Mid-Infrared Properties of Disk Averaged Observations of Earth with AIRS

TL;DR

This study analyzes Earth's mid-infrared spectra from AIRS to identify seasonal and rotational variations, providing insights into potential observations of extrasolar terrestrial planets by future telescopes.

Contribution

It presents the first high-resolution, seasonally spanning mid-infrared spectra of Earth, exploring how cloud cover and viewing angles affect observable signatures.

Findings

Detected seasonal spectral variations due to cloud cover and viewing geometry.

Identified spectral features that could be observable in future exoplanet studies.

Provided a baseline for interpreting mid-infrared observations of Earth-like exoplanets.

Abstract

We have investigated mid-infrared spectra of Earth obtained by the Atmospheric Infrared Sounder (AIRS) instrument on-board the AQUA spacecraft to explore the characteristics that may someday be observed in extrasolar terrestrial planets. We have used the AIRS infrared (R ~ 1200; 3.75-15.4 microns) spectra to construct directly-observed high-resolution spectra of the only known life bearing planet, Earth. The AIRS spectra are the first such spectra that span the seasons. We investigate the rotational and seasonal spectral variations that would arise due to varying cloud amount and viewing geometry and we explore what signatures may be observable in the mid-infrared by the next generation of telescopes capable of observing extrasolar terrestrial planets.