For years, the prevailing theories about how life originated on Earth (and, perhaps, beyond) relied entirely on traumatic events, such as a lightning strike or a volcanic blast that created the first amino acids on the planet.
As Charles Darwin once observed:
The original spark of life may have begun in a warm little pond, with all sorts of ammonia and phosphoric salts, lights, heat, electricity, etc. present, so that a protein compound was chemically formed ready to undergo still more complex changes.
New discoveries using data out of the European Space Agency's Herschel Space Observatory now indicate that while that still might be the case, the basic building blocks of life's basic building blocks — in other words, the very molecules that built the amino acids which were sparked and sprouted life into life in the Miller-Urey experiment — come not from turbulent or violent events, but from steady ultraviolet light emitted by stars:
It has long been known that the Orion Nebula has a lot of hydrogen gas. 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."
The Orion Nebula is the closest region to Earth that forms massive stars, making it (relatively speaking) a well studied region:
According to modern astronomers, the Orion Nebula is an enormous cloud of gas and dust, one of many in our Milky Way galaxy. It lies roughly 1,300 light-years from Earth.
At some 30 to 40 light-years in diameter, this great big nebulous cocoon is giving birth to perhaps a thousand stars. A young open star cluster, whose stars were born at the same time from a portion of the nebula and are still loosely bound by gravity, can be seen within the nebula. It is sometimes called the Orion Nebula Star Cluster. In 2012, an international team of astronomers suggested this cluster in the Orion Nebula might have a black hole at its heart.
The Herschel project was the largest space-based telescope when it was launched in 2009 to observe radiation at far-infrared and sub-millimeter wavelengths. While it ran out of coolant in 2013, scientists are still mapping and analyzing the data that it gathered during the mission.
