Subscribe free to our newsletters via your
. 24/7 Space News .

Hot Atmosphere Of Venus May Cool Planet's Interior
by Staff Writers
Rome, Italy (SPX) Sep 24, 2010

Maat Mons is displayed in this computer generated three-dimensional perspective of the surface of Venus. The viewpoint is located 634 kilometers (393 miles) north of Maat Mons at an elevation of 3 kilometers (2 miles) above the terrain. Lava flows extend for hundreds of kilometers across the fractured plains shown in the foreground, to the base of Maat Mons.

The view is to the south with the volcano Maat Mons appearing at the center of the image on the horizon and rising to almost 5 kilometers (3 miles) above the surrounding terrain. Maat Mons is located at approximately 0.9 degrees north latitude, 194.5 degrees east longitude with a peak that ascends to 8 kilometers (5 miles) above the mean surface. Maat Mons is named for an Egyptian Goddess of truth and justice. Magellan synthetic aperture radar data is combined with radar altimetry to develop a three-dimensional map of the surface. The vertical scale in this perspective has been exaggerated 10 times.

Rays cast in a computer intersect the surface to crate a three-dimensional perspective view. Simulated color and a digital elevation map developed by the U.S. Geological Survey are used to enhance small-scale structure. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft. The image was produced by the Solar System Visualization project and the Magellan Science team at the JPL Multimission Image Processing Laboratory and is a single frame from a video released at the April 22, 1992 news conference. Image Credit: NASA/JPL

The heat in the atmosphere of Venus, induced from a strong greenhouse warming, might actually have a cooling effect on the planet's interior. This counter-intuitive theory is based on calculations from a new model presented at the European Planetary Science Congress (EPSC) in Rome on Tuesday 21st September.

"For some decades we've known that the large amount of greenhouse gases in the atmosphere of Venus cause the extreme heat we observe presently," explains Lena Noack from the German Aerospace Center (DLR) in Berlin, lead author of the study.

"The carbon dioxide and other greenhouse gases that are responsible for the high temperatures were blown into the atmosphere by thousands of volcanoes in the past. The permanent heat - today we measure almost 470 degrees Celsius globally on Venus - might even have been much higher in the past and, in a runaway cycle, led to even more volcanism.

But at a certain point this process turned on its head - the high temperatures caused a partial mobilization of the Venusian crust, leading to an efficient cooling of the mantle, and the volcanism strongly decreased. This resulted in lower surface temperatures, rather comparable to today's temperature on Venus, and the mobilization of the surface stopped."

The source of the magma, or molten rocky material, and the volcanic gases lies deep in the mantle of Venus. The decay of radioactive elements, inherited from the building blocks of the Solar System's planets, and the heat stored in the interior from planet formation produce enough heat to generate partial melts of silicate-, iron- and magnesium-rich magma in the upper mantle.

Molten rock has more volume and is lighter than the surrounding solid rock of identical composition. The magma therefore can rise upwards and eventually penetrate through the rigid crust in volcanic vents, spreading lava over the surface and blowing gases into the atmosphere, mostly greenhouse gases like carbon dioxide (CO2), water vapor (H2O) and sulphur dioxide (SO2).

However, the more greenhouse gases, the hotter the atmosphere - possibly leading to even more volcanism. To find out if this runaway process would end in a red-hot Venus, Lena Noack and Doris Breuer, co-author of the study, calculated for the first time a model where the hot atmosphere is 'coupled' to a 3D model of the planet's interior.

Unlike here on Earth, the high temperatures have a much bigger effect at the interface with the rocky surface, heating it up to a large extent.

"Interestingly, due to the rising surface temperatures, the surface is mobilized and the insulating effect of the crust diminishes," says Noack. "The mantle of Venus loses much of its thermal energy to the outside.

It's a little bit like lifting the lid on the mantle: the interior of Venus suddenly cools very efficiently and the rate of volcanism ceases. Our model shows that after that 'hot' era of volcanism, the slow-down of volcanism leads to a strong decrease of the temperatures in the atmosphere."

The calculations of the geophysicists yield another interesting result: the process of volcanic resurfacing takes place at different places at different times. When the atmosphere cools, the mobilization of the surface stops.

However, there are still a few active volcanoes which resurface some spots with lava flows. Some volcanoes might be active even today, which fits recent results from the European Space Agency's Venus Express mission.

This detected 'hot spots', or unusual high surface temperatures at volcanoes previously thought to be extinct. So far no 'smoking gun', or active volcano has been identified on Venus - but it seems not unlikely that Venus Express or future space probes will detect the first active volcano on Earth's next neighbor.


Related Links
EPSC 2010
Venus Express News and Venusian Science

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

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

Japanese Spacecraft Approaches Venus
Huntsville AL (SPX) Aug 17, 2010
For the next few months, Venus will be softly resplendent in the evening sky, a treat for stargazers - but looks can be deceiving. Consider this: The Venusian surface is hot enough to melt lead. The planet's 96% carbon dioxide atmosphere is thick and steamy with a corrosive mist of sulfuric acid floating through it. The terrain is forbidding, strewn with craters and volcanic calderas - and bone ... read more

Magnetic Anomalies Shield The Moon

New Australian footage of Neil Armstrong's moon walk

Watch Out For The Super Harvest Moon

Water on Moon is bad news for China's lunar telescope

Martian Moon Phobos May Have Formed by Catastrophic Blast

First Results From Herschel Mars Observations

Peculiar Phenomena During Northern Spring On Mars

Opportunity Approaching Possible Meteorite

CSF Strongly Supports Senate NASA Authorization Bill

Be Careful What You Do With Space Garbage

ADI Advances US Legislative Campaign Against Planned NASA Primate Experiments

Virgin to launch space tourism in 18 months: Branson

China Ready For Another Lunar Encounter

China keeps up busy space launch schedule

Space-Age Device To Deliver More Efficient Health Care On Earth And Above

China Launches New Satellite

Soyuz crew admit to disappointment at delayed landing

Russian spacecraft lands safely after delays

International Partners Discuss ISS Extension And Use

Spacecraft with three cosmonauts undocks after delay

Vandenberg launches Minotaur IV

LockMart And ATK Athena Launch Vehicles Selected As A NASA Launch Services Provider

Sirius XM-5 Satellite Delivered To Baikonur For October Launch

Emerging Technologies May Fuel Revolutionary Launcher

This Planet Smells Funny

Scientists looking to spot alien oceans

Deadly Tides Mean Early Exit For Hot Jupiters

Can We Spot Volcanoes On Alien Worlds

Northrop Grumman Space Cryocoolers Achieve 100 Years Of On-Orbit Performance

NASA's NPP Climate Satellite Passes Pre-Environmental Review

Japan to pilot digital textbooks in classrooms

BlackBerry maker RIM unveils 'PlayBook' tablet computer

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. 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 Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement