Comet from another star?

On a more serious note, devoid of any anime nonsense, it seems to me
that the energy requirements to intercept an extrasolar comet on a
hyperbolic trajectory would be too great.
Too much fuel would be needed to even catch up to it.


Not if the probe used an ion engine like the one used by DS2. Or maybe
this would a good mission use Dr. Franklin Chang-Diaz's VASIMR engine.

Link: http://en.wikipedia.org/wiki/Variabl...oplasma_Rocket

wrote in message
...

On a more serious note, devoid of any anime nonsense, it seems to me
that the energy requirements to intercept an extrasolar comet on a
hyperbolic trajectory would be too great.
Too much fuel would be needed to even catch up to it.


Not if the probe used an ion engine like the one used by DS2. Or maybe
this would a good mission use Dr. Franklin Chang-Diaz's VASIMR engine.

Link:
http://en.wikipedia.org/wiki/Variabl...oplasma_Rocket

That's true but it's wrong. You fire your rocket engine
to accomplish a vectored delta v. That's how you get
around in space until someone comes up with something
better. The orbit changes to catch the hyperbolic comet
and then to return are the same whether you use an ion
engine, a VASIMR, or that extra F2 engine you had along
with you, and its (massive) huge tanks of fuel.

I think if your probe has people aboard, your outgoing
and return firings would act too slowly for that. I do
expect engines of greater thrust eventually, but then,
where do they get the electric energy which they then
make into thrust?

Titeotwawki -- mha [sci.space.policy 2006 Dec 06]

On Dec 5, 11:03*pm, "Martha Adams" wrote:
" wrote in message

...
On Dec 4, 1:12 pm, Pat Flannery wrote:

Sounds like a great beginning for a 1950's Sci-Fi movie
plot:http://www.msnbc.msn.com/id/28023860/
Seriously, if it is from another star system, this would be worth
getting a sample return mission to.
So we sent out a probe to do a flyby of it... and as the probe
approached, we first saw written on the surface of the comet those
words
of terror that could spell the doom of mankind: "Space Battleship
Yamato
is destroyed...all your anime are belong to us." :-D

On a more serious note, devoid of any anime nonsense, it seems to me
that the energy requirements to intercept an extrasolar comet on a
hyperbolic trajectory would be too great.
Too much fuel would be needed to even catch up to it.

=======================

And twice over! *You joined an object in a hyperbolic
orbit and it's going *out*. *So now you must kill your
hyperbolic velocity and develop an appropriate return
orbit, this is going to be a pretty wild mission.

Actually, re that object from another star, how do you
know that's what it is? *I'd expect such an object at
first approximation, to be practically indistinguishable
from something local.

Unless, of course, it turned out to be a *made* object,
like a spacecraft or an aldrin cycler kind of thing.

Titeotwawki -- mha *[sci.space.policy 2008 Dec 15]

I would apply Occam's Razor here.
More likely to be a dirty iceball than an artificial object.

On Dec 5, 12:50*pm, Pat Flannery wrote:
wrote:
On a more serious note, devoid of any anime nonsense, it seems to me
that the energy requirements to intercept an extrasolar comet on a
hyperbolic trajectory would be too great.
Too much fuel would be needed to even catch up to it.

This one has entered a short period solar orbit:http://en.wikipedia.org/wiki/96P/Machholz

Pat

A better source for this information:
http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=96P%2FMachholz+1

I do not trust Wikipedia for anything as any bozo can edit it.

On Dec 6, 2:38*am, "Martha Adams" wrote:
wrote in message

...



On a more serious note, devoid of any anime nonsense, it seems to me
that the energy requirements to intercept an extrasolar comet on a
hyperbolic trajectory would be too great.
Too much fuel would be needed to even catch up to it.

Not if the probe used an ion engine like the one used by DS2. Or maybe
this would a good mission use Dr. Franklin Chang-Diaz's VASIMR engine.

Link:
http://en.wikipedia.org/wiki/Variabl...Magnetoplasma_...

That's true but it's wrong. *You fire your rocket engine
to accomplish a vectored delta v. *That's how you get
around in space until someone comes up with something
better. *The orbit changes to catch the hyperbolic comet
and then to return are the same whether you use an ion
engine, a VASIMR, or that extra F2 engine you had along
with you, and its (massive) huge tanks of fuel.

I think if your probe has people aboard, your outgoing
and return firings would act too slowly for that. *I do
expect engines of greater thrust eventually, but then,
where do they get the electric energy which they then
make into thrust?

Titeotwawki -- mha *[sci.space.policy 2006 Dec 06]

Besides the engineering problems, you have to convince the politicians
that a mission would be worth the federal dollars to go there.

On Dec 4, 1:12*pm, Pat Flannery wrote:
Sounds like a great beginning for a 1950's Sci-Fi movie plot:http://www.msnbc.msn.com/id/28023860/
Seriously, if it is from another star system, this would be worth
getting a sample return mission to.
So we sent out a probe to do a flyby of it... and as the probe
approached, we first saw written on the surface of the comet those words
of terror that could spell the doom of mankind: "Space Battleship Yamato
is destroyed...all your anime are belong to us." :-D

Here is a graphical representation of the comet's orbit. Note the
proximity to Jupiter, which captured the comet into a heliocentric
orbit:

http://s432.photobucket.com/albums/q...Machholtz1.jpg

wrote:

I do not trust Wikipedia for anything as any bozo can edit it.


Hey, hey, hey....we don't have to be cruel...we don't have to be cruel.
I edited the stuff on the Giant Squid (most of which I added is now
obsolete; I've got to get back over there again and see if what I wrote
has been corrected by anyone with the new data on our favorite real sea
monster, particularly regarding its reproduction, which may be stranger
than anyone ever imagined).
....and the Tullimonstrum (which is still current, as very little is
known with certainty about this odd little prehistoric critter).
If you think there is something wrong with the description of the comet
on Wikipedia, then don't criticize the article - go over and correct it.
:-)

Pat

"OM" wrote in message
...
On Sat, 06 Dec 2008 23:42:46 -0600, Pat Flannery
wrote:

I've got to get back over there again and see if what I wrote
has been corrected by anyone with the new data on our favorite real
sea
monster

...Or reverted by some teenage limey catamite who thinks s/he owns the
article because they used two dozen sock puppets to vote themselves
admin powers. You'd be surprised at the number of admins who pulled
that stunt to get their admin rights.
OM

--

]=====================================[
] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[

It's off topic ... when I see text like this, I think
it illustrates the kind of family its writer grew up
in. Grew up? Well, I mean in a calendar sense here.

Titeotwawki -- mha [sci.space.policy 2008 Dec 8]

Martha Adams wrote:

It's off topic ... when I see text like this, I think
it illustrates the kind of family its writer grew up
in. Grew up? Well, I mean in a calendar sense here.

To lighten things up a bit:
TEDDY BEARS... _IN SPACE_!:
http://uk.news.yahoo.com/21/20081204...e-6323e80.html
Well, actually, the floated up there rather than being blasted up there
on a rocket.
But hey, they did get up there, and the photo's well worth seeing.
It's a pity my little teddy bear - "Zondick" - with his chest full of
Soviet space medals, couldn't have accompanied them. :-)

Pat