. 24/7 Space News .
The Restless Atmosphere Of Venus

Previous observations had hinted that the convection cells might be as large as 200 km across, but this was difficult to explain using conventional atmospheric physics. Venus Express observations clearly show that the cells are much smaller, about 20-30 km. At this size, the cells are probably confined to the mid-atmosphere, leaving a stable atmospheric layer below.
by Staff Writers
Paris, France (ESA) Dec 05, 2007
Venus Express has studied the true extent of Venus's restless atmosphere. This includes the planet's glow, its highly variable south polar vortex and the dynamic upper atmosphere, different from what is seen on any other rocky planet of the Solar System. Venus' faint glow of light coming from molecules in the atmosphere is providing scientists a detailed look into its physical and chemical processes.

The first triumph for Venus Express was to uncover the planet's dramatic south polar vortex in unprecedented, fine detail. The vortex powerfully drives the cloud dynamics at all altitudes. "It plays an important role in balancing the atmosphere," says Giuseppe Piccioni, VIRTIS co-Principal Investigator at IASF-Istituto Nazionale di Astrofisica, Italy, who used the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument on Venus Express to discover and study the structure.

Planetary scientists believe that the double hurricane-like feature is formed when warm air from the equatorial regions of Venus rises into the atmosphere and travels down towards the pole of the planet. Once there, it begins to cool and sink, spiralling down to create the vortex.

Venus Express has also revealed new details about the turbulent region known as the 'sub-solar' region. This is the part of the planet that faces the Sun, which changes slowly as Venus rotates. It is the area of Venus that absorbs most of the incoming heat from the Sun, making it a crucial location for the atmospheric dynamics.

As the heat streams into the atmosphere, the gas breaks up into rolling pockets known as convection cells. "It is as if the whole region is boiling," says Wojtech Markiewicz, VMC Principal Investigator at the Max-Planck-Institute for Solar System Research, Germany, drawing an analogy to the way milk boils in a pan.

Previous observations had hinted that the convection cells might be as large as 200 km across, but this was difficult to explain using conventional atmospheric physics. Venus Express observations clearly show that the cells are much smaller, about 20-30 km. At this size, the cells are probably confined to the mid-atmosphere, leaving a stable atmospheric layer below.

Venus has a high-altitude haze layer composed of brightly reflecting aerosol particles and a new mystery has been revealed. On 13 January 2007, under the gaze of Venus Express's instruments, two thirds of the planet's southern hemisphere suddenly brightened as something triggered the aerosols to form at a furious rate. As yet, no one knows what started this amazing transformation. The feature disappeared just as quickly a few days later when the aerosols had coagulated and the haze had cleared up.

Venus Express has also seen the glow from molecules of oxygen and carbon dioxide in the atmosphere of the planet. In the case of carbon dioxide, the 'airglow' is produced when the molecule absorbs and then re-emits a photon from the Sun. This happens quite quickly and the glow from carbon dioxide is confined to the day-side and low-pressure altitudes of the planet.

In contrast, the faint glow from oxygen has been detected from night side of the planet. This indicates a different mechanism at play. Indeed, the oxygen glows when two stray oxygen atoms join together, releasing some energy. Both types of emission tell scientists about the conditions in the atmosphere.

"The airglow allows us to constrain models of the atmosphere," says Pierre Drossart, Observatoire de Paris, France, and the VIRTIS co-Principal Investigator. Already, the Venus Express results have allowed planetary scientists to adjust the temperatures in the atmosphere in their computer models to more realistic values.

Most importantly, Venus Express is monitoring changes in the airglow that occur across the planet and at different times. This is providing planetary scientists with an unprecedented level of detail and, as Drossart says, "Science is made of the details."

Venus Express is certainly providing them.

Community
Email This Article
Comment On This Article

Related Links
Venus Express
Venus Express News and Venusian Science



Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News


The Venusian Climate And Its Evolution
Paris, France (ESA) Dec 04, 2007
Today, Venus is a hellish place of high temperatures and crushing air pressure. Venus Express is showing that this was not always the case. Instead, some time in the past, Venus was probably much more Earth-like and contained large quantities of water. Planetary scientists have long wondered just how Earth-like Venus is or might have been. Until the 1960s, astronomers speculated that Venus might be a tropical forest planet. This view changed when microwave observations began to suggest an extremely hot surface.







  • MU Engineers Develop Software Solution For Complex Space Missions
  • Star Talk
  • Computer predicts Voyager 2 milestone
  • Computer Simulation Predicts Voyager 2 Will Reach Major Milestone In Late 2007�Early 2008

  • Multi-Tasking Rover Supports Multiple Missions
  • Spirit Breaks Free In Race For Survival
  • Noctis Labyrinthus, Labyrinth Of The Night
  • Russia Conducts First Experiment In Preparation For Mars-500

  • Arianespace warns US over Chinese space 'dumping'
  • Sea Launch Reschedules The Thuraya-3 Launch Campaign
  • Sea Launch Reschedules The Thuraya-3 Launch Campaign
  • Russia To Launch Manned Spacecraft From New Site In 2018

  • Use Space Technology And IT For Rural Development
  • China, Brazil give Africa free satellite land images
  • Ministerial Summit On Global Earth Observation System Of Systems
  • NASA-Conceived Map Of Antarctica Lays Ground For New Discoveries

  • The PI's Perspective: Autumn 2007: Onward to the Kuiper Belt
  • Data For The Next Generations
  • Goddard Instrument Makes Cover Of Science
  • Checking Out New Horizons

  • UBC Astronomers Discover How White Dwarf Stars Get Their Kicks
  • Dark Matter In Newborn Universe Doused Earliest Stars
  • An X-Ray Santa Claus In Orion
  • Dark Energy -- 10 Years On

  • China Will Soon Have Its Own Moon Globe
  • Data From Chinese Lunar Orbiter Available To All
  • Northrop Grumman Starts Integration And Test On LCROSS Spacecraft
  • KAGUYA (SELENE) Composes 3-D Movies With Terrain Camera Images

  • EU rallies Spain to clinch unanimous Galileo deal
  • EU nations 'close' to political agreement on satnav project
  • The Hills And Valleys Of Earth's Largest Salt Flat
  • US plans GPS satellite navigation upgrade to rival EU

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement