Posted on 10/19/2007 8:50:29 AM PDT by Swordmaker
PARIS, 28 June 2006 - The European Space Agencys new mission to Venus has discovered that the planet has a bizarre double vortex which whirls in the atmosphere above its south pole, ESA said on Tuesday.
The double eye, formed by winds of super-hurricane force, was spotted by the unmanned Venus Express spacecraft in its very first swing around Venus, it said.
Previous missions to Venus have spotted a similar structure over its north pole and glimpsed at stormy atmospheric behaviour at the south pole.
The winds on Venus spin westwards at hundreds of kilometres per hour, taking only four days to complete the rotation of a planet that is just under the size of Earth.
This super-rotation, combined with the natural recycling of hot air in the atmosphere, would logically induce a vortex over each pole, but the mystery is why there should be two vortices.
We still know very little about the mechanisms by which the super-rotation and the polar vortexes are linked, said Hakan Svedhem, the missions project scientist.
Also, we are still not able to explain why the global atmospheric circulation of the planet results in a double vortex and not a single vortex... Atmospheric vortexes are very complex structures that are very different to model, even on Earth.
Venus Express is Europes first dedicated mission to Earths closest planet.
It went into orbit around Venus on April 11, equipped with scanners aimed at deciphering the enigmatic Venusian atmosphere.
The planet seems to be a case of runaway global warming, and understanding the mechanisms that drive this could be of use in combatting man-made climate change on Earth.
Venuss mean surface temperature is 457ËCelsius - hot enough to melt lead and even hotter than Mercury, the closest planet to the Sun. Its atmosphere is 96 per cent carbon dioxide, with roiling, yellowish clouds of sulphur and sulphuric acid droplets.
“The planet seems to be a case of runaway global warming, and understanding the mechanisms that drive this could be of use in combatting man-made climate change on Earth.”
Yeah. It was all those Venusians and their darned SUV’s that started it..
Science, a continuing learning curve.
If only the Venusians had used carbon offest credits.
Climate change is such a big issue over there.
Whoops. The article mentions this.
Green house effect cannot be the explanation for Venus' hot temperature... it is exothermic... giving off more heat that it receives from the Sun. Either there is another source of energy or the heat is a remnant of an even hotter past.
I doubt you have a clue about what you are talking about. But giving you the benefit of the doubt I should note that every planet emits more heat than it receives from the Sun. In the case of the rocky planets, radioactive decay of certain elements accounts for the energy difference, and for the gas and ice giants, their continuing compression accounts for the heat.
This does not mean that CO2 in the atmosphere can't explain the atmosphere. Only someone who doesn't know anything about planetary science or even basic thermodynamics would say that.
This does not mean that CO2 in the atmosphere can't explain the atmospheric temperature.
For years, planetary science held that the surface temperature of Venus would be only slightly hotter than the Earth... cool enough that liquid water would exist. But that prediction was blown out of the water by our actual space probe visits to Venus. Instead of "slightly hotter" they found a world with a surface temperature of about 450º Celsius (723 Kelvin), hot enough to keep lead and tin in a molten state.
What is your point? Are you trying to add credibility to the point that the CO2 in Venus' atmosphere is what has caused the temperature to be that high, contrary to your prior post? If so, good. I agree that the greenhouse effect on Venus is why the temperature of Venus' atmosphere is so high.
I assumed that was what you meant. ;^)>
But that does bring up another anomaly... explaining the atmosphere. The atmospheric pressure of Venus is about 90 times that of the Earth's, its supposed twin. How can this be? Why hasn't Venus' atmosphere sublimated into space over the eons? Its depth is a little greater than Earth's, extending to low Venus orbit (about 155 miles). Are heavier, denser gasses the explanation? Can the existence of our Moon and its tidal forces completely explain the difference? Planetary scientists have stated that Venus probably had an atmosphere similar in composition and density to Earth's in the distant past... yet today it is far different. Where did all the (97%) CO2 come from to increase the density and pressure?
Third anomaly... The surface of Venus more closely resembles the surface of the Moon than that of Earth. It is pockmarked with over 1000 of what are assumed to be meteor craters that we have mapped so far. These are postulated (read: pulled a figure out of their nose) to have occurred after 500 million years ago... when Venus' surface was "resurfaced," which is also a "fact" that is really not in evidence. (That "resurfacing" is an assumption based on the fact that they see no remnant craters that seem to be older than their assumed 500M year figure. . kind of circular reasoning, I think)
Yet Earth, Venus' supposed twin, is not. Venusian winds are measured at much higher velocities than those on Earth. Although surface winds are fairly moderate, they are very dense and carry erosive sand and stones. In addition, far more tornados are observed at much higher velocities than Earth's. Why, then are not the craters quickly eroded away. Is water which exists on Earth that much more erosive than an atmosphere of 90 Bars carrying erosive materials? How, indeed, do the meteors get through an atmosphere 90 times denser than Earth's without burning up due to a far higher amount of friction? Why are there so many craters larger than 3km in diameter (up to 285km) and why doesn't Earth, which also received a similar bombardment, retain more pristine craters? Even the Moon's craters are more eroded than are Venus' (they assume by micro-meteors).
The number of large craters ( greater than 50km) on Mars seems to be triple the number on Venus although there are many more small craters. These Martian craters are also far more eroded than are Venus' yet Mars' atmosphere is less than 1/100th the density of Earths... or 9000 times less dense than Venus's atmosphere and wind is supposedly the primary mode of Martian erosion.
All of this seems to be more indicative that Venus is a young planet still experiencing its cooling phase.
No... because I don't think that the CO2 is the cause of the high temperature. It may help maintain it ... a bit.
For the runaway greenhouse effect to take place, the temperature on the planet has to reach first the boiling point of water (100º C) and then the sublimation point (>700º C, I'm told) of the supposed limestone which gets higher and higher as the atmospheric pressure increases. This carbonate and rock sublimation has to occur underground in deep rocks which are excellent insulators.
Perhaps this all happened... but the evidence on Venus has to be looked at in its totality... not based on theories that so far have not been very predictive to real world findings.
Science 6 March 1998: Vol. 279. no. 5356, pp. 1492 - 1497 DOI: 10.1126/science.279.5356.1492 Prev | Table of Contents | Next
Review
Geological Evolution of Venus: Rises, Plains, Plumes, and Plateaus Roger J. Phillips, * Vicki L. Hansen
Crustal plateaus and volcanic rises, major physiographic features on Venus, both formed over mantle plumes. Crustal plateaus were produced by large degrees of plume melting beneath thin lithosphere. The oldest tectonic features in crustal plateaus are ribbon-like troughs indicating early uplift and tensile stretching; their shallow depths suggest that surface temperature there was higher in the past. Widespread volcanic plains, derived from the broad upwellings of internally heated mantle convection, were continually erupted during the time of crustal plateau formation. Discrete volcanic rises, younger than crustal plateaus, formed over a thicker lithosphere, with less plume partial melting. The presence of only one transitional form indicates that the lithosphere thickened rapidly. Thermal and magmatic models show that the formation of these major features can be tied to an expected change in mantle convective style about 1 billion years ago.
(we can argue about the billion years...later.)
And since the gas is CO2, howzit that it is 90 atmospheres and such high temperature — unless the source of heat is internal. :’) The Venusian atmosphere being mostly opaque to the solar radiation that doesn’t get reflected by the high albedo, etc...
I should have pointed out topic from last year about this, sorry.
Unexpected detail in first-ever Venus south pole images
European Space Agency | 13 April 2006 | European Space Agency
Posted on 04/14/2006 2:33:44 AM EDT by raygun
http://www.freerepublic.com/focus/f-news/1614847/posts
Double vortex at Venus South Pole unveiled!
European Space Agency | 27 June 2006
Posted on 07/02/2006 3:25:19 AM EDT by A. Pole
http://www.freerepublic.com/focus/f-news/1659205/posts
Astronomy Picture of the Day
NASA | 5/1/07 | ESA/MPS, Katlenburg-Lindau, Germany
Posted on 05/01/2007 6:37:55 AM EDT by sig226
http://www.freerepublic.com/focus/f-chat/1826398/posts
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According to raw data Venus is massively out of thermal balance. Moreover Sagan’s “super greenhouse theory” to explain the heat is not workable. Descender probes have reported pitch blackness in the middle cloud layer and light at the surface which thus has to be local, created by chemical reactions and heat. Sagan’s greenhouse requires that sunlight reach the surface and it clearly doesn’t.
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