American Institute of Physics | 2018 Apr 25
New research offers evidence that humans -- and the rest of life on earth -- may have been able to form with the right combination of star dust and radiation.
In a laboratory experiment that mimics astrophysical conditions, with cryogenic temperatures in an ultrahigh vacuum, scientists used an electron gun to irradiate thin sheets of ice covered in basic molecules of methane, ammonia and carbon dioxide. These simple molecules are ingredients for the building blocks of life. The experiment tested how the combination of electrons and basic matter leads to more complex biomolecule forms -- and perhaps eventually to life forms. ...
The right conditions, in space, include ionizing radiation. In space, molecules are exposed to UV rays and high-energy radiation including X-rays, gamma rays, stellar and solar wind particles and cosmic rays. They are also exposed to low-energy electrons, or LEEs, produced as a secondary product of the collision between radiation and matter. The authors examined LEEs for a more nuanced understanding of how complex molecules might form.
... the authors exposed multilayer ice composed of carbon dioxide, methane and ammonia to LEEs and then used a type of mass spectrometry called temperature programmed desorption (TPD) to characterize the molecules created by LEEs. ...
Glycine Formation in CO2:CH4:NH3 Ices Induced by 0-70 eV Electrons - Sasan Esmaili et al
- Journal of Chemical Physics 148(16):4702 (28 Apr 2018) DOI: 10.1063/1.5021596