Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Venus Express’ infrared camera goes filming

08.05.2007
An exciting new series of videos from ESA’s Venus Express has been capturing atmospheric details of day and night areas simultaneously, at different altitudes.

The south pole of the planet and its gigantic double vortex has been pictured as never before.

The south pole of Venus and the double-eyed storm permanently rule atmospheric phenomena in that area of the planet. They are key to understanding the global atmospheric dynamics on Venus and will contribute to a better comprehension of the global meteorology of the planet.

In the search for all possible clues on how to solve the global atmospheric ‘puzzle’, the team of scientists behind the Ultraviolet, Visible and Near-Infrared Mapping Spectrometer (VIRTIS) on board Venus Express, have tried something new – starting from the south pole.

They started by focusing on this target from the advantageous position of the orbit apocentre (the furthest distance of the spacecraft from the planet). This allows the instrument to keep the target in the field of view for longer than in other portions of the orbit, where the spacecraft travels faster. In this favourable position, scientists made efficient use of the multi-wavelength capability of VIRTIS.

By using wavelengths longer than 3 microns in the thermal infrared range, VIRTIS can obtain a combined view of the day and night sides simultaneously. This is more convenient since at shorter wavelengths, the difference between the thermal radiation emitted on the day and night sides is too high to observe both regions simultaneously without ‘blinding’ some channels of the camera.

“It is comparable to looking at bright, sun-illuminated snow and at a dark sky without having to change your glasses,” said Giuseppe Piccioni, VIRTIS co-Principal Investigator. “In addition, within this observation process, not only can we look at the dark and lit sides of the south pole at the same time, but we can also look into the atmosphere at different depths. What we are building is the most complete 3D data set of the Venusian atmosphere to date.”

The VIRTIS videos of the south polar vortex presented here are the result of combined observations at two different wavelengths (3.8 and 1.7 microns, respectively) used at the same time. The various images were taken over five orbits, during a time-span of about 8 hours per orbit.

The 3.8-micron channel was chosen because of its compatibility (in exposure time) with the 1.7-micron observations, as well as for its capability to provide information about the cloud deck at about 65 kilometres altitude over the planet. The 1.7-micron wavelength was chosen to probe the atmosphere below the clouds when looking at the night side.

It is clearly possible to see that the morphology of the vortex changes a lot during the 8-hour observation session and from one orbit to the next (one Venus Express orbit is 24 hours long).

It is interesting to note that due to ‘bad weather conditions’, by the time of the observations, the videos do not show the maximum achievable image contrast. In fact, the visibility of the polar structure was somewhat reduced by the local increase of the upper atmospheric haze.

“If the weather permits, by extending the time span of our future observations, we may have the chance to obtain even clearer and more detailed views of the polar vortex,” added Piccioni.

“With video sequences of this kind, combining all the pieces of information together, we can study the dynamics and the evolution of the vortex both in the short and the long term,” said Pierre Drossart, the other co-Principal Investigator on VIRTIS. “What we want to understand is the overall 3D thermal structure of the vortex, especially the vertical variation of the horizontal winds.”

The next step will be the correlation of this data and data collected in the next sessions, with fluid dynamics computer models. This will eventually help the scientists create the best possible atmospheric model of Venus to date.

Håkan Svedhem | alfa
Further information:
http://www.esa.int/SPECIALS/Venus_Express/SEMQKVU681F_0.html

More articles from Physics and Astronomy:

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

nachricht Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication
16.07.2018 | Chinese Academy of Sciences Headquarters

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>