Does Venus have any kind of resonance with Earth?

Question

I heard somewhere that Venus presents the same side towards Earth at all times (confirmed by Earth-based radar). It might seem to make sense, as Venus produces the third-highest gravitational influence on the Earth, (after the Moon and Sun). Is this possible, even accounting for the sheer distance between the two bodies?

Answer 1

There is a "resonance" but it is that Venus ON AVERAGE presents the same face towards Earth at inferior conjunction. That is when the Sun, Venus and Earth are on the same line (with Venus between the Sun and us). The rest of the time, she shows us the rest of her figure...

However, it is a concidence. The tidal effect of Earth on Venus is infinitesimal compared to the Sun's tidal effect on Venus. The present spin rate of Venus (which is the reason for the coincidence) is entirely due to the Sun's tidal effect, as shown in a paper by Carreia and Laskar.

For an essay (a few years ago) I calculated that the Sun's tidal effect on Venus is 19,230 times that of Earth on Venus at inferior conjuction. At any other time, the ratio is much greater (as Venus moves away from us, our effect is much less).

The tidal effect of the Moon on Earth is also much stronger than the tidal effect of Venus on Earth, by about the same ratio (close to 19,000 times when Venus is closest to us, much more at other times).

Therefore, whatever tidal effect exists between Venus and Earth is insufficient to cause anything.

---

Tidal effect on a given body varies as the mass of the other body and as the inverse of the distance CUBED.

The Moon does present the same face to Earth (it is in captured rotation -- a.k.a. spin lock). Earth's tidal effect on the Moon is over 370,000 times that of Earth on Venus at its closest.

Mercury is in harmonic spin (2:3) -- not in lock spin -- as the sun's tidal effect on Mercury is "only" 50,000 times greater than the Earth-Venus effect.

Answer 2

I'm not sure where you heard this but it's wrong. Earth is just too far from Venus for this type of tidal-locking to occur. (And remember that Venus spends a good deal of time on the opposite side of the sun from us.) The thing about gravity is that it weakens significantly with distance -- it follows the inverse square law, which means that if you move twice as far away from something, the gravitational pull isn't half, it's only 1/4 as strong.

Answer 3

No, that's just the moon.

It has been confirmed that Venusian 'day' is actually longer than its year. The year is 225 earth days and its day is 243 earth days in length. Which is peculiar.

But it doesn't mean that it always faces earth.

I mean - Venus isn't even tidally-locked to the Sun, which exerts a massively greater gravitationally effect on it than the earth could do.

Note that Mercury is tidally locked to the sun, but it isn't a 1:1 ratio. I think its 3:2 or something.

Answer 4

that is postulated that Venus experienced a runaway greenhouse bring about its early history, wherein the temperature greater effective by using beneficial comments till oceans boiled away and it grew to become what that is now. even though it is not reminiscent of Earth in something different than the fundamentals of the greenhouse result, and that is significant to understand that this would't ensue right here as a results of transformations between the two planets.