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

zZzZz

[Anonymous Coward]

There's already lots of possible evindence, wake me up when there's hard evidence.

Not again.

[palfreman]

I can't believe the space guys are digging up this corpse again. The fact is, they are talking about dust. Not living examples, not any scientifically meaningful examples , just some extremely small "magnetic crystals" that resemble other tiny magnetic crystals found on earth, and probably everywhere in the universe, living or not.

This is juts a rehash of that nonsense about them claiming to have found "tiny fossilised bacteria" which also turned out to be dust, non-living, never living.

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:"extraordinary claims..."

[abreauj]

"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).

This works fine if you never make mistakes, you can be sure you've really examined every possibility, and you always wind up with exactly one remaining explanation. However, the only place that ever occurs is in fiction.

In reality, there's always a strong chance that you've failed to consider some possibilities, or you've declared impossible something that actually is possible, or that after eliminating the impossible you're left with either zero or multiple possibilities.

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.