Astrochemistry: October 2018

We present new estimates of protosolar elemental abundances based on an improved combination of solar photospheric abundances and CI chondritic abundances. These new estimates indicate CI chondrites and solar abundances are consistent for 60 elements.

Until now, in the scientific community there has been the prevailing view that thermal processes associated exclusively with the combustion and high-temperature processing of organic raw materials such as oil, coal, wood, garbage, food, tobacco underpin the formation of PAHs

Extraterrestrial amino acids, the chemical building blocks of the biopolymers that comprise life as we know it on Earth are present in meteoritic samples.

In molecular clouds at temperatures as low as 10 K, all species except hydrogen and helium should be locked in the heterogeneous ice on dust grain surfaces. Nevertheless, astronomical observations have detected over 150 different species in the gas phase in these clouds.

The relative abundance of deuterium and hydrogen is a potent tracer of planet formation and evolution. Jupiter and Saturn have protosolar D/H ratios, a relic of substantial gas accretion from the nebula, while Neptune and Uranus are enhanced in D by accretion of ices into their envelopes. For terrestrial planets, D/H ratios are used to determine the mechanisms of volatile delivery and subsequent atmosphere loss over the lifetime of the planet.

All living beings need cells and energy to replicate. Without these fundamental building blocks, living organisms on Earth would not be able to reproduce and would simply not exist.