Origins of life on Earth
A while back I saw a program on TLC, or I think it was TLC :?: .
Anyway, The show was about how life could have been "seeded" on Earth by Comets or Asteroids. This got me thinking, and researching.
The biggest argument against this theory is that the components that make up life ,ie the amino acids and proteins and other organic materials, could not survive the impact.
Well, A NASA-supported experiment reveals that complex molecules hitchhiking aboard a comet could have survived an impact with Earth.
"Our results suggest that the notion of organic compounds coming from outer space can't be ruled out because of the severity of the impact event," says Jennifer Blank, a geochemist at the University of California, Berkeley. Blank and colleagues simulated a comet collision by shooting a soda-can sized bullet into a metal target containing a teardrop of water mixed with amino acids - the building blocks of proteins.
Not only did a good fraction of the amino acids survive, but many polymerized into chains of two, three and four amino acids, so-called peptides. Peptides with longer chains are called polypeptides, while even longer ones are called proteins.
I think that is amazing that not only did those materials survive but the impact was actually instrumental in fusing those materials into more complex materials.
Basically, in the experiment, they fire a steel capsule filled with the basic organic materials that make up the cells of animals and plants("life"). They fire this capsule at 1.6 kilometer-per-second into a target in a chamber that is pressurised to 200,000 times atmospheric pressure. This simulates the impact of the rock or comet on the Earth. Like I said, not only did the materials survive they actually combined to make more complex organic materials. Wow.
When they froze the capsule to simulate a comet the survival rate went up even higher for these materials. Also the addition of water actually is a greater enabler for the evolution of life.
The next question is , "how does this material get on the comet or space rocks."
Well, Astronomers have detected many kinds of organic molecules in space, floating in clouds of gas or bound up in dust particles. They range from the simplest - water, ammonia, methane, hydrogen cyanide and alcohols, including ethyl alcohol - to more complex molecules.
We have even ,just recently, found sugar in space.
This sugar is known as Glycolaldehyde, an 8-atom molecule composed of carbon, oxygen and hydrogen, can combine with other molecules to form the more-complex sugars Ribose and Glucose. Ribose is a building block of nucleic acids such as RNA and DNA, which carry the genetic code of living organisms. Glucose is the sugar found in fruits. Glycolaldehyde contains exactly the same atoms, though in a different molecular structure, as methyl formate and acetic acid, both of which were detected previously in interstellar clouds. Glycolaldehyde is a simpler molecular cousin to table sugar, the scientists say.
http://science.nasa.gov/headlines/y2000/ast20jun_1.htm
I think this is a good step forward in explaining the origins of life here on Earth.
At one time people thought the Earth was flat.
That was proven false.
They thought the Earth was the center of the solar system.
That was proven false.
Maybe the Earth isn't the center of Biology as we once thought.
Interesting stuff, I think.
I found the source of the experiment online.
http://science.nasa.gov/headlines/y2001/ast05apr_1.htm