Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The puzzling 'eye of a hurricane' on Venus

14.03.2008
Venus Express has constantly been observing the south pole of Venus and has found it to be surprisingly fickle. An enormous structure with a central part that looks like the eye of a hurricane, morphs and changes shape within a matter of days, leaving scientists puzzled.

The eye of the hurricane is at the centre of a 2000 km-wide vortex. It was discovered in 1974 by the Mariner 10 spacecraft. There is a similar structure on the planet’s north pole, which was observed by the Pioneer Venus mission in 1979. Venus Express scientists have been studying the structure in the thermal infrared, the wavelength range which reveals the temperature at the cloud-tops. Seen in this wavelength, the core of the vortex appears very bright, probably indicating that a lot of atmospheric gases are moving downward in the region, which creates a depression at the cloud-tops, making the region hotter.


This image, of the ‘eye of the hurricane’ on Venus was taken by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on board Venus Express. This picture shows a region in the venusian atmosphere about 60 km from the surface, at a wavelength of about 5 micrometres. In this figure, the dipole assumes an eye-like shape and from here and the following images, it is possible to see how its shape rapidly evolves in a span of only 24 hours. The yellow dot in the image indicates the location of the south pole. Credits: ESA/VIRTIS/INAF-IASF/Obs. de Paris-LESIA/Univ. of Oxford

“Simply put, the enormous vortex is similar to what you might see in your bathtub once you have pulled out the plug” says Giuseppe Piccioni, co-Principal Investigator for the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on Venus Express, at IASF-INAF, Rome, Italy.

The fickle puzzle

In June 2006, the vortex appeared hourglass-shaped, closely matching observations in the north polar region by Pioneer Venus. Now we know that it changes its shape within a matter of days, from orbit to orbit. The image taken on 26 February 2007 shows the 'classic' dipole shape at the centre of the vortex, similar to that which has been observed previously. But an image taken a mere 24 hours earlier shows the centre of the vortex to be almost circular, indicating that the shape of this feature can change very fast. At other times, it is typically oval.

The dynamic nature of the vortex can be seen clearly in the video. It shows that the vortex is very complex, with atmospheric gases flowing in different directions at different altitudes.

What creates the puzzle?

Scientists are not sure what actually creates the vortex. Colin Wilson, at the University of Oxford, says, “One explanation is that atmospheric gases heated by the Sun at the equator, rise and then move poleward. In the polar regions, they converge and sinks again. As the gases moves towards the poles, they are deflected sideways because of the planet’s rotation.”

The dynamic nature of this vortex is similar to behaviour observed in other vortices on Earth, including those observed at the centre of hurricanes.

Investigators will keep a close watch on the polar region and its variability, in order to gain a better understanding of how it works.

Håkan Svedhem | alfa
Further information:
http://www.esa.int/SPECIALS/Venus_Express/SEMIZFM5NDF_0.html

More articles from Physics and Astronomy:

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

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

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

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>