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Bringing the Building Blocks of Life Down to Earth

By David Reneke

Astronomers find more evidence for how life began in Earth, and send a greeting to a red dwarf with two habitable planets.

The full text of this article can be purchased from Informit.

Where did we come from and how did we get here? How life began on Earth, roughly four billion years ago, is the eternal question and the basis for almost all of cosmology. New results from scientists at McMaster University and the Max Planck Institute for Astronomy suggest a key role for meteorites landing in warm little ponds, delivering essential organic molecules that kick-started the emergence of life in the shape of self-replicating RNA molecules.

The astronomers reached their conclusions after assembling models about planet formation, geology, chemistry and biology into a coherent quantitative model for the emergence of life. Perhaps the most interesting result from these calculations is that life must have emerged fairly early while Earth was still taking shape, only a few hundred million years after the Earth had cooled sufficiently to allow liquid surface water such as ponds or oceans to form.

The building blocks of life would have been brought to Earth by meteorites during an era when Earth’s bombardment by such small extraterrestrial rocks was much more intense than today.

The new work supports the “warm little pond” hypotheses for the origin of life, with RNA polymers forming in shallow ponds during cycles in which the pond water evaporates and is refilled periodically. It shows how meteorites could have transported a sufficient number of...

The full text of this article can be purchased from Informit.