In “Building blocks for life on Earth may have had dusty start” (MSNBC.com, March 29, 2012), Clara Moskowitz reports,
Geophysicist Fred Ciesla and astrobiologist Scott Sandford showed in their computer model how the orbiting dust that provided the raw material for planets, asteroids and comets could have been exposed to the ultraviolet light needed to develop organic molecules.
“The origin of these organics has been a mystery,” Ciesla told SPACE.com. “There have been a number of places where they have been thought to have formed, and none are mutually exclusive.”
Still, the fact that organics could have formed in the disk doesn’t explain exactly how they got onto Earth. When Earth formed, it would have been a molten mess, with temperatures high enough to destroy any organics present at the time.
However, scientists say organic compounds could have survived on the asteroids and comets left behind in the solar system after the planets formed. As these bodies pummeled the Earth over the eons, they could have deposited the building blocks for life.
It’s all these “could haves” and “would haves” that are the fundamental problem for origin of life studies.