[meteorite-list] Two Slow moving meteors over NE Pennsylvania

From: Sterling K. Webb <kelly_at_meteoritecentral.com>
Date: Fri Oct 1 02:18:11 2004
Message-ID: <415CF67D.4EE816C3_at_bhil.com>

Hi, All,

    Any object falling to Earth from a decaying orbit from East to West would be
in RETROGRADE orbit, which would be unusual for a man-made satellite. I don't
actually know if there are any retrograde satellites (help, experts!) but it's
hard to do, very expensive in deltaV, so I doubt it. A retrograde orbital
re-entry would be faster, not slower, than normal.
    A natural object captured by the Earth's gravity is equally likely to end up
in a retrograde or prograde orbit, even a partial one that brings it into the
atmosphere to burn up, but it wouldn't be slow in either case.
    An interesting possibility is an Inner Solar System object in an eccentric
orbit that extends out as far as the Earth. At the Earth, its (heliocentric)
velocity would be significantly less than the Earth's (heliocentric) velocity
and it could (if "ahead" of the Earth) be captured and enter the atmosphere at
far less than the Earth's escape velocity.
    This is about the only possible explanation of a slow moving retrograde
entry observation.

Sterling K. Webb
--------------------------------------------------------
"E. L. Jones" wrote:

> Any de-orbit/decay expected tonight Sep 30, 2004 over Eastern North America?
>
> Perhaps there is a swarm in orbit-- both fireballs were very similar in
> look and trajectory.
>
> Interesting greenish color, low incandescant fireballs tonight at 8:21
> and 8:27 Observed along Rt 209 in Carbon County Pennsylvania. They
> were slow moving, falling east to west. The first one glowed on two
> spots on the body itself after the fireball extinguished. This glow
> remained visible for almost as long as the fireball portion of flight.
> The observations were about 4-5 miles apart along the east west
> roadway. Didn't hear any sonic booms.
>
> (yeah ok ok I'll get around to a fireball report in time) I am
> announcing this now in the event that there is a stream and someone else
> gets to checkout their section of the sky.
>
> Regards,
> Elton
Received on Fri 01 Oct 2004 02:17:33 AM PDT