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.
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.
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.
Håkan Svedhem | EurekAlert!
Moon's crust underwent resurfacing after forming from magma ocean
22.11.2017 | University of Texas at Austin
NASA's James Webb Space Telescope completes final cryogenic testing
21.11.2017 | NASA/Goddard Space Flight Center
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
22.11.2017 | Life Sciences
22.11.2017 | Life Sciences
22.11.2017 | Materials Sciences