That Mars rock a few years ago?

A few years ago it was in the news that a meteor from Mars showed that life actually started on Mars. Then it turned out to be a just another hoax, right?

Also I still hear people claiming that there are amino acids in meteors, but I can’t help wondering if this is just lingering from that old hoax.

It wasn’t a hoax, and there is still debate on whether or not the microscopic structures discovered in the metorite are fossilized bacterialike lifeforms or not. More information here.

It wasn’t a hoax, just a contentious theory that provoked a lot of debate. Nothing was proven either way. And it wasn’t suggested it was proof that life on Earth started in Mars. Just that a form of life may have been on Mars.

That’s interesting. Although NASA is of course not exactly an unbiased source. It does say they found “organic molecules” though I’m clear exactly what that signifies. No offense, but when reading this article a quote kept popping into my mind. “To a man with a hammer, everything looks like a nail” -(Who said this? I don’t remember.)

I don’t think there is any conflict of interest or bias, beyond the natural tendency of all scientists to want to make interesting new discoveries. The presented images and analyses are in themselves interesting and important, and the suggestion that it indicates life is just that, a suggestion. You can read the original paper here and judge for yourself:

And “organic molecules” doesn’t mean nearly as much as a layman might think. Chemists long ago gave up on trying to define “organic” in terms of life (first challenge: Define “life”), so nowadays, “organic molecule” just means “molecule which contains carbon”. Even amino acids, the particular oganic molecules which form the building blocks for proteins, aren’t particularly exciting: They’re found all over the place in the Universe, and we’re quite certain that they can be formed without life, since we’ve done so in the lab using simple experiments. So just finding amino acids in a meteorite is interesting, but it’s not even close to proof that Mars once had life.

The biggest points of contention in the Mars meteorites were small spherical structures which looked like they might be fossilized cells, and small magnetic structures similiar to those produced by some Earthly bacteria. But it’s not implausible to suppose that those structures were both formed in non-biological processes, even if nobody is quite sure how. In the end, we come down to the skeptic’s mantra that extraordinary claims require extraordinary evidence. Life on Mars is an extraordinary claim, but the evidence for it is all ordinary at best, so we ought still to assume that it’s not life.

Here’s a little more information about the type of “organic” molecules found on the Mars meteorite:

If you meant you were unclear about what is meant by organic molecules, they are simply carbon-based molecules, such as those found in living organisms.

There is nothing magical about organic molecules though - they can be produced by inorganic processes. (It was long believed that this was impossible, until Friedrich Wöhler synthesised urea, an organic compound, from inorganic starting products in 1828.