Biosignatures & Paleobiology

Exploring and Detecting Metal Lines in Earth's Upper Atmosphere

By Keith Cowing
September 3, 2013
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Exploring and Detecting Metal Lines in Earth's Upper Atmosphere

Observations of the Earth as a planet using the earthshine technique (i.e. looking at the light reflected from the darkside of the Moon), have been used for climate and astrobiology studies.

They provide information about the planetary albedo, a fundamental parameter of the Earth’s energy balance. Here we present for the first time, observations of the earthshine taken at high spectral resolution. The high spectral resolution was chosen in order to investigate the possibility of detecting metallic layers in the Earth’s atmosphere of geological or meteoritic origin.

The SARG echelle spectrograph at the Telescopio Nazionale Galileo in La Palma was used to acquire the earthshine data. Observations were carried out on several nights in February 2011, with the spectral resolution set at 29,000, covering a spectral range from the near-ultraviolet (360 nm) to near-infrared (1011.9 nm).

While we find evidence for the detection of a Na layer in the earthshine, other atomic species are not detected, perhaps due to the low signal-to-noise ratio of the observations and the difficult telluric corrections. The Na layer is found to vary between observation dates, which we speculate is due to physical variations in mesospheric Na concentrations.

Earthshine observations at high spectral resolution: Exploring and detecting metal lines in the Earth’s upper atmosphere

B. Gonzalez-Merino, E. Palle, F. Motalebi, P. Montanes-Rodriguez, M. Kissler-Patig (Submitted on 2 Sep 2013)

Comments: 7 pages, 8 figures, 2 tables. Accepted for for publication in MNRAS

Subjects: Space Physics (; Earth and Planetary Astrophysics (astro-ph.EP)

DOI: 10.1093/mnras/stt1463

Cite as: arXiv:1309.0354 []

(or arXiv:1309.0354v1 [] for this version) Submission history From: Beatriz Gonzalez-Merino [view email] [v1] Mon, 2 Sep 2013 10:23:40 GMT (1283kb)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) πŸ––πŸ»