Did Venus Have A Moon? Options

[nprev]

...or two?

http://skytonight.com/news/home/4353026.html

[RNeuhaus]

...or two?

http://skytonight.com/news/home/4353026.html

So that it would be probed, Venus must show any impact marks of two moons.

Does the Magallen's radars show any indication of these impacts? I haven't heard of anyone speculating about this. However, I seems that it would be very hard to prove since at about 500 millions years ago Venus might have undergone a big volcan eruption that have resurfaced most of the planet.

Anyway, due to its odd direction of its polar spin, there must have some kind of impact that have changed its polar position and not due to the influence of Sun tidal and the Venusian's massive atmosphere in which they are, most probably, be impossible to alter the polar positions.

On the other hand, I think that the changing the rotation way by reversing the poles is lower than by reversing the rotation direction which would be twice force than the polar's one. So, this kind of mystery would continue...and hope to attract more spacecraft to visit to Venus.

Rodolfo

[JRehling]

So that it would be probed, Venus must show any impact marks of two moons.

Does the Magallen's radars show any indication of these impacts? I haven't heard of anyone speculating about this. However, I seems that it would be very hard to prove since at about 500 millions years ago Venus might have undergone a big volcan eruption that have resurfaced most of the planet.

On the other hand, I think that the changing the rotation way by reversing the poles is lower than by reversing the rotation direction which would be twice force than the polar's one. So, this kind of mystery would continue...and hope to attract more spacecraft to visit to Venus.

Rodolfo

Venus does not show any such features, although you correctly note that it might have been covered by volcanism -- we aren't seeing very much of Venus's full history on its surface.

Note, though, just how slow Venus is rotating: 4 miles per hour = 6.5 km/hour. It doesn't take much of an input to that system to make whatever change you would like.

The low inclination is another argument for a solar-tide basis to Venus's rotation.

I suggested a few years ago that Mercury may bear the impact scar of a satellite that "augured in". There is a large radar feature called "Feature C" that is near the equator and 240 West longitude -- an area not imaged by Mariner 10. That area shows nothing especially compelling in albedo maps made with Earth-based telescopy, but neither does the estimable Caloris basin, which simply isn't much of an albedo feature. There is another proposed near-equatorial basin that has perhaps been imaged as a *relief* feature casting shadows of a double-rimmed basin, around 270 West longitude. We will find out more about the anti-Mariner hemisphere of Mercury when Messenger makes its initial flybys and then enters orbit.