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Having read the article you linked, it appears that while they admit it possible that
the amino acids were all contaminate, but exceptionally unlikely.
While it would be best to take samples directly from space, the evidence and
techniques that they uncovered and employed make it extremely unlikely that all
the amino acids present were contaminate from earth.
So while it is always good to remain sceptical, it appears in this case that the
evidence supports an extra-terrestrial origin for these organic molecules.
Originally posted by googlefudgeThat is interesting. I wonder how the molecules survived the heat of the entry.
Having read the article you linked, it appears that while they admit it possible that
the amino acids were all contaminate, but exceptionally unlikely.
While it would be best to take samples directly from space, the evidence and
techniques that they uncovered and employed make it extremely unlikely that all
the amino acids present were contaminate ...[text shortened]... this case that the
evidence supports an extra-terrestrial origin for these organic molecules.
Here is a picture of one of the Almahata sitta meteorite.
http://apod.nasa.gov/apod/ap090328.html
Originally posted by mlpriorThe molecules would survive because the time of entry was so short. Remember, meteorites don't behave like space shuttles, which are guided to land in a controlled manner such that the flight path is lengthened to about 15 minutes to slow down the craft. A meteor coming in to Earth just follows the kinetics of its flight path come hell or high water and so is in the atmosphere for a much shorter time so the organics inside just don't heat up much.
That is interesting. I wonder how the molecules survived the heat of the entry.
Here is a picture of one of the Almahata sitta meteorite.
http://apod.nasa.gov/apod/ap090328.html
Kind of like putting a frozen french fry in a hot oil fryer. Compare the time it takes to cook a regular thawed out french fry to a frozen one. The outer layer will for sure get hot but the inside is going to take longer to cook.
Originally posted by sonhouseThose meteors are 40% to 50% iron, they are going to have a very high thermal conductivity. If the outer surface is hot enough to melt iron, you can bet the inside is pretty hot also.
The molecules would survive because the time of entry was so short. Remember, meteorites don't behave like space shuttles, which are guided to land in a controlled manner such that the flight path is lengthened to about 15 minutes to slow down the craft. A meteor coming in to Earth just follows the kinetics of its flight path come hell or high water and so ...[text shortened]... zen one. The outer layer will for sure get hot but the inside is going to take longer to cook.
Originally posted by mlpriorThere is one thing you are forgetting: Ablation. The early heat shields made for say, the Mercury astronauts had a shield on the business end (the part that takes the heat of entry) that heated up when going through the atmosphere at orbital velocities and bits of it flaked away, taking the re-entry heat with it.
Those meteors are 40% to 50% iron, they are going to have a very high thermal conductivity. If the outer surface is hot enough to melt iron, you can bet the inside is pretty hot also.
That also happens with meteorites, the outer layers ablate away taking a lot of heat with it. That is why organics in the center can survive entry into Earth's atmosphere.