"Jim Wilkins" wrote in :

"Doug Miller" wrote in message
...
Ignoramus329 wrote in
:

On 2013-02-16, Jim Wilkins wrote:
Long period meteors that don't release water vapor trails like
comets
are hard to detect. We'd probably never notice one coming straight
at
us since it doesn't appear to move over time.

Scary and true!

It might be scary if it were true, but it's complete nonsense.

There is no such thing as "one coming straight at us" if for no
other reason than that we are
not sitting still. The direction from Earth to *anything* changes
continually, because we're in
an orbit about 190 million miles wide around the Sun. Anything
"coming straight at us" today
certainly won't be tomorrow, because the planet will have moved one
and a half million
miles.


If it approaches on a tangent from ahead or behind it won't have much
relative motion against the stars.

Maybe not immediately -- but just wait an hour or two.

What part of "one and a half million miles a day" are you having trouble understanding?