The Sun Steals Comets from Other Stars

wrote:

http://science.nasa.gov/science-news...v_aliencomets/

The Sun Steals Comets from Other Stars
NASA Science News

Nov. 23, 2010: The next time you thrill at the sight of a comet
blazing across the night sky, consider this: it's a stolen pleasure.
You're enjoying the spectacle at the expense of a distant star.
...
Comets in the Oort Cloud are typically 1 or 2 miles across, and they're
so far away that estimating their numbers is no easy task. But Levison
and his team say that, based on observations, that there should be
something like 400 billion comets there. The "domestic" model of comet
formation can account for a population of only about 6 billion.

I have long thought that galatic interstellar space is peppered with
comets left over from star formation. That is to say the Oort cloud
tapers off more slowly than currently expected to the point the clouds
of stars overlap significantly.

Get fusion drives, start mining the comets, move on to colonizing the
Kuiper belt then Oort cloud, end up having civilization gradually shift
from planets to the comets of interstellar space. Should this model
work, the SETI approach of pointing at stars would be the wrong way to
find interstellar civilizations.

My idea is extremely speculative but eventually fusion drives will be
developed and we'll see what happens in the centuries that follow.

On Nov 24, 9:12*am, Doug Freyburger wrote:
wrote:

http://science.nasa.gov/science-news...3nov_alien...* * *

The Sun Steals Comets from Other Stars
NASA Science News

Nov. 23, 2010: *The next time you thrill at the sight of a comet
blazing across the night sky, consider this: it's a stolen pleasure.
You're enjoying the spectacle at the expense of a distant star.
...
Comets in the Oort Cloud are typically 1 or 2 miles across, and they're
so far away that estimating their numbers is no easy task. But Levison
and his team say that, based on observations, that there should be
something like 400 billion comets there. The "domestic" model of comet
formation can account for a population of only about 6 billion.

I have long thought that galatic interstellar space is peppered with
comets left over from star formation. *That is to say the Oort cloud
tapers off more slowly than currently expected to the point the clouds
of stars overlap significantly.

Get fusion drives, start mining the comets, move on to colonizing the
Kuiper belt then Oort cloud, end up having civilization gradually shift
from planets to the comets of interstellar space. *Should this model
work, the SETI approach of pointing at stars would be the wrong way to
find interstellar civilizations.

My idea is extremely speculative but eventually fusion drives will be
developed and we'll see what happens in the centuries that follow.

We need another green and wet Eden planet that's naked Goldilocks
approved to pillage, plunder and trash, as well as best if it's
already populated by voodoo snookered and dumbfounded heathens, so
that we'll have an unlimited supply of slaves and minions to worship
everything and anything we say, do or touch.

~ BG

On 25/11/2010 4:12 AM, Doug Freyburger wrote:
wrote:

http://science.nasa.gov/science-news...v_aliencomets/

The Sun Steals Comets from Other Stars
NASA Science News

Nov. 23, 2010: The next time you thrill at the sight of a comet
blazing across the night sky, consider this: it's a stolen pleasure.
You're enjoying the spectacle at the expense of a distant star.
...
Comets in the Oort Cloud are typically 1 or 2 miles across, and they're
so far away that estimating their numbers is no easy task. But Levison
and his team say that, based on observations, that there should be
something like 400 billion comets there. The "domestic" model of comet
formation can account for a population of only about 6 billion.

I have long thought that galatic interstellar space is peppered with
comets left over from star formation. That is to say the Oort cloud
tapers off more slowly than currently expected to the point the clouds
of stars overlap significantly.

I don't really see how they can overlap, in the sense that there's a
region of space that contains both comets belonging to star A and comets
belonging to star B. It would require that two comets belonging to two
stars, where the comets share a common point of apoapsis, be
nevertheless required to accelerate in opposite directions at that
point, even though they must experience the same net gravitational force
per unit mass.

There might be comets that are in figure of eight orbits about two
stars, and I suppose that relative star motion could lead to a comet
that was originally orbiting one star being captured by another.

Sylvia.

On Dec 6, 3:18*am, Sylvia Else wrote:
On 25/11/2010 4:12 AM, Doug Freyburger wrote:



wrote:

http://science.nasa.gov/science-news...10/23nov_alien....

The Sun Steals Comets from Other Stars
NASA Science News

Nov. 23, 2010: *The next time you thrill at the sight of a comet
blazing across the night sky, consider this: it's a stolen pleasure.
You're enjoying the spectacle at the expense of a distant star.
...
Comets in the Oort Cloud are typically 1 or 2 miles across, and they're
so far away that estimating their numbers is no easy task. But Levison
and his team say that, based on observations, that there should be
something like 400 billion comets there. The "domestic" model of comet
formation can account for a population of only about 6 billion.

I have long thought that galatic interstellar space is peppered with
comets left over from star formation. *That is to say the Oort cloud
tapers off more slowly than currently expected to the point the clouds
of stars overlap significantly.

I don't really see how they can overlap, in the sense that there's a
region of space that contains both comets belonging to star A and comets
belonging to star B. It would require that two comets belonging to two
stars, where the comets share a common point of apoapsis, be
nevertheless required to accelerate in opposite directions at that
point, even though they must experience the same net gravitational force
per unit mass.

There might be comets that are in figure of eight orbits about two
stars, and I suppose that relative star motion could lead to a comet
that was originally orbiting one star being captured by another.

Sylvia.

There's by far more rogue stuff out there of 5+ km than we have stars
in this universe (we're talking at least 1e25 items, if not 1e26), and
Oort clouds do interact from time to time, as well as massive enough
intruders do pass nearby enough to perturb otherwise stable comet,
asteroid and planetoid items. Sirius and its Oort cloud is currently
putting a gravitational load or force upon our Oort cloud, and
eventually these Oort clouds will interact.

~ BG

Sylvia Else wrote:
Doug Freyburger wrote:

I have long thought that galatic interstellar space is peppered with
comets left over from star formation. That is to say the Oort cloud
tapers off more slowly than currently expected to the point the clouds
of stars overlap significantly.

I don't really see how they can overlap, in the sense that there's a
region of space that contains both comets belonging to star A and comets
belonging to star B.

Comets are very far apart. The zones could overlap without significant
interaction. There would be a small number of close encounters that
cause a comet to drop towards one star or another and more that point
both objects away from either star. There would be near zero
collisions. There would be gravitational influence by other stars,
which is already a known effect.

It would require that two comets belonging to two
stars, where the comets share a common point of apoapsis, be
nevertheless required to accelerate in opposite directions at that
point, even though they must experience the same net gravitational force
per unit mass.

There's no such requirement. Comets formed in a dust cloud might or
might not be bound to a star. Comets near stars might or might not be
perturbed to the vicinty of some other star.

There might be comets that are in figure of eight orbits about two
stars,

Fun sounding but no need.

and I suppose that relative star motion could lead to a comet
that was originally orbiting one star being captured by another.

In addition to most comets simply being well out in interstallar space a
long time after leaving the dust cloud where they were formed. Maybe
within a few light days of a star maybe not.

On 7/12/2010 7:06 AM, Doug Freyburger wrote:
Sylvia Else wrote:
Doug Freyburger wrote:

I have long thought that galatic interstellar space is peppered with
comets left over from star formation. That is to say the Oort cloud
tapers off more slowly than currently expected to the point the clouds
of stars overlap significantly.

I don't really see how they can overlap, in the sense that there's a
region of space that contains both comets belonging to star A and comets
belonging to star B.

Comets are very far apart. The zones could overlap without significant
interaction. There would be a small number of close encounters that
cause a comet to drop towards one star or another and more that point
both objects away from either star. There would be near zero
collisions. There would be gravitational influence by other stars,
which is already a known effect.

I wasn't talking about interactions between comets.


It would require that two comets belonging to two
stars, where the comets share a common point of apoapsis, be
nevertheless required to accelerate in opposite directions at that
point, even though they must experience the same net gravitational force
per unit mass.

There's no such requirement. Comets formed in a dust cloud might or
might not be bound to a star. Comets near stars might or might not be
perturbed to the vicinty of some other star.

If a comet is not bound to a star, then it wouldn't be in the Oort cloud
of the star, so the issue of Oort clouds overlapping wouldn't arise. To
discuss overlapping Oort clouds, you have to be discussing those comets
that are bound to their respective stars. I'm saying that this situation
cannot exist.

There might be comets that are in figure of eight orbits about two
stars,

Fun sounding but no need.

and I suppose that relative star motion could lead to a comet
that was originally orbiting one star being captured by another.

In addition to most comets simply being well out in interstallar space a
long time after leaving the dust cloud where they were formed. Maybe
within a few light days of a star maybe not.

That's as maybe, it has nothing to do with the overlapping of Oort clouds.

Sylvia.

Sylvia Else wrote:
Doug Freyburger wrote:

Comets formed in a dust cloud might or
might not be bound to a star. Comets near stars might or might not be
perturbed to the vicinty of some other star.

If a comet is not bound to a star, then it wouldn't be in the Oort cloud
of the star, so the issue of Oort clouds overlapping wouldn't arise. To
discuss overlapping Oort clouds, you have to be discussing those comets
that are bound to their respective stars. I'm saying that this situation
cannot exist.

Bound is a floating point but a binary number. For an object several
light days out the degree of binding is tiny. The notion that a comet
is bound to a star is more about sharing its motion relative to other
nearby stars than about having an orbit that can be projected more than
one orbit.

To me that means the field of comets tapers off very gradually across
interstellar space so the only way to tell which star a comet is related
to is its motion relative to other stars.

Cometary bombardment of inter system bodies will have dropped off on an
expontenial as the inter system got swept of material to form planets.
It's a process that never completely stops but at some point the number
of comets from other systems will be as large as the number left over
from the formation of the system. The older the star the more the
overlap with other stars. Four billion years is a lot of time to mix
comets.