How life came to Earth
Some of the earliest posts of this blog dating back to 2006 suggested that seeds of life were brought to earth by comets. The theory can be reached quickly by clicking archive links in the side bar. The theory named Pansmeria, an adaptation and detailing of the Panspermia hypothesis, then went on to develop a model of how life emerged on Earth and how it may emerge similarly on other habitable planets of the universe where temperature is in the range to permit presence of liquid water, sunshine conducive for photosynthesis and gravity sufficient for holding an atmosphere. Some of the precise details of the theory may need slight revision but this blogger stands by the overall picture as originally presented. Every new evidence that has emerged from science since has supported it.
Now new evidence from the Rosetta mission support the founding principle of the hypothesis of eight years ago, that comets can bring life to Earth. See this report from CNN,
To quote from this report,
The European Space Agency (ESA), which is leading a consortium that includes NASA, announced that the mission to explore Comet 67P has discovered 16 organic compounds, described as "carbon and nitrogen-rich."The agency says on its website that the discovery, made by the Philae lander includes four compounds that have never before been detected in comets.And it adds that some of the compounds "play a key role in the prebiotic synthesis of amino acids, sugars ... the ingredients for life.""For example, formaldehyde is implicated in the formation of ribose, which, ultimately features in molecules like DNA. "The existence of such complex molecules in a comet, a relic of the early Solar System, imply that chemical processes at work during that time could have played a key role in fostering the formation of prebiotic material," it says.
However it seems that the scientists are still off key on the precise mechanisms as evident from the following comment in the same report,
Commenting on the findings, lander system engineer Laurence O'Rourke told CNN it was an important discovery. "If you apply energy to such organic compounds ... like a comet hitting a planet ... it could lead to the creation of amino acids which make up proteins, which are the basis of life itself," he said.
The more precise mechanisms are explained in this blog in the indicated early posts that can all be found at the following archive link:http://alienaccount.blogspot.in/2006_09_01_archive.html.
Just take care that the posts are presented in reverse chronological order on this page.
Image developed from a NASA image at: