Ozone: Twilit Skies, and (Exo-)planet Transits
Abstract
Although only a trace constituent gas in the Earth's atmosphere, ozone plays a critical role in protecting the Earth's surface from receiving a damaging flux of solar ultraviolet radiation. What is not generally appreciated, however, is that the intrinsically weak, visible Chappuis absorption band becomes an important influence on the colour of the entire sky when the Sun is low or just below the horizon. This effect has been explored using spectra of the sunset and also of the eclipsed Moon; phenomena that involve a similar passage of sunlight tangential to the Earth's surface. This geometry will also be relevant in future attempts to perform transit spectroscopy of exo-Earths.
- Publication:
-
The Messenger
- Pub Date:
- March 2011
- Bibcode:
- 2011Msngr.143...27F