As much as most space enthusiasts are reluctant to do so, it may be time for us to look not to the extrasolar planets, not to dwarf planets, not to black holes or quasar punches or solar storms–but to comets. Comet 67P, specifically, which the European Space Agency’s Philae lander has been investigating since November of last year, has just identified compounds that are also the necessary building blocks of life.
A SIGNIFICANT FIND ON COMET 67P
This was thought to be the case for quite some time, as there was simply no other way to explain how life on Earth got started. For years, scientists have thought that comets acted as seeds to an early Earth, bringing in basic materials with which Earth was later able to furnish life, and a thriving ecosystem.
HOLES IN THE THEORY
However, precisely how life originated on Earth is a mystery still annoying scientists to this day. So far, the general consensus is that we understand the few essential ingredients involved. Water and a few chemical building blocks had to be present, but they certainly weren’t always. Perhaps these things were delivered to the Earth over three billion years ago.
HOW DO COMETS GET HERE?
Most comets persist in places like the Kuiper Belt, far beyond the reach of most studying probes (save, perhaps for New Horizons), but every once in a while, a stray comet is moved out of its wide orbit. Comets’ trademark tails are formed by the increased heat they experience as they approach the sun, as has been observed for several centuries. The cool thing this tells us about comets today is that they carry large quantities of water.
But before the European Space Agency’s Rosetta spacecraft left for comet 67p in 2004, no one really knew if there was anything in the realm of necessary building blocks in comets. Was it just water and rocks?
BUILDING BLOCKS OF LIFE ON COMET 67P
The answer is a resounding yes. Published in the journal Science, Philae found 16 organic compounds, and four of them–methyl isocyanate, acetone, propionaldehyde, and acetamide–were not known to even exist on comets. Of more interesting note, it also found benzene, which is a cyclic hydrocarbon, and plenty of C02.
