New method can help gauge atmospheric pressure of exoplanets

Researchers have developed a new method of gauging the atmospheric pressure of exoplanets, or worlds beyond the solar system, by looking for a certain type of molecule.

Washington: Researchers including an Indian-origin researcher have developed a new method of gauging the atmospheric pressure of exoplanets, or worlds beyond the solar system, by looking for a certain type of molecule.

The method, devised by Amit Misra, a UW astronomy doctoral student, and co-authors, involves computer simulations of the chemistry of Earth`s own atmosphere that isolate what are called "dimer molecules" - pairs of molecules that tend to form at high pressures and densities in a planet`s atmosphere. There are many types of dimer molecules but this research focused only on those of oxygen. The researchers ran simulations testing the spectrum of light in various wavelengths. Dimer molecules absorb light in a distinctive pattern, and the rate at which they form is sensitive to the pressure, or density, in the planet`s atmosphere. Mishra said that the idea is that if they are able to do this for another planet, they could look for this characteristic pattern of absorption from dimer molecules to identify them. The presence of such molecules, he said, likely means the planet has at least one-quarter to one-third the pressure of Earth`s atmosphere. The study has been published in the journal Astrobiology.