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Venus Express press conference November 28th, Venus: a more Earth-like planetary neighbour
belleraphon1
post Nov 20 2007, 12:27 PM
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All..

Venus Express press conference set for November 28th.

http://www.esa.int/esaCP/SEMX1C63R8F_index_0.html

‘Venus: a more Earth-like planetary neighbour’
Latest results from Venus Express
28 November 2007, 15:00, room 137
ESA Headquarters, 8-10 rue Mario-Nikis, Paris

15:00 Introduction, by Håkan Svedhem, ESA Venus Express Project Scientist
15:07 Venus: What we knew before, by Fred Taylor, Venus Express Interdisciplinary Scientist

15:15 Temperatures in the atmosphere of Venus, by Jean-Loup Bertaux, SPICAV Principal Investigator

15:25 The dynamic atmosphere of Venus, by Giuseppe Piccioni, VIRTIS Principal Investigator

15:40 Venus’s atmosphere and the solar wind, by Stas Barabash, ASPERA Principal Investigator

15:50 Climate and evolution, by David Grinspoon, Venus Express Interdisciplinary Scientist

16:00 Conclusion, by Dmitri Titov, Venus Express Science Coordinator and VMC scientist

16:05 Questions and Answers

16:25 Individual interviews

17:30 End of event

Craig
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hendric
post Nov 30 2007, 07:44 PM
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QUOTE (Juramike @ Nov 30 2007, 12:15 PM) *
Maybe Venus is what Earth should look like if it hadn't been for a lucky strike or two?


I don't think it's the lucky strike syndrome, but more "location location location". Once a terrestrial planet gets warm enough that it's H2O starts significantly evaporating, the endgame looks like Venus. In a billion years or so, once the Sun's output increases enough, Earth will rapidly evolve into a Venus near-twin.

The hardest part of this scenario to explain, for me, is why the massive cloud cover generated by an ocean starting to evaporate wouldn't block enough sunlight to keep it in equilibrium. I recall reading somewhere that the actual solar heat input at the surface of Venus is less than Earth due to the clouds, but the percentage kept is of course much higher.

QUOTE (nprev @ Nov 30 2007, 12:28 PM) *
Seriously, though, to me this seems as if Venus had a very slow rotation period from the outset, and the fact that it comes fairly close to Earth (25 million miles) might have been just enough to brake its rotation into the current resonance. Maybe all that went wrong is that it didn't get smacked in the right way to get it spinning right (in fact, it probably got smacked the wrong way to slow it down in the first place.)


I think the big player in Venus rotational evolution has got to be the Sun. Any effect from Earth would have to be very very small. That said, it's possible, and the fact that there is a very close synchronicity is interesting. But given that the other reasonably large objects in the inner solar system (excluding Mercury, but including Earth, Mars, Ceres and Vesta) have fast rotations, I'd lean towards Venus starting at a similar rate.

Here's a wild hypothesis. What if Venus was just like Earth, but never got hit by that last Mars-sized object to strip away it's outer crust & volatiles? Perhaps this left Venus with a <b>larger</b> amount of water than Earth, setting it up for a massive runaway greenhouse at the right time in the Sun's evolution? To be a worthwhile theory though, it needs to make a prediction...Umm, on the one piece of Venusian ground at the top of Maxwell Montes is a giant titanium sign written in Venusian that says "Don't burn carbon based fuels Earthlings". smile.gif

QUOTE (elakdawalla @ Nov 30 2007, 12:31 PM) *
All that atmosphere is just a pesky obstruction to Venus' cool geology.


Pesky obstruction? That atmosphere caused much of that cool geology, if present theories are accurate. smile.gif


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AndyG
post Dec 1 2007, 02:00 PM
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QUOTE (hendric @ Nov 30 2007, 07:44 PM) *
...at the top of Maxwell Montes is a giant titanium sign written in Venusian that says "Don't burn carbon based fuels Earthlings". smile.gif


Wouldn't those metal snows on the tops of these mountains make lightning strikes probable, at the very least?

Andy (edit for spelling)
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JRehling
post Dec 1 2007, 04:30 PM
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QUOTE (AndyG @ Dec 1 2007, 06:00 AM) *
Wouldn't those metal snows on the tops of these mountains make lightning strikes probable, at the very least?

Andy (edit for spelling)


I would guess that they would contribute almost zero. A cloud-ground discharge will take place if the resistance is overcome. Adding a thin layer of conductor doesn't reduce the total resistance (from air, mainly).

By analogy, it's like wondering if your money would go farther if an expense of zero were added to your budget. That neither hurts nor helps. If it REPLACED some other positive expense, then it would help. So a tall tower of copper might increase the probability of a lightning strike, but a thin flat layer shouldn't.

In any event, the best chance for lightning on Venus is cloud-cloud, with the resistance being a lot less than in the huge vertical groundtrack. There are no cumulus clouds on Earth ever nearly as high as all of the clouds are on Venus.

Even on Earth, I'm not sure that metal towers really increase the number of lightning strikes in a given locale significantly. Only to the extent that the height of the tower was a significant fraction of the cloud height (like the Empire State Building). Otherwise, they mainly just determine where it hits. (Eg, the tower instead of 20 meters north of the tower.)
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Posts in this topic
- belleraphon1   Venus Express press conference November 28th   Nov 20 2007, 12:27 PM
- - belleraphon1   Also... The results will appear in a special sec...   Nov 20 2007, 12:29 PM
- - cndwrld   Press Conference Results The press conference res...   Nov 28 2007, 08:07 PM
- - nprev   To say nothing of Venus' past. It looks as if ...   Nov 29 2007, 12:59 AM
- - Zvezdichko   Venus Express is not the first spacecraft to detec...   Nov 29 2007, 02:45 PM
|- - tedstryk   There was always controversy surrounding that. No...   Nov 29 2007, 03:08 PM
|- - JRehling   QUOTE (tedstryk @ Nov 29 2007, 07:08 AM) ...   Nov 29 2007, 07:30 PM
|- - JRehling   QUOTE (JRehling @ Nov 29 2007, 11:30 AM) ...   Nov 30 2007, 05:43 PM
- - edstrick   CT Russell is one of the partisan participants in ...   Nov 30 2007, 11:38 AM
- - Julius   I am no planetary sceintist but just a humble enth...   Nov 30 2007, 11:57 AM
|- - JRehling   QUOTE (Julius @ Nov 30 2007, 03:57 AM) I ...   Nov 30 2007, 05:20 PM
||- - Juramike   QUOTE (JRehling @ Nov 30 2007, 12:20 PM) ...   Nov 30 2007, 06:15 PM
|- - hendric   QUOTE (Julius @ Nov 30 2007, 05:57 AM) I ...   Nov 30 2007, 05:37 PM
|- - elakdawalla   QUOTE (hendric @ Nov 30 2007, 09:37 AM) I...   Nov 30 2007, 06:31 PM
- - nprev   Let's not forget that there's a poorly und...   Nov 30 2007, 06:28 PM
- - hendric   QUOTE (Juramike @ Nov 30 2007, 12:15 PM) ...   Nov 30 2007, 07:44 PM
|- - Juramike   QUOTE (hendric @ Nov 30 2007, 02:44 PM) H...   Nov 30 2007, 08:03 PM
||- - Julius   QUOTE (Juramike @ Nov 30 2007, 09:03 PM) ...   Nov 30 2007, 09:26 PM
||- - vjkane   As I remember, one of the puzzles of planetary sci...   Dec 1 2007, 12:30 AM
||- - JRehling   QUOTE (vjkane @ Nov 30 2007, 04:30 PM) As...   Dec 1 2007, 01:00 AM
||- - mcaplinger   QUOTE (JRehling @ Nov 30 2007, 05:00 PM) ...   Dec 1 2007, 02:33 AM
||- - Tom Tamlyn   So also is the existence of a large moon (product ...   Dec 1 2007, 02:38 AM
||- - brellis   The other day, I found a copy of David Grinspoon...   Dec 1 2007, 06:11 AM
||- - JRehling   QUOTE (brellis @ Nov 30 2007, 10:11 PM) T...   Dec 1 2007, 08:08 AM
|- - AndyG   QUOTE (hendric @ Nov 30 2007, 07:44 PM) ....   Dec 1 2007, 02:00 PM
|- - JRehling   QUOTE (AndyG @ Dec 1 2007, 06:00 AM) Woul...   Dec 1 2007, 04:30 PM
- - edstrick   Regarding the lack of magnetic field... 1) Venus ...   Dec 1 2007, 10:26 AM


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