Re: Re-entry over Melbourne Australia?

JRBURCA@aol.com
Fri, 15 Jan 1999 02:47:27 EST

Robin Whittle wrote:

<<  The object was a single point of bright bluish light - at least as
bright as Venus - and at first I thought it was a fast moving aircraft
or the search-light of the Police Helicopter at a lower altitude.  
It was travelling directly south to north.
It may have had some minimal kind of trail behind it - but not one
that persisted or that I can remember seeing.  It did not split up.
It retained its initial brightness (from when I first saw it) for a
second or so and then faded over the next one or two seconds.  The
final one or two seconds was obscured by trees.  It is very hard to
estimate time in situations like this!  >>

Hi Robin,

Your description sounds like a bright Iridium flare.  Someone could
research if there was one at that time at your location.  I don't have
time at the moment.  You can easily obtain a list of future bright
Iridium flares by going to the web site below.  All you need is your
correct latitude and longitude and UTC offset.

http://www.gsoc.dlr.de/satvis

Iridium flares have been the big new thing for satellite observers over
the last couple of years.  The phenomenon has been covered in Sky
and Telescope magazine and Astronomy magazine and other publications.
If memory serves, I think the site above will allow you to backtrack in time
to see if what you saw was an Iridium.  There are something like 72-80
Iridium satellites all in low polar orbits.  Each one has three antennas with
mirror-like surfaces.  These surfaces reflect bright sunlight and are as 
bright as Venus, some even brighter than Venus.  Some Iridium flares are
so bright that they can be seen in broad daylight for 1-2 sec.

Everything in your description conforms to what a bright Iridium flare would
look like:  as bright as Venus.....going N-S or S-N.....fades from peak 
brightness after you saw it....no trail (although seeing one for the first
time
unexpectedly it's easy to think one might imagine some "minimal" trail).....
the light might be perceived as bright blueish....and when this phenomenon
was first realized by some people, aircraft landing lights was one of the
first thoughts that came to mind.

Here are some other sites that should have links on Iridium flares:

http://www2.satellite.eu.org/satintro.html

specific page:
http://www.satellite.eu.org/iridium.html

http://users.skynet.be/sky56407/htmleng/iridium.htm

http://www.geocities.com/CapeCanaveral/Hangar/5990/iridium.html

A search engine should produce some good "Iridium satellite" results
I think. 

--  Jake Rees
    Burbank, California, USA