Possible Evidence of Martian Bacteria

half-seas-over writes "NASA issued a very interesting press release today. It highlights a recent study that compared tiny magnetite crystals in the Allan Hill meteorite to similar magnetite crystals that are created here on Earth by bacteria (who use the magnetite as a compass). The study (abstract available here (PDF) from this site) uses fairly strict criteria to determine that 25% of the magnetite content of the meteorite was created by ancient (>3.9Gyr ago) martian bacteria... either that or there is some strange natural process that makes very pure, isolated magnetite crystals that we haven't imagined or seen on Earth which is present on Mars. We'll have to wait and see what happens next, 'extraordinary claims require extraordinary evidence' -Carl Sagan."

Comments

And so on

[Dexter77]

...
"Martian bacteria leaks out of NASA lab"
...
"Mutated animals sighted near NASA lab"
...
"Strange disease spreads through continent"
...
"President Bush announces state of emergency"
...
"President Bush renounces state of emergency"
...
"USA replaces national anthem with strange beeps and Coca-Cola switches water to sulphure dioxode in its drinks"

Easy tiger...

[MADCOWbeserk]

Seems like their is a Major life on mars discovery every few months. Most of the time they are disproven within a couple of weeks. Take the wait and see approach and see if this "discovery" holds up to peer review.

Science press releases are usually half bs.. A good way to get research funding.

Re:Easy tiger...

[corleth]

Not true: very little (if any) of the life on Mars findings have been proven or disproven. All that is happening is that some scientists are presenting their evidence that supports the hypothesis that life has existed or even does exist on Mars. Other scientists are scrutinising this evidence and poking holes in their analyses. This is part of the scientific process and only to be expected. What is needed is a new form of data. We can argue about magnetite in Mars meteorites for years but it probably won't solve anything. What we need is a fresh sample, that hasn't been superheated on impact and re-entry.

How all this is portrayed in the media is often misleading and, yes, that is sometimes the fault of the scientists as much as the science journalists. The truth is that the media tends to dumb down science for the general public in the belief that real science is too boring for them. Whether this is justified or not is a matter of opinion.

Scientific press releases can be a good way to get research funding. It is also a very dangerous game to play, as scientists are often misquoted to their expense.

-Karl

Dr Karl Mitchell
Planetary Science Research Group
Environmental Science Dept.
Lancaster University
UK

Crystals

[Subcarrier]

Sprinkle some salt on your dinner and, no matter how careful you are, a little will always wound up on the table. -- JHVH, Day 7

"extraordinary claims..."

[tlambert]

"When you eliminate the impossible, whatever you have left, no matter how improbable, must be the truth." -- Sherlock Holmes ("The Beryl Coronet", Arthur Conan Doyle).

Dueling quotes on deductive reasoning at dawn! I shall see you on the morrow, sir!

-- Terry

Re:Mars rock

[corleth]

The rock is from Mars. Atmosphere isotope ratios are unambiguous in such cases. Every planet has it's own "signature" that, with the right equipment, is possible to detect. This was demonstrated ages ago by Monica Grady and others in the UK.

You're correct that it's easier to get a meteorite from a smaller body, and we do get loads of them (positively identified Martian meteorites number in the dozens rather than the thousans). However, Mars is massive and has had many massive impacts. The amount of material ejected from it's surface means that it would be amazing if none had reached the Earth.

Also, regarding life, it's unlikely that life would have evolved on any body that did not have liquid water. Liquid water has always been unstable on asteroids, whereas there have significant periods of Martian history (likely when the impact occurred) where liquid water was thought to be stable, possibly over hundreds of millions of years. In fact, there are even points on present day Mars where, for a limited period during the year, water can be stable on the surface. Of course, if you believe Fred Hoyle, life could be everywhere, but, based on an Earth model, life seems far more likely to have evolved on Earth and/or Mars.

The evidence for this being a result of biological activity is still highly ambiguous however, which is why we need to get samples back from Mars.

-Karl

Dr Karl Mitchell
Planetary Science Research Group
Environmental Science Department
Lancaster University
UK

Alein Bacteria?

[MadFarmAnimalz]

How utterly boring. What happened to the 'superior intelligences' theory?

NASA, we demand smart aliens, with tentacles and bug eyes and all. Don't you scientists read comic books?

You're not doing your job. Bacteria? If these are the only aliens you can come up with then LOOK HARDER.

Harumph.

mutter mutter misappropriated tax dollars mutter

(press release) = (science * 100)

[dankelley]

This Nasa press release is closer to tabloid reporting than it should be, and it does a disservice to the scientists.

In the press release we read " new evidence confirming that 25 percent of the magnetic material in the meteorite was produced by ancient bacteria on Mars. ... This means that one-quarter of the magnetite crystals ... in Martian meteorite ALH84001 require the intervention of biology to explain their presence. "

The words "confirm" and "require" are very strong, indeed.

However, in the abstract of the scientific report we read something quite different: " On Earth such ... magnetites are known to be produced by magnetotactic bacteria. We suggest that the observation ... are [sic] both consistent with, and in the absence of terrestrial inorganic analogs, likely formed by biogenic processes."

So, the scientists suggest that something is consistent with a proposition, and the press-releasers convert that into confirmation of the proposition.

Sure, scientists' language often needs to be modified for public consumption, but here we have a case of changing the entire thrust of the story.

This sort of mistake would be unacceptable from a high-school science student, and that makes me wonder whether this exaggerating rewriting might have been deliberate. I remember a story of crying "wolf" ...

Head Tail Tail Head HTTTTHTHHTHT Edge

[SEWilco]

"In the past 100 years how many times have people discovered new physics laws vs discovered life on other planets?"

In the past 100 years how many times have people built houses vs built computers? Obviously there are no computers because so many houses have been built. Slashdot vanishes in a cloud of irrelevant improbabilities...

The probability of an event happening does not affect whether the event actually happens.

For that matter, we are here. The obvious choices for the existence of life here are:

• Life here was created by random chemical/physical processes. Probability unknown.["Here" is this solar system, whether Mars or Earth]
• Life here is an extension of existing life in this galaxy. Probability unknown, but allows much longer time frame and once it happened once it can spread.
  • Panspermia.
  • Random cause: Bacteria or DNA from other solar systems seeded our biology.
  • Directed cause: Life forms in other solar systems sent primitive life to other solar systems. Does not require intelligence, because a space-seeding plant is an increase in the probability of intersystem seeding.
  • Gardening: Intelligent life seeded our solar system.
• Miracle: We just appeared here. Probability unknown. Several conflicting events recorded.

There are several possibilities for our own life forms. The possibilities of our origin give hints as to the chances of life existing elsewhere, but are not proof. We need more data.

This data about life existing on Mars suggests several modifications in theory:

• Life was able to be created outside the conditions at Earth's orbit. If Mars was very different from old Earth when life formed on Mars, the probability of random life creation is increased due to a widening of the definition of a suitable environment.
• Life may have been created in two places within this single solar system. This suggests that the probability of random life creation is fairly large. It is possible that life is very unlikely and the coin just happened to land on edge twice here, but the suggestion is still toward a higher probability of life.
• If life was created on Mars and travelled to Earth, the probability of panspermia tends to be higher. Evidence of life which can survive space increases the probability that life can travel between solar systems (ignoring the possibility of close approaches by another solar system or rogue planets).

Some of these possibilities are mutually exclusive. If life on Earth was seeded by Mars then although the possibility of Panspermia is increased, an increase in the possibility of random life is then not suggested. We then still have only one example of the creation of life in this solar system, it merely happened on Mars instead of the previously assumed location of Earth.

A non-Mars item affecting life probabilities: Recent evidence suggests that life existed on Earth only a short time after Earth cooled. Although the probability of life being randomly created on Earth is unknown, a shorter time of appearance is a hint at a larger probability. Only a hint, as with a single event it is possible that a nearly impossible event just randomly happened here. The same situation is present if life appeared on Mars shortly after it cooled. If life appeared independently in both places shortly after it cooled, that is two hints at a larger probability.