Way to detect tiny particles in exoplanet atmospheres found

A new study has found the method of identifying and measuring particles that are 10 times smaller than the width of a human hair, in exoplanet atmospheres.

Researcher Adrian Brown said that the effect was related to a familiar phenomenon known as Rayleigh scattering that makes the sky blue, in which a blue tint is observed in the light from far-off objects caused by the way in which small particles, no more than a micron in size (one-thousandth of a millimeter) scatter light.

By analyzing spectroscopic data from the Cassini orbiter, the Mars Reconnaissance Orbiter, and ground-based telescopes, Brown managed to document this blue enhancement in many nearby objects, including the rings of Saturn, its moons Dione and Epimetheus, Mars, the Moon, and the tail of Comet 17P/Holmes.

Brown's theoretical study of the phenomenon showed that the spectral bluing occurred any time sufficiently small objects were in the field of view and in his studies, he considered particles between 0.1 and 1.0 microns in size; a human hair is roughly 17 microns in diameter.

Brown stated that this technique would allow them to find extremely tiny particles in the atmospheres or on the surfaces of exoplanets that were tens or thousands of light-years away.

The research is published in Icarus.