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| Titel |
A multi-site ground-based search for Venus' lightning flashes |
| VerfasserIn |
Antonio García Muñoz, Enric Pallé, Pilar Montañés Rodríguez, Antonio Cabrera-Lavers, Felipe Murgas |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250058001
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| Zusammenfassung |
| The occurrence of lightning on Earth, Jupiter, Saturn, Uranus and Neptune is well accepted
[1]. Lightning on Venus seems to be more elusive, and its occurrence remains controversial
after a few decades of research. Past and current space missions have so far failed to report
lightning flashes on the planet. It is thought, however, that the combination of dense clouds
and vertical winds in Venus’ mesosphere provides suitable conditions for the formation of
intra-cloud lightning [2]. Lightning has played a key role in the fixation of N2 into
biologically available forms of nitrogen, a necessary step for the development of life on early
Earth [3]. Lightning is still relevant in the formation of NOx gas molecules in our planet’s
atmosphere. A clear-cut detection of lightning flashes on Venus would provide the
first evidence for lightning on a terrestrial planet other than our own. Following in
the steps of Hansell et al. [4], we have conducted narrowband fast imaging of the
Venus disk from an array of ground-based telescopes. Our search has focused on the
oxygen emission line at 777 nm that discharge and laser-excitation experiments have
suggested as the most prominent emission line in CO2/N2 gas mixtures subjected to
intense and quick deposition of energy. The dataset of already available observations
spans the November 2010–January 2011 period and involves two sites (Calar Alto
and Observatorio del Teide), and three instruments (AstraLux, FastCam and Wide
FastCam) originally conceived for lucky imaging of astrophysical targets. Further
observations with the 10.4-m Gran Telescopio Canarias from the Observatorio del Roque
de los Muchachos (La Palma) are scheduled for early March. In the talk, we will
summarize the analysis of the data and the conclusions drawn from this multi-site
campaign.
Refs.: [1] Zarka et al., SSR, doi:10.1007/s11214-008-9366-8, 2008; [2] Takahashi et al.,
SSR, doi: 10.1007/s11214-008-9400-x, 2008; [3] Navarro-González et al., Nature, 412, 2001;
[4] Hansell et al., Icarus, 117, 1995. |
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