[meteorite-list] Rock on the ground or not?

[Lasse Lindh]

Hi Chris and Rob

Thanks for your replies. I can say with certainty that it was not a 
satellite. These are moving objects and I've seen plenty of those as 
well as iridium flares. I'm also an amateur astronomer and have seen my 
share of these man made objects. I've also seen a few meteors that 
almost took aim at me before, but slightly diverted, all fast and short 
ones. I could be mistaken on the time. It's hard to estimate time when 
things happen fast. It could well be a lot less instead. I have tried to 
go through the event in my head and the shortest time I've come up with 
is 5-6 sec but that feels a bit short. But it may be more correct.  It's 
based on the fact that the light caught my eye, I turned my head towards 
it and stared at it and concluded that it was out of place and should 
not be there. A second or two later it started to get weaker and 
disappeard. The weaening was gradual, not like turning a light bulb off. 
So it might be somewhere in the order of 5-7 sec.

Thing is, observing is quite easy but estimating time during an 
observation is a lot harder especially if all attention is concentrated 
towards the pure visual part.

The weather balloon theory sounds interesting. I've never seen anything 
like that. But then, it has to be very high to reflect the sun this time 
of the year an hour from midnight.


Regards

Lasse



Chris Peterson skrev:
> Hi Rob-
>
> It's certainly possible. I've seen three head-on meteors, and recorded 
> a few dozen on cameras. But I'm an astronomer, and spend a lot of time 
> looking.
>
> I don't know how accurate the 10-second time estimate was. If 
> accurate, it's not only too long for most meteors, but also a bit long 
> (but not impossibly) for an Iridium flare. More to the point, however, 
> is that Lasse was comparing the event location to surrounding stars. 
> Iridiums move pretty fast, and a 10-second flare would move 
> significantly. It sounds like he was enough in tune with the stars to 
> notice something like that.
>
> Another possibility, depending on the time and sun angle, would be a 
> reflection from a weather balloon (or its payload). I've seen them do 
> some pretty odd things, and they appear stationary for a long time.
>
> Chris
>
> *****************************************
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
>
>
> ----- Original Message ----- From: "Rob Matson" 
> <mojave_meteorites at cox.net>
> To: <meteorite-list at meteoritecentral.com>
> Sent: Sunday, March 30, 2008 7:15 PM
> Subject: Re: [meteorite-list] Rock on the ground or not?
>
>
> Hi Chris and Lasse,
>
> There is another possibility to consider:  Lasse may not have seen
> a fireball at all.  Consider:
>
> 1.  So-called "point meteors" are very rare; they are rarer still
> when the radiant is close to the observer's zenith.
>
> 2.  The 10-second duration is probably too long for a point meteor
> at such high elevation angle.  Even at the slowest possible initial
> entry velocity (11.2 km/sec), a meteor only 14 degrees from zenith
> cannot maintain a velocity above 3 km/sec for that length of time.
>
> I offer an alternate explanation:  Lasse may have observed a
> glinting satellite, perhaps an Iridium satellite.  This is easy
> enough to check, knowing the date, time and location of the
> observation.  On March 28th and 29th there were high elevation
> Iridium flares for Sweden in the early evening in the eastern
> sky -- in the vicinity of the bowl of the Big Dipper.  --Rob
>
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