Investigation of the Atmospheric Compositions using Lunar Eclipse Spectrum

Abstract

A lunar eclipse provides a unique opportunity to investigate the composition of Earth's atmosphere using spectroscopic techniques. In this study, the atmospheric constituents of Earth during a lunar eclipse are analyzed through spectroscopic observations. The data used in this research were obtained from observations of the lunar eclipse on July 16, 2019, using a 10-inch Sky-Watcher reflecting telescope equipped with suitable spectroscopic instruments. During a lunar eclipse, sunlight passes through different layers of Earth's atmosphere, undergoes refraction at the atmospheric limb, and then reaches the lunar surface, carrying valuable information about the chemical composition of the atmosphere. Spectra recorded from the Moon before the onset of the lunar eclipse and during the eclipse were analyzed and compared using the Origin software. The spectral analysis reveals distinct absorption features corresponding to major and biologically significant atmospheric gases, including oxygen, water vapor, and ozone. A comparison of the spectra indicates noticeable variations in the absorption strength of these gases during the lunar eclipse relative to normal lunar observations, which can be attributed to the increased optical path length of sunlight through Earth's atmosphere. The results of this study demonstrate that lunar eclipse spectroscopy is an effective method for detecting and characterizing biosignature gases in Earth's atmosphere. Moreover, this technique serves as a natural analog for transmission spectroscopy of exoplanetary atmospheres and can be used as a valuable model for identifying potential biosignature gases and assessing the habitability of terrestrial exoplanets.