The Kitchen Junk Drawer, Exchanges that need to be put somewhere Options

[Phil Stooke]

So the equatorial orbits are a temporary coincidence, and we don't have to worry about explaining them when we address the question of the satellite origins?

Phil

[Hungry4info]

Indeed.

The group of extrasolar hot Jupiters in retrograde/inclined orbits relative to their star, unless there's a major difference between how it works between rigid and fluid primary bodies, points to a lack of ability to change the inclination of the secondary's orbit via the primary's obliquity.

[stevesliva]

Indeed.

The group of extrasolar hot Jupiters in retrograde/inclined orbits relative to their star, unless there's a major difference between how it works between rigid and fluid primary bodies, points to a lack of ability to change the inclination of the secondary's orbit via the primary's obliquity.

If I'm reading it right, this paper:
http://iopscience.iop.org/1538-3881/135/4/1151/fulltext
seems to hypothesize an "oblateness force" on Phobos and Deimos that keeps them in equatorial orbits throughout Mars obliquity cycle because of relative small sizes and close distances of the moons.

There is another mention somewhere on the web that does say that Mars is coincidentally in the middle of its obliquity cycle at the present time, though.

[Hungry4info]

@stevesliva

Interesting!
I was wrong.
Thanks for that. I've learned something new. I'll have to research this more.

[Phil Stooke]

As I said before, I know nothing about orbital dynamics. But I had thought that an oblate object's equatorial 'bulge' applied a torque on an orbiting moon that pulled it into an equatorial orbit. It doesn't work for our Moon, or Iapetus, because they are too distant. It might not work for those hot Jupiters because the stars are not oblate (or an oblate outer layer has too little mass to have an effect). Can anyone say more? How about Saturn's axial precession? Isn't the whole inner Saturnian system following the planet as it precesses? Seems to me the solar system would be a real mess if this wasn't happening.

Phil

[NW71]

It doesn't work for our Moon, or Iapetus, because they are too distant.

Really interested in this discussion. I too know nothing of orbital dynamics, but the above wasn't always the case was it?

The moon is becoming more distant at about the rate of 4cm a year - roughly the rate your fingernails grow so back before the dinosaurs roamed the Earth the Moon was considerably closer to the Earth. So why did the Moon not become locked in an equatorial orbit?

Neil

[Hungry4info]

With the solar system being roughly coplanar, we might expect that the impactor that formed the moon would have come from the same solar system plane and thus the debris (proto-Lunar disk) would be in roughly the solar system plane, and consequently the Moon as well.

[ngunn]

So why did the Moon not become locked in an equatorial orbit?

Maybe it got locked soon after it's formation but then gradually unlocked as it moved away??

[Hungry4info]

I apparently misread the post I replied to earlier.

The Moon isn't in a perfectly equatorial orbit because of various gravitational effects on the Moon (the sun, others), causing its orbit to vary on fairly short timescales.
So, ngunn is right. At first, the Moon was too deep in Earth's gravitational well to be as severely affected by these various perturbations, but as it drifted out it became more subject to them.

[Shaka]

ADMIN: Moved from this thread. Pointless initial comment and perfectly valid replies ignored.

I certainly agree that these are beautiful images, but I swear I can't see nearly as many blueberries - in the rock matrix - that others are implying in this and other threads. What's wrong with my eyes?!
Is the emperor in his birthday suit or no?
Help!

[Stu]

Who's mentioned berries in this thread? I can find no reference.

[Shaka]

You're right, Stu. I should have taken the time to carefully read the comments. In this thread no one is counting blueberries except me. And I'm getting very low counts. Am I the only one? You've stated in the other thread I just came from, that Ruiz is "bleeding berries". I see nothing of the sort. I'd like to poll the jury on this issue. Is this a reasonable request?

[Stu]

Honestly, you're taking my clearly flippant comment 1) far too literally and 2) far too seriously. Go back to the other thread, see the pic with emerging berries actually ringed to make them easier to see, read my absolutely amateur take on it, then let that bee fly out from under your stone bonnet

[ilbasso]

I anticipate that driving, as well as official site updates (and maybe even site access), will take a hiatus for lack of (fiscal) fuel. Let's hope for a very short pause.

REMINDER: no debates about the underlying cause. Just wanted to alert our non-US readers that barring unforeseen changes, all non-essential US Government functions stop tonight until funding issues are resolved.

[Guest_Sunspot_*]

This same scenario interrupted the Galileo entry probe science transmission... grrr