Planet Venus query

[Fax_Monkey]

Hi just wondered . . .

Is it possible that Venus was an outer system planet at some stage - it seems to spin the wrong way.
If the planet had been an outer system body - bumped into the inner system
are there any geological/ orbital indicators that could indicate or deny an outer system origin.

Thanks

 

[MeteorWayne]

Possible, well sure anything is. But likely?, No. Venus is much more like the inner 4 planets than the outer 4. As for it's rotation, analysis of interaction of eccentricty and alignment of the inner 4 planets, with some influence from Jupiter has created one explanation that the rotation rate is a result of those gravitational effects.

 

[crazyeddie]

Another explanation of the origin of the slow, retrograde rotation of Venus is that like the Earth, it, too, may have been smacked by a large planetesimal early in it's history. Unlike the impact that created the Earth's moon, however, the one that hit Venus was at an angle that robbed the planet of it's angular momentum, instead of adding to it.

 

[ZenGalacticore]

Maybe its retrograde motion has something to do with the original Jovian "roaster" that is now the base-core remnant of Mercury.

If a Jupiter-sized planet fell inward towards the Sun (like some of the various exo-Jovian "roasters" we've detected), could it have come close enough to Venus to screw around with its rotation?

Just a thought.

 

[Fax_Monkey]

Wayne - thanks for the heads up on gravitation eccentricity- ive never heard of that before.
Crazy - any impact should have left physical scarring in the crust - ill have to check
surface mapping to see if there are any clues.
Zen - Thats a good point about baked Mercury, if it is most of the core from an old rogue planet
would that mean it was a gas giant getting blow torched just leaving the core behind?
and could we estimate it's original size if we compared it to the cores of other gas bodies?

right maps of venus - should be on the site somewhere!

Thanks for the help guys.

 

[3488]

I am sorry to say, but Mercury is not an exposed core. Mercury's high average global density has more to do with the location of the formation of Mercury within the inner edge of the protoplanetary disk.

If Jupiter or Saturn were moved to Mercury's orbit, they would NOT evaporate (they would in the future as the Sun continues to brighten), their escape velocities are too great. Mercury's surface in places is so old that it records the impact history from the formative period, though some 30% of Mercury's surface is certainly very much younger owing to volcanic activity.

Whilst it would be fantastic to have an exposed core of a vapourized Gas Giant, but we don't. Sorry guys.

Venus's slow retrograde rotation is most likely an impact during the formative period, more or less as crazyeddie says, perhaps tidal influences with Jupiter coupled with that has done this.

Andrew Brown.

 

[ZenGalacticore]

3488- Well, I did pose it as a speculative question, not a statement of fact.

I have read an article where some astronomers played with the idea of Mercury being a remnant core. But I'm sure you are more updated on the subject than I.

 

[3488]

Sorry Zen,

I did not mean to come over like that.

I do keep up with Mercury research & the MESSENGER mission closely.

You are correct, in that theory has been toyed around with, but Mariner 10 & MESSENGER data do rule out the exposed core theory for Mercury.

It would be fascinating if there was an exposed core in our solar system to examine up close & even land on, it really truly would be, but unfortunately Mercury isn't one.

Eventually when intersteller spaceprobes become possible, we may find one around Alpha Centauri A or B, Sirius, Procyon, Delta Pavonis, etc, who knows?????

We are living in interesting times & there are certainly more coming up.

Andrew Brown.

 

[ZenGalacticore]

3488- You didn't come across in any negative way. I was just clarifying my viewpoint. (I'm actually relatively new to this instantaneous blogging/posting thing. Didn't get online until 2007!. I'm in some ways 10 years behind. But that can be a good thing, as I got to watch the entire 11 years of Kelsey Grammer's "Frasier" in 3 months. :lol: )

Perhaps it was wishful thinking on the part of the astronomer and, IIRC, the planetary scientist, that wrote the article about Mercury possibly being a remnant core of a former Jovian. It was a fairly recent article, btw. All the more reason to wonder if it was just wishful thinking on their part.

And yeah, wish we could all live to see interstellar probes. More importantly, live long enough to receive the info back across the light-years!

Zen.