[ExI] We are stardust, we are golden......

[BillK]

Not only are we literally made of stardust, but before the stardust
the precursors were created by starlight.

<http://www.jpl.nasa.gov/news/news.php?feature=6645>

Quote:
News | October 12, 2016
Building Blocks of Life's Building Blocks Come From Starlight


In the early 1940s, CH and CH+ were two of the first three molecules
ever discovered in interstellar space. In examining molecular clouds
-- assemblies of gas and dust -- in Orion with Herschel, scientists
were surprised to find that CH+ is emitting rather than absorbing
light, meaning it is warmer than the background gas. The CH+ molecule
needs a lot of energy to form and is extremely reactive, so it gets
destroyed when it interacts with the background hydrogen in the cloud.
Its warm temperature and high abundance are therefore quite
mysterious.

Why, then, is there so much CH+ in molecular clouds such as the Orion Nebula?

When ultraviolet light from large stars heats up the surrounding
hydrogen molecules, this creates prime conditions for forming
hydrocarbons. As the interstellar hydrogen gets warmer, carbon ions
that originally formed in stars begin to react with the molecular
hydrogen, creating CH+. Eventually the CH+ captures an electron to
form the neutral CH molecule.

"This is the initiation of the whole carbon chemistry," said John
Pearson, researcher at NASA's Jet Propulsion Laboratory, Pasadena,
California, and study co-author. "If you want to form anything more
complicated, it goes through that pathway."

Scientists combined Herschel data with models of molecular formation
and found that ultraviolet light is the best explanation for how
hydrocarbons form in the Orion Nebula.
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BillK