Details

Autor(en) / Beteiligte

• Griessmeier, J-M
• Tabataba-Vakili, F
• Stadelmann, A
• Grenfell, J L
• Atri, D

Titel

Galactic cosmic rays on extrasolar Earth-like planets: II. Atmospheric implications

Ist Teil von

• Astronomy and astrophysics (Berlin), 2016-03, Vol.587, p.A159

Ort / Verlag

EDP Sciences

Erscheinungsjahr

2016

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Theoretical arguments indicate that close-in terrestial exoplanets may have weak magnetic fields. As described in the companion article (Paper I), a weak magnetic field results in a high flux of galactic cosmic rays to the top of the planetary atmosphere. We investigate effects that may result from a high flux of galactic cosmic rays both throughout the atmosphere and at the planetary surface. Using an air shower approach, we calculate how the atmospheric chemistry and temperature change under the influence of galactic cosmic rays for Earth-like (N2-O2 dominated) atmospheres. We evaluate the production and destruction rate of atmospheric biosignature molecules. We derive planetary emission and transmission spectra to study the influence of galactic cosmic rays on biosignature detectability. We then calculate the resulting surface UV flux, the surface particle flux, and the associated equivalent biological dose rates. For a planet with an Earth-like atmospheric pressure, weak or absent magnetospheric shielding against galactic cosmic rays has little effect on the planet.