Saturday, 3 April 2010
Did a comet crash create life?
Hale-Bopp in 1997. Image courtesy of Philipp Salzgeber, Wikipedia.
The origin of life is still a great mystery for those who rule out the supernatural. No naturalistic hypothesis has ever solved the problem. There has been no shortage of attempts, however. Theoreticians have suggested almost everything watery from Charles Darwin’s warm little pond to meteorites and hydrothermal vents – all without result.
The problem is that life only comes from life.
Recently, Nir Goldman and colleagues developed a comet hypothesis at the Lawrence Livermore National Laboratory. The researchers used computer simulation to examine what happens to an ice grain in a comet when it hits a planet at a ”suitable” angle. They were able to make the grain become smaller and produce some chemical bonds.
It’s still a long way to amino acids that all have to be left handed, otherwise life cannot form.
Problem #1: Left-handed amino acids are not formed by accident. Miller and Urey’s origin of life experiment (1953), for instance, formed a mixture of right-handed and left-handed amino acids.
Problem # 2: Oxygen prevents the birth of life.
Problem # 3: Without oxygen there would be no ozone to protect life from the sun’s ultraviolet radiation.
Thus, with or without oxygen, a naturalistic origin of life appears to be impossible.
Sanderson, Katharine. 2010. Comet crash creates potential for life. Nature News (26 March)