Topic: Earth life 'may have come from Mars'

[Simon]

Life may have started on Mars before arriving on Earth, a major scientific conference has heard.

New research supports an idea that the Red Planet was a better place to kick-start biology billions of years ago than the early Earth was.

Details of the theory were outlined by Prof Steven Benner at the Goldschmidt Meeting in Florence, Italy.

Scientists have long wondered how atoms first came together to make up the three crucial molecular components of living organisms: RNA, DNA and proteins.

The molecules that combined to form genetic material are far more complex than the primordial "pre-biotic" soup of organic (carbon-based) chemicals thought to have existed on the Earth more than three billion years ago, and RNA (ribonucleic acid) is thought to have been the first of them to appear.

Simply adding energy such as heat or light to the more basic organic molecules in the "soup" does not generate RNA. Instead, it generates tar.

RNA needs to be coaxed into shape by "templating" atoms at the crystalline surfaces of minerals.

The minerals most effective at templating RNA would have dissolved in the oceans of the early Earth, but would have been more abundant on Mars, according to Prof Benner.

http://www.bbc.co.uk/news/science-environment-23872765

[Clive]

It's a very interesting scenario which we all want to believe but how many times have we been here before?  The famous Martian meteorite ALH84001 is a classic example of scientists claiming they had discovered microbial life on the planet in order to secure further funding for space probes to Mars.  It turned out that the "microbe" was  just inorganic material.