Powered by Indico
Where the molecules, from which life emerged on Earth, were made? There are at least nine places where these organics could be made: (1) at the boundaries of dense atmospheric layers due to interaction of charged particles with UV light; (2) in the Earth’s primordial planetary atmosphere due to lightning strikes; (3) in small pools of water at the foothills of volcanoes; (4) in volcanic plumes; (5) on seashores, during the ebb and flow of tides; (6) in the hydrothermal vents on ancient sea floors; (8) on the Earth surface via bombarding impactors (meteorites, comets and asteroids); and (9) in the dark molecular clouds (DMCs) such as the Horse Head Nebula. By far the largest mix of organic molecules would have been made within the DMCs. The pressure in these clouds is exceptionally low (e.g.,10-13 mbars) and temperatures range from 10 K to 50 K. These DMCs are considered to be akin to huge chemical factories.
The organics from DMCs would have been delivered on to Earth around 4.3 to 4.0 Gyrs ago. It is the opinion of the author that it highly probable that 95% to 99% of the organics, necessary for the emergence of life on the Earth, would have been the result of early planetary astrochemistry. The organics within the DMCs can be detected in the IR, since the majority of the molecules vibrate when radiation impinges upon organic molecules from a nearby star (or from a protosun), e.g., CO2 vibrates at the following wave-numbers: 660, 2347, 3602 and 3708 cm-1. The results of radio-telescopic survey can be compared with those obtained under simulated space condition experiments—e.g., electron irradiation of CO2 ice under low pressure (10-8 mbars) and low temperature (30 K). Pre-irradiation results of the CO2 yield vibrational peaks as mentioned above, which can be measured via FTIR spectroscopy. This methodology will be detailed in this talk. I will also outline the formation and identification of organic molecules pertaining to the emergence of life’s chemistry.