Expert: Tom Whiting - 5/28/2009

Question
Wednesday, May 27, 2009 around 9:45 p.m. I was in my backyard and noticed a very bright white light in the sky.  A steady, not flashing, round white ball of light moving very slowly away from me that gradually decreased in brightness and size until it was gone.  When I say gradually - we are talking minutes not seconds.  There were many planes in the sky, all of which, paled in brightness and size to this light.  I have seen shooting stars before, but this light did not leave any type of trail, moved at a slower pace and was much brighter than any I have ever seen in my lifetime It was very odd.  Any idea what it could be and have there been any other reported sightings?  I live in Newark, Delaware.

Answer
Hi Tracey,
Meteors come in many varieties and many forms, from directly
head on point sources of light lasting from 1 - 30 seconds long,
to long slow paths across the sky lasting from a few seconds to
nearly a minute long...especially if they come from a westward
direction (to an eastward direction) in the same direction of the Earth's rotation.  Typical entry speeds are from 1 - 100 miles per
second, but on occasion, a west to east meteor may have an entry
speed of only 0.01 mile per second, so the meteor can last nearly
a minute at that very slow speed relative to the Earth.
Some leave residual trails (ionized air molecules) from just a few
seconds to minutes long; But most don't leave any residual trail at all.
Most all of them burn up, from 60-100 miles high...only the very large ones (say baseball size or larger) can make it down low enough to either explode and/or produce a sound and/or strike the ground.


I am nearly certain that that is what you saw, a very slow mover,
a fairly rare event...as in 50 years, I've only seen one like that myself.  Generally those have a very flat entry angle relative to
the top of the atmosphere, and it MAY have even skipped off the
top of the atmosphere and actually skipped back into space, as that
can happen too....there's no way to tell whether it just disintegrated or skipped back into space.

I'm glad you used the term meteor...instead of falling or shooting
star...as they are mostly grain of sand size...space junk...and
have nothing to do with the stars.  (A marble-sized meteoroid will
make a fairly bright meteor).  Oh, they are meteoroids before they
hit the atmosphere, meteors while giving off light and heat, and
if it hit's the Earth's surface, then it becomes a meteorite.

AS far as other sightings of same object, you can either research it on the internet, or check your local newspaper and TV stations...people making sightings like that generally call their local TV station or sometimes even the local police....I don't know why.  Generally there is not much interest for us astronomers unless
the object most assuredly hits the ground, and is recoverable.
Then it's quite a rare and valuable object.

Clear Skies,
Tom Whiting
Erie, PA