Genetic Building Blocks Found In Meteorite

FiReaNGeL writes to tell us scientists have confirmed that the components of genetic material could have originated in a place other than Earth. A recently published report explains how uracil and xanthine, two basic biological compounds, were found within a meteorite that landed in Australia. From Imperial College London: "They tested the meteorite material to determine whether the molecules came from the solar system or were a result of contamination when the meteorite landed on Earth. The analysis shows that the nucleobases contain a heavy form of carbon which could only have been formed in space. Materials formed on Earth consist of a lighter variety of carbon."

Comments

Re:Wow.

[Anonymous Coward]

Well, yeah thats what I meant. It would come as a surprise to me to learn that even the building blocks of life came here, rather than being home grown. And thats what this seems new evidence seems to support. There is no support for that idea at all. Nothing has eliminated the options that the building blocks of life formed here in isolation or that some of the building blocks of life formed here and were supplemented with meteorite material. In fact, I think it is highly likely that the building blocks formed here in isolation just due to the volume comparison problem. The early Earth after the ends of the bombardment phase was more than capable of forming carbohydrates, nucleobases, and amino acids, especially with free water and shitloads of carbon and nitrogen in a very electrically active atmosphere. It also had orders of magnitude more volume to perform these actions and didn't have to worry about atmospheric entry. Compared with the ideal conditions of the early Earth, it is pretty unreasonable to say that this evidence supports extraterrestrial formation of these critical chemicals. For every carbohydrate, nucleobase, or amino acid that survived entry to the atmosphere, there were probably billions formed naturally in Earth's chemical reactor.

Re:Let's go over the line...

[drinkypoo]

I don't think that it's necessarily a given that any life within a rock entering the atmosphere will be baked to a crisp, depending on the ablative properties of the body in question. Given that we've already seen evidence that fungus, mold spores, and bacteria can all survive prolonged exposure to vacuum, it would not be especially surprising if actual life came here... or, for that matter, has already left here. Numerous scenarios have been envisioned for Earth's past which involve a serious encounter with a major impactor.

Re:Statistically more probable life started in Spa

[plasmacutter]

the so called hostile temperatures on earth are nothing compared to the hostility of the environment in space.

massive radiation, shockwaves, coronal mass ejections, MASSIVE extremes of heat and cold, and very importantly, the tendency for water to remain in a vaporous or solid form rather than liquid because of the lack of pressure.

Not to say the first dna fragments, amino acids, or single celled life forms could not have come from space, but they had to develop on some body with enough gravity and atmospheric pressure to host some liquid water water.

This characteristic need for liquid water is too fundamental to have simply arisen after this life came to earth.

Re:Wow.

[Pvt. Cthulhu]

Whole microbes surviving in an airless, nutrientless, radiation-saturated enviornment is not unprecedented. The Apollo 12 crew found scores of living streptococcus mitus doing just fine on the Surveyor probes on the moon, which had been there for three years. While its doubtful whole cells came here and populated the planet, it also seems unlikely that the Earth alone provided all the ingredients.