Using the spacecraft’s ultraviolet and infrared cameras, the Venus Express team, including UK scientists, have been able to compare what the planet looks like at different wavelengths, allowing them to study the physical conditions and dynamics of the planet’s atmosphere. These results appear today (4th December) in the journal Nature.
Professor Fred Taylor, one of the Venus Express scientists, from Oxford University and funded by the UK’s Science and Technology Facilities Council, said, "The features seen on Venus in ultraviolet light have been a puzzle to astronomers for nearly a century. These new images have revealed the structure in the clouds that produces them and shows how they result from complex meteorological behaviour. We can now study in much greater detail and try to understand the origin of features such as the large hurricane-like vortex over the north and south poles. Like many things on Venus, including global warming, this feature has similarities to atmospheric and environmental process on Earth, but the Venus version is much more extreme.”
Observations made with the ultraviolet camera show numerous high-contrast features. The cause is the uneven distribution of a mysterious chemical in the atmosphere that absorbs ultraviolet light, creating bright and dark zones. But the exact chemical species that creates the high-contrast zones still remains elusive. Most simple candidates have been ruled out, and a complex compound of sulphur is now the favourite. It will probably take measurements inside the clouds to identify it, but we do know that Venus’ atmosphere is loaded with sulphur from volcanic eruptions on the surface below.
The ultraviolet images also reveal the structure of the clouds and the dynamical conditions in the atmosphere, whereas the infrared data provides information on the temperature and altitude of the cloud tops.
Professor Keith Mason, Chief Executive of the Science and Technology Facilities Council, said “These new images provide us with a wealth of information about the atmospheric conditions of this fascinating neighbour planet. We can now study Venus in greater detail to understand more about its complex processes. “
With data from Venus Express, scientists have learnt that the equatorial areas on Venus that appear dark in ultraviolet light are regions of relatively high temperature, where intense convection brings up the mysterious dark material from below. In contrast, the bright regions at mid-latitudes are areas where the temperature in the atmosphere decreases with depth, which prevents air from rising. The effect is most extreme in a wide belt around each pole, nicknamed the ‘cold collar’, which appears darkest, hence coldest, in infrared measurements, but as a bright band in the ultraviolet images.
Observations in the infrared have been used to map the altitude of the cloud tops. Surprisingly, the clouds in both the dark tropics and the bright mid-latitudes are located at about the same height of about 72 km above the surface. At 60 degrees of latitude, the cloud tops start to sink, reaching a minimum of about 64 km at the ‘eye’ of a huge hurricane-like vortex at the pole, which measures about 2000 km across and rotates around the pole in about 2.5 days.
Further Improvement of Qubit Lifetime for Quantum Computers
09.12.2016 | Forschungszentrum Jülich
Electron highway inside crystal
09.12.2016 | Julius-Maximilians-Universität Würzburg
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
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...
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...
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