(meteorobs) Could the NE US fireball have even POTENTIALLY been a Lyrid?
mameteors at yahoo.com
Mon Apr 25 15:55:42 EDT 2005
The question has arisen in the press, whether the recent very bright fireball
seen over the Northeastern United States could potentially be a Lyrid.
I'm Florida right now, so collecting data is a bit tricky. But as I understand
it, the fireball was reported as being seen well before the local radiant-rise
time of the Lyrids for that region. However, some people have suggested that
this could be discounted, if the meteoroid had traveled a "wrapped" trajectory
after beginning its initial atmospheric entry... So it COULD still be a LYR.
My initial answer to this possibility would be "definitely no" - a meteoroid
traveling at the V_inf of the Lyrids (49 km/s) would have to endure incredible
torques to be "wrapped" in the way you're envisioning - and in any case, the
gravitational shift in its trajectory would only be that significant once the
body had lost most of its celestial velocity, and so was no longer traveling at
a sufficient velocity to be visible from the ground.
On the other hand, some very bright fireballs have exhibited incredibly long
in-atmosphere trajectories in the past - albeit those that I can think of all
had smaller initial V_inf than a Lyrids would, and were considerably denser
(say 3+ gm/cm3) than a Lyrid meteoroid is likely to be (say 0.4 to 0.8 gm/cm3).
However, as a pure amateur, I would not rely on my own opinion about this, when
speaking with the press! So I am posting this to 'meteorobs' now, in hopes that
some of our readers will have the experience and the knowledge to say for sure
whether the Lyrids are even a possible source for the event, according to the
data collected from witnesses so far.
So, Peter, Peter, Colin, Rob, Sergey, and our many other experts: how about it?
Clear skies to all!
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