And is he suggesting that the asteroid's atmosphere travelled with it from the earth as it roared away at escape velocity?
Asteroid and Meteoroid Not a Coincidence
- Thread starter Jefferson
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And is he suggesting that the asteroid's atmosphere travelled with it from the earth as it roared away at escape velocity?
In that scenario, it would certainly be expected to drag some atmosphere in the partial vacuum behind it.
Really? And as it tumbles through earth's atmosphere at escape velocity of 26K mph at the surface, which the object must reach immediately in Brown's fantasy because there is no continuing propulsive force as in a rocket launch, how does it drag something behind it without that something vaporizing?
The asteroid wasn't said to hold the atmosphere.
It was said to vent gas and water molecules creating a temporary atmosphere.
There is no other reasonable way asteroids could capture moons.
gcthomas
New member
Except for collisions and gravitational interactions, no other reasonable way at all.
this temporary atmosphere allows asteroids to capture moons?
Any comment on how Dr. Brown explains the instantaneous 26K mph speed given to all these asteroids and comets? And how he keeps them from vaporizing as a result of friction? that pesky 2nd Law that you guys always drag out?
Hard of reading, aren't you?
The typical speed of a collision between asteroids would be utterly destructive and scatter both.
Frayed Knot
New member
Oh, so the typical speed of collisions is the speed that every single one of them occurs at? Or would there be a distribution of speeds, and some would be much slower than others?
How does the existence of an atmosphere on an asteroid aid in capturing another body?
Lordkalvan
New member
Professor? Can you tell us?
Lordkalvan
New member
How do you figure that?
Lordkalvan
New member
Really, Professor? Can you tell us why that is? Do you have any evidence to support your assertions?
Lordkalvan
New member
So what's that 'typical speed', Professor? Got any examples? How about some maths to show us this 'utterly destructive' scattering effect?
It's funny how many asteroids seem to be the result of collisions, including the one you invoked to support Wacky Wally's ideas in the first place, Itokawa, which shows evidence of collisions without 'utterly destructive' scattering.
It's also funny how Wally references asteroids formed from 'rubble piles' as evidence for the hydropants' theory when, according to the Professor, such collisions of material as came together would be 'utterly destructive'. Any comments on your falsification of Wally's ideas, Professor?
Lordkalvan
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The Professor doesn't seem to have considered the concept of overtaking or grazing collisions.
Lordkalvan
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I think various posters have tried to elicit this information from the Professor already, but he seems reluctant to explain it to us.
gcthomas
New member
Ahh, the old 'hard of reading' gag. Nice to see you rolling that out so often!
They vary hugely, of course. Slow moving asteroids can join to make a larger one (all the bone shaped asteroids are probably of this type).
An asteroid struck by a fast smaller one can have multiple fragments knocked off, some of which might leave slowly enough to remain gravitationally bound to the parent, while the others become independent asteroids. This is supported by the fact that many binary asteroids are also members of spectroscopic families of asteroids.
Earth crossing asteroids have moons that orbit much closer than main belt ones, and these may have formed through close passes of Earth or the other minor planets. Tidal stresses can fragment the asteroid, leaving closely orbiting pieces. See an example paper here.
Lordkalvan
New member
So nothing about atmospheres, then? Maybe the authors of the paper should have consulted with Wally before reaching their obviously ill-informed conclusions?Ahh, the old 'hard of reading' gag. Nice to see you rolling that out so often!
They vary hugely, of course. Slow moving asteroids can join to make a larger one (all the bone shaped asteroids are probably of this type).
An asteroid struck by a fast smaller one can have multiple fragments knocked off, some of which might leave slowly enough to remain gravitationally bound to the parent, while the others become independent asteroids. This is supported by the fact that many binary asteroids are also members of spectroscopic families of asteroids.
Earth crossing asteroids have moons that orbit much closer than main belt ones, and these may have formed through close passes of Earth or the other minor planets. Tidal stresses can fragment the asteroid, leaving closely orbiting pieces. See an example paper here.
The relative speed is certainly a range. But the speed required for moon capture (also requiring the atmosphere) is so low, it'd almost never happen. And because asteroid moons are plentiful, you need to explain the facts with a workable process.
You could read the description I posted, troll. :troll:
It always seems so necessary. :idunno:
Sorry, you're appealing to concepts that aren't available in reality. "Slow moving" asteroids? Firstly, it is the relative speed of two asteroids that is the concept. Secondly, they have to be the norm, not an exception.
Nope. Anything thrown off an asteroid will either fall back down or fly away forever. It will not fly up and then suddenly make a 90o turn and start on an orbital path.
What is that?
And as many as this might create (extremely few, if any) it would also destroy.
Lordkalvan
New member
So is the Professor retracting his earlier assertion about asteroid collisions being 'utterly destructive'?
How 'low' does 'the speed required for moon capture' have to be?
Can the Professor show how and why an atmosphere is required for an asteroid to capture a moon?
Can the Professor also show us how 'plentiful' asteroid moons are?
What 'description' was that, Professor? Can you link to it or indicate the post number? If it was the extensive C&P from Wally Brown's seminal work, that was little more than enthusiastic handwaving.
I suppose the Professor finds insults easier than explanations.
As such concepts seem to underlie much of the Professor's posts, he rather seems to be in the position of a pot calling a kettle black.
Can the Professor clarify what he means? Does he have evidence concerning 'relative speeds' of colliding or grazing asteroids? Can he explain why 'they have to be the norm, not an exception'.
The Professor seems to be confused and contradicting the Wally Brown hypothesis of asteroid formation. Can he explain this falsification of Brown's hypothesis? Can he also provide evidence in the form of calculations to show that the only alternatives for débris created by asteroid collisions are for it to 'fall back down or fly away forever'?
Researching the Baptistina Asteroid Family might help the Professor understand this.
Can the Professor support this assertion, or are we simply to take his word for it?
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gcthomas
New member
Approx 2% of asteroids have moons, according to the surveys. If two asteroids are in almost the same orbit, then the relative speeds will be very low. There are plenty of contact binary asteroids that show that collision speeds can be very low indeed.
When I am talking about slow asteroid collisions, what else would I mean? ALL speeds are measured relative to something, and I thought this was obvious. (I didn't mention absolute speeds - did you think I meant that?)
You assume that all asteroid moons are in circular orbits. Most asteroid moons are in quite elliptical orbits, so 90 deg turns are not necessary. And with several objects launched into very elliptical orbits, collisions and amalgamation of these will tend to circularise somewhat the orbits by averaging the motions.
Google is your friend!
Yes. Only needs to be a few percent. And? The ones that are left may have tidally produced moons. This is a problem how?