Venus MAY Have had a Moon

[TeaTime]

Did Venus once have a moon? A talking point with some interesting
references:

http://skytonight.com/news/4353026.html
http://www.sciam.com/article.cfm?articleID=0008DCD1-0A66-152C-8A6683414B7F0000&ref=sciam
http://www.solarviews.com/eng/hypothet.htm#neith

[Jonathan Silverlight]

In message <Dzw4h.25174$Ib....@newsfe1-gui.ntli.net>, TeaTime
<lickns...@hotmail.com> writes

Isn't there some question as to whether Venus owes its rotation to one
impact, let alone two? The Wikipedia page
<http://en.wikipedia.org/wiki/Venus> links to a paper in Icarus saying
tidal slowing of the atmosphere may have produced its current state
<http://www.imcce.fr/Equipes/ASD/preprints/prep.2002/venus1.2002.pdf>
The moons of Mars didn't form by collision - I don't think anyone has a
sensible theory for them :-)

[TeaTime]

"Jonathan Silverlight" <jsilve...@spam.merseia.fsnet.co.uk.invalid> wrote
in message news:LfhU7bb2...@ntlworld.com...

> Isn't there some question as to whether Venus owes its rotation to one
> impact, let alone two? The Wikipedia page
> <http://en.wikipedia.org/wiki/Venus> links to a paper in Icarus saying
> tidal slowing of the atmosphere may have produced its current state

Yes, certainly a possibility, although popular theories for Venus do suggest
a catastrophic collision which put its axis/rotation in the retrograde.
Tidal action of the Earth on Venus, acting steadily for billennia, then
established the 3:2 spin-orbit resonance. Every 2 earth years, the exact
same 'side' of the Venusian surface faces Earth. So maybe there is some
sub-surface mass concentration on this area of Venus that the Earth pulls on
to create the tidal lock ... a mascon created by the collision perhaps?
Hopefully a lot more data will be forthcoming shortly.

> <http://www.imcce.fr/Equipes/ASD/preprints/prep.2002/venus1.2002.pdf>
> The moons of Mars didn't form by collision - I don't think anyone has a
> sensible theory for them :-)

They are ugly little blighters, aren't they. At first glance, one sees
captured asteroids (or even comets) but apparently there is much scientific
opinion to the contrary. Glad we don't have a chunk of rock like Phobos
orbiting the earth at just a few thousand miles up.