected life." At the same time, the British are launching a probe to try to find life on Mars."

Not a new controversy

[Cujo]

This has been batted around for several years now. It's an interesting controversy, since the scientific community studying Mars life has seen a lot of turnover since then. We're going to have to wait for the new data.

Carl Sagan said no

[mao che minh]

In one of Carl Sagan's books (I forget which one) he talks about these findings - he helped design the test. Although seemingly compelling, even he himself concluded that the results were incorrect (I just can't recall why). I wish I was at home so I could check Cosmos and Billions and Billions, I know that it is one of those books. Anyone have these books handy?

Also

[GreenJeepMan]

Also launching this month is the "2003 Mars Exploration Rover Mission" It includes two rovers that can treck signigantly further then the previous rover sent. Check it on their web site: http://mars.jpl.nasa.gov/missions/

Both of these missions land later this year / January. They'll be providing more information about Mars over the following year then have gathered in total over the past 50. That is assuming they work. :-)

Also not a new story

[missing000]

Yep, its a dupe!

I quickly found this [slashdot.org] by doing this [slashdot.org].

Next time, please search [slashdot.org] before you post.

Re:Sagan

[Anonymous Coward]

Um, have you ever heard of Bayesian statistics? Nothing in science is entirely proven, it is all just a question of our degree of certainty. The type of statistics which is normally done give us a "confidence level" which represents that chance that our results would have happened randomly and says nothing explicitly about the chances that our hypothesis is true. If we want to actually find the probability that our hypothesis is true, then we have to use estimates of prior probabilities (using Bayes's formula) to get even a guess at those probabilities.
E.G. If I tell you that I have a weighted coin, flip it 10 times, and get all heads I have a weighted coin. If I tell you that I can use telekenesis to control the outcome of a coinflip, flip the coin 10 times and get all heads, I have a weighted coin. The strength of the evidence was just as strong for each one statistically, but due to the nature of the claims one is justified by the data and one is not.

Re:Carl Sagan said no

[Yunzil]

No, that's not what the parent was talking about. Mars is a dry planet now, but there is evidence of liquid water in the past. So the idea was that the recipe to find dormant organisms would be "add water". The Viking landers did an experiment where they took a scoop of Martian dirt, put it in a container, and added a nutrient broth. The goal was to look for gases coming from the dirt which typically are produced by living things.

So, the landers landed, did the experiment, and immediately detected a whole bunch of the gases. Woohoo, life! Well, not really. They examined the data and decided the results were due to some unusual chemistry, not living organisms.

The experiment you're talking about produced amino acids and was done here on earth by Miller and Urey, not Sagan. :)

Re:Where's the Proof?

[Anonymous Coward]

I know Dr Levin and he is not crazy, hes a
very nice guy convinced(and rightly so) that
the LR results on Viking were discounted for
poor reasons. My understanding of what happened
is that someone with more pull at NASA said that
the same posetive results could result from an
inorganic reaction and went on to present a
REALLY unlikely inorganic chemical situation
that would produce a LR life sign. Further
research and evidence has shown that the
inorganic processes put forth by this other
guy were increasingly impossible.

I wouldn't be surprised if NASA decided not to
include Dr Levin's new experiment because it
would underline the foobar they pulled by
ignoring the LR experiment.
Just my opinion, but I also happen to be right.