Firstly, space-originating complex molecules are nothing new. Amino acids have long been known to exist in extraterrestrial sources, such as meteorites (e.g. [1, 2]) and interstellar clours [3]. Thus, it is not surprising that they form rather "easily" (whatever that means) like in the impact simulations like in the news piece you linked to. However, the formation method as such is quite interesting, and it does give a clue on the possible abundance of amino acids on early planetary surfaces.

The answer to your question depends entirely on what is meant by "extreterrestrial". During planetary accretion everything comes from space. Whether the amino acids are already present in the body falling from space and come straight from space, or if they form at the instant of impact, may not be that important. I suspect there are several delivery methods - and quite possibly there are several ways of forming them in-situ on the planetary surface from simpler molecules.

The main *slight* problem is actually making anything living from mere amino acids. The latter are, after all, quite simple in comparison to anything that can be considered even remotely "alive". The machinery needed for self-replication is quite extensive. Even virus particles, virions, are much more complex than just amino acids.

[1] http://www.nature.com/nature/journal/v228/n5275/abs/228923a0.html

[2] http://www.nature.com/nature/journal/v389/n6648/full/389265a0.html

[3] http://physicsworld.com/cws/article/news/2003/aug/11/amino-acid-detected-in-space

Thanks Professor Jarmo

I'm definitely no professor. :) But glad to be of help.

Dear colleagues, Martins' paper in Nature Geoscience is certainly relevant. Previous evidence from carbonaceous chondrites studies was suggesting that some hydrated groups exhibited important concentrations of amino acids. Different origins were proposed as e.g. the own disk, but it is now plausible that complex organics formed in the matrix of these materials when the ice-bearing progenitor asteroids were shocked in the aftermath of impacts. Probably a significant part of these objects formed in the outer disk reached the terrestrial planets at the time of the Late Heavy Bombardment (LHB). This scattering event of bodies has been explained with the Nice model due to the inwards migration of giant planets occurred between 3.9 and 3.8 Gyrs ago. Consequently, the relevance of organic materials and their role to enrich the surface of Earth depends of the different pathways of these materials, the collisional processing that they experienced, and their survival during atmospheric disruption and impact delivery. For more details and an update you also have our recently published book in Springer titled: "The early evolution of the atmospheres of terrestrial planets".

http://www.springer.com/astronomy/extraterrestrial+physics%2C+space+sciences/book/978-1-4614-5190-7

We did an estimate of the amount of organics delivered by meteoritic material during the late heavy bombardment and found it fairly lacking, even if you use a high meteorite flux:

Pasek, M., & Lauretta, D. (2008). Extraterrestrial flux of potentially prebiotic C, N, and P to the early Earth. Origins of Life and Evolution of Biospheres, 38(1), 5-21.

The salient result from this paper was that you might expect about 10^5 kg of carbon falling in from carbonaceous chondrites each year, though maybe up to 10^9 kg if you invoke interplanetary dust particles (IDPs) as a source. However, IDPs are spread world-wide, and hence you would only expect to find about 1 kg of organics per km^2.

Now, phosphorus from meteorites, that might be different! Meteorites do actually drop a fair bit of phosphorus to the early earth, and we see some evidence for this in old earth rocks:

Pasek, M. A., Harnmeijer, J. P., Buick, R., Gull, M., & Atlas, Z. (2013). Evidence for reactive reduced phosphorus species in the early Archean ocean. Proceedings of the National Academy of Sciences, 110(25), 10089-10094.

Grateful thanks to Prof. Jarmo , Prof. Mathew and Professor Josep for very useful references and discussion.

Hello everybody,

I've been working with amino acids and have heard before the story on the detection of glycine in the interstellar medium. It is concerning ref. 3 above:

[3] http://physicsworld.com/cws/article/news/2003/aug/11/amino-acid-detected-in-space

So, several years ago I read the paper and went to discuss the good news with my colleague. I was glad that besides meteorite the simplest one can be also detected by spectroscopy in space - it is important fact for my experiments. However, I was told that the studies were later disproved ... and indeed and after some searches I found the paper:

A rigorous attempt to verify interstellar glycine.

Astrophysical Journal

Volume619

Pages914-930

DOI:10.1086/426677

So, it's pity but the question is still opened. See also for example:

About the detectability of glycine in the interstellar medium.

Lattelais, M.; Pauzat, F.; Pilme, J.; Ellinger, Y.; Ceccarelli, C.

Astronomy & Astrophysics

Volume532

PagesA39/1-A39/7

Journal

2011

DOI:10.1051/0004-6361/201016039

Kind regards!

We are made out of pieces that exist throughout the universe. However the origin of life appears as an emergent property of the system rather than one imposed on the system by external influences. Here I share with you a recent article of my own authorship, where it demonstrates that the probability and the characteristics for the origin of life tends to zero than to one. 

Article Evolution through the stochastic dyadic Cantor Set: the uniq...

Thanks for the interesting paper.

Different view on the role of extraterrestrial materials in the origin of life.

http://www.pnas.org/content/112/3/657.full.pdf

Thanks guys, please also note our model and the evidence that we published last year in Nature Sci. Rep. about the catalytic action of carbonaceous chondrite (CC) minerals in presence of hot water and formamide. Our paper, in cooperation with Prof. Raffaele Saladino in Tuscia, demonstrates unique catalytic properties of CCs. The flux of such materials were huge in the Hadean and dominant according to the CM-rich implanted materials in Moon rocks. Our research paper was selected to be open, so it is fully accessible at:  http://www.nature.com/articles/srep38888

http://www.nature.com/articles/srep38888