Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Venus Express reboots the search for active volcanoes on Venus

08.04.2008
ESA’s Venus Express has measured a highly variable quantity of the volcanic gas sulphur dioxide in the atmosphere of Venus. Scientists must now decide whether this is evidence for active volcanoes on Venus, or linked to a hitherto unknown mechanism affecting the upper atmosphere.

The search for volcanoes is a long-running thread in the exploration of Venus. “Volcanoes are a key part of a climate system,” says Fred Taylor, a Venus Express Interdisciplinary Scientist from Oxford University. That’s because they release gases such as sulphur dioxide into the planet’s atmosphere.

On Earth, sulphur compounds do not stay in the atmosphere for long. Instead, they react with the surface of the planet. The same is thought to be true at Venus, although the reactions are much slower, with a time scale of 20 million years.

Some scientists have argued that the large proportion of sulphur dioxide found by previous space missions at Venus is the ‘smoking gun’ of recent volcanic eruptions. However, others maintain that the eruptions could have happened around 10 million years ago and that the sulphur dioxide remains in the atmosphere because it takes such a long time to react with the surface rocks.

“I am very sceptical about the volcanic hypothesis. However, I must admit that we don't understand yet why there is so much sulphur dioxide at high altitudes”

New observations from Venus Express showing rapid variations of sulphur dioxide in the upper atmosphere have revived this debate.

The SPICAV (Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus) instrument analyses the way starlight or sunlight is absorbed by Venus’s atmosphere. The absorbed light tells scientists the identity of the atoms and molecules found in the planet’s atmosphere. This technique works only in the more tenuous upper atmosphere, above the clouds at an altitude of 70–90 km. In the space of a few days, the quantity of sulphur dioxide in the upper atmosphere dropped by two-thirds.

Jean-Loup Bertaux, Service d’Aeronomie du CNRS, Verrières-le-Buisson, is the Principal Investigator for SPICAV. “I am very sceptical about the volcanic hypothesis,” he says. “However, I must admit that we don’t understand yet why there is so much sulphur dioxide at high altitudes, where it should be destroyed rapidly by solar light, and why it is varying so wildly.”

Another instrument on Venus Express, VIRTIS (Visible and Infrared Thermal Imaging Spectrometer), can see below the clouds at infrared wavelengths. It detects the signature of sulphur dioxide by the amount of infrared radiation that the molecule absorbs, the stronger the signature, the more abundant the molecule.

Artist's impression of Venus Express
The variation appears to be smaller in the lower atmosphere. ”With VIRTIS, we monitor sulphur dioxide at an altitude of 35–40 km, and we have seen no change larger than 40% on a global scale over the last two years,” says Giuseppe Piccioni, VIRTIS co-Principal Investigator, IASF-INAF in Rome.

The only way to be absolutely certain that active volcanism is taking place on Venus is to see a volcano in action. This is not easy when you are trying to look through 100 km of thick, cloudy atmosphere. But the Venus Express team are working on two ways of doing this. The first is to look for localised increases in sulphur dioxide that would indicate a large plume of the gas issuing from a volcano. The other way is to look for hot spots on the surface that can be shown to be fresh lava flows.

In both cases, the instrument to use is VIRTIS. “No thermal anomaly has been detected so far,” says Pierre Drossart, Observatoire de Paris, France, and co-Principal Investigator on VIRTIS. Nevertheless, the search continues and the team plan to announce their findings soon.


For more information:

Jean-Loup Bertaux, SPICAV Principal Investigator
Service d'Aeronomie du CNRS
Email : Jean-Loup.Bertaux @ aerov.jussieu.fr
Giuseppe Piccioni, VIRTIS co-Principal Investigator
IASF-INAF, Rome, Italy
Email: Giuseppe.Piccioni @ iasf-roma.inaf.it
Pierre Drossart, VIRTIS co-Principal Investigator
Observatoire de Paris, France
Email: Pierre.Drossart @ obspm.fr
Håkan Svedhem, ESA Venus Express Project Scientist
Email : Hakan.Svedhem @ esa.int

Håkan Svedhem | EurekAlert!
Further information:
http://www.esa.int/SPECIALS/Venus_Express/SEMUNV5QGEF_0.html

More articles from Physics and Astronomy:

nachricht Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State

nachricht What do Netflix, Google and planetary systems have in common?
02.12.2016 | University of Toronto

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>