(meteorobs) Fireball or Comet?

[Lew.Gramer at noaa.gov]

Al, I believe your friend captured some nice images of a pre-sunrise contrail - a condensation trail formed by ice that condenses around jet engine exhaust, in the middle atmosphere.

I can say it's very likely a contrail for four reasons: first, contrails are just far more common than the other alternatives, which would be a very bright fireball or satellite reentry. Second, this actually appears to get BRIGHTER as the sun comes up - not what you would expect from an ion trail, though a debris trail (which reflects light, rather than glowing) might show this feature. Third, it remains visible against the cirrus in the background, which even the debris trail of a massive fireball would not. And finally, it sounds as though the object actually took minutes - rather than seconds - to reach its full length. Hence it was traveling too slowly to be a fireball, or even a normal re-entry.

That said, of course, you never know! Without an experienced visual observer there to confirm what Mr. Roberts recorded, it would require a detailed review of the photos (probably from the originals) by someone with more experience analyzing images of fireballs and/or reentries than yours truly.

Clear skies!
Lew Gramer


----- Original Message -----
From: Al Degutis <al.degutis at gmail.com>
Date: Tuesday, October 23, 2007 7:24 am
Subject: (meteorobs) Fireball or Comet?

> A reader sent me the following via e-mail:
> 
> ================================================
> Fireball or Comet?
> 
> I went outside and and i noticed a huge streak in the western sky
> around 6:30pm, it had a huge head at first, i ran inside to get my cam
> and got back outside and noticed the head was smaller. Realized no
> battery in cam so i went to get battery then by this time the head was
> smaller again and now it was going down behind a house and couldn't
> get a shot so i got in my car and drove to a nearby lake and captured
> a few photos. I'm not sure what it was. Time span from first photo to
> the last was about 15 mins or so. Images taken with a canon digital
> rebel 350D with a 75mm to 300mm canon lens at full zoom, second pic
> was cropped.
> 
> Images were taken from Newfoundland, Canada by Eddie Roberts on Oct 22
> ================================================
> 
> I've uploaded his pictures here:
> http://www.skyinsight.com/gallery/v/eddieroberts/
> 
> -- 
> Al Degutis
> Editor-in-Chief
> AstroPhoto Insight Magazine
> http://www.astrophotoinsight.com
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