N.EO. 2010 KQ

http://www.nasa.gov/topics/solarsyst...d20100527.html

Can anyone explain to me the mechanism.?
Velecity of rocket part, relative to the earth , on path almost exactly
parallel to the earth's solar orbit path is enough to give one or more
solar-earth orbit path distance in 35 years?

On 03/06/10 10:39, N_Cook wrote:
http://www.nasa.gov/topics/solarsyst...d20100527.html
Can anyone explain to me the mechanism.?
Velecity of rocket part, relative to the earth , on path almost exactly
parallel to the earth's solar orbit path is enough to give one or more
solar-earth orbit path distance in 35 years?

I'm not really clear what you think the problem is? By
definition, the Earth is moving fast enough to complete one orbit
at one AU from the Sun in one year; so anything which is moving
at a comparable speed is also capable of completing an orbit in
something like a year. IOW, 2010KQ will return to roughly where
it was on May 27th [relative to the Sun] roughly every year, for
some value of "rough".

If it does so in *exactly* a year, then we will also be
there on May 27th, and there is a good chance of *ka-boom*. If
it's out by, say, a month, then after twelve orbits it will be
out by a year and again there is a decent chance of *ka-boom*.
If, as reported, its next near approach is in 2036, then the
implication is that it's out by about N/26 of a year, where N
is 1, 3, 5, 7, 9 or 11, ie roughly 2, 6, 10, 14, 18 or 22 weeks.

Note that the Earth's speed in orbit is 2 pi AU/year, so
a two-week error corresponds to a difference in speed of pi/13
AU/year, or about 1 km/s -- not much faster than Concorde, and
rather slow in terms of rockets and things in orbit. Of course,
this is an average over the orbit, and depends on the eccentricity
of the orbit; and a small difference in speed is not the same as
a small relative velocity. Details left as an exercise ....

After the 2036 approach, its orbit is likely to change,
perhaps quite dramatically if the approach is very near [eg, sub-
lunar]; so the following near approach is likely to be after
some different number of years, up or down. But it will continue
to be an occasional visitor until either it hits us or it passes
close to some other planet [and changes orbit] or, if it survives
long enough, perturbations from [eg] Jupiter affect it enough to
shift its orbit well away from ours.

--
Andy Walker
Nottingham

Andy Walker wrote in message
news:z_LNn.1191$jL2.1125@hurricane...
On 03/06/10 10:39, N_Cook wrote:
http://www.nasa.gov/topics/solarsyst...d20100527.html
Can anyone explain to me the mechanism.?
Velecity of rocket part, relative to the earth , on path almost exactly
parallel to the earth's solar orbit path is enough to give one or more
solar-earth orbit path distance in 35 years?

I'm not really clear what you think the problem is? By
definition, the Earth is moving fast enough to complete one orbit
at one AU from the Sun in one year; so anything which is moving
at a comparable speed is also capable of completing an orbit in
something like a year. IOW, 2010KQ will return to roughly where
it was on May 27th [relative to the Sun] roughly every year, for
some value of "rough".

If it does so in *exactly* a year, then we will also be
there on May 27th, and there is a good chance of *ka-boom*. If
it's out by, say, a month, then after twelve orbits it will be
out by a year and again there is a decent chance of *ka-boom*.
If, as reported, its next near approach is in 2036, then the
implication is that it's out by about N/26 of a year, where N
is 1, 3, 5, 7, 9 or 11, ie roughly 2, 6, 10, 14, 18 or 22 weeks.

Note that the Earth's speed in orbit is 2 pi AU/year, so
a two-week error corresponds to a difference in speed of pi/13
AU/year, or about 1 km/s -- not much faster than Concorde, and
rather slow in terms of rockets and things in orbit. Of course,
this is an average over the orbit, and depends on the eccentricity
of the orbit; and a small difference in speed is not the same as
a small relative velocity. Details left as an exercise ....

After the 2036 approach, its orbit is likely to change,
perhaps quite dramatically if the approach is very near [eg, sub-
lunar]; so the following near approach is likely to be after
some different number of years, up or down. But it will continue
to be an occasional visitor until either it hits us or it passes
close to some other planet [and changes orbit] or, if it survives
long enough, perturbations from [eg] Jupiter affect it enough to
shift its orbit well away from ours.

--
Andy Walker
Nottingham


So someone arranges for something quite massive and velocity enough to leave
earth's gravity and in a direction near enough exactly parallel to the
tangent of the earth's orbit. Knowing that a few decades later it will have
travelled AU*2*Pi to likely hit the earth at much the same relative speed.
That sounds like gross incompetence to me

On 03/06/10 12:47, N_Cook wrote:
So someone arranges for something quite massive and velocity enough to leave
earth's gravity and in a direction near enough exactly parallel to the
tangent of the earth's orbit.

Actually, to judge from the diagram on the page you referred
to, it came in at a reasonable angle and went out roughly parallel;
tho' there isn't really enough information there to be sure. But no
matter. ...

Knowing that a few decades later it will have
travelled AU*2*Pi to likely hit the earth at much the same relative speed.
That sounds like gross incompetence to me

... Well, it's a feature of closed orbits in a two-body [eg
Sun/planet or Sun/spacecraft] system that the bodies keep coming back
to the same point with the same velocities. Any changes are due to
perturbations, from [eg] Jupiter and/or from near-encounters with
[eg] Earth. So it's not so much incompetence as inevitable, unless
the spacecraft can either be aimed at some other planet on launch or
retain enough fuel to be steered off when well away from Earth.

It's not going to matter to us, anyway. Whether 2010 KQ is a
stray spacecraft or a genuine asteroid, it's too small to survive its
trip through our atmosphere and do serious damage on the ground.

--
Andy Walker
Nottingham