Date:         Fri, 17 Jan 2003 17:04:10 -0700
Reply-To:     Bill N <freeholder@STARBAND.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Bill N <freeholder@STARBAND.NET>
Subject:      Re: Friday - hazards to our van (LVC)
Content-Type: text/plain; charset="iso-8859-1"

Well, since I teach Astronomy at our local college, I guess I should chime in on this.  Meteors
have an initial speed relative to the Earth of 10 to 60 miles per second -- yes, per second.
This meteor was at the bottom of that scale initially.  In addition, it hit at a very shallow
angle.  Instead of coming straight down, it was going sideways, and passed through several
hundred miles of atmosphere before finally falling to earth.  If it had come straight down, it
would have caused a LOT more damage.  The damage done by meteors is not comparable directly to
a bullet.  All of the energy of motion of a meteor is converted to heat at the moment of
impact.  The result is an explosion and frequently a crater.  The fact that this particular
meteor was moving almost sideways instead of coming straight down meant that most of the energy
of motion was converted into heat in the atmosphere instead of upon impact.  Thus the
"fireball" visible over a course of several hundred miles.

Oh, and the bullet from a common hunting rifle, like a 30.06, leaves the muzzle traveling at a
bit over 3000 feet per second, which is pretty close to 2000 MPH.  Even a "slow" meteor
traveling at 10 miles per second is going 25 times faster than that when it enters the
atmosphere.  Handgun bullets are, of course, slower, moving as slow as 600 FPS up to about 1500
FPS.  A few "hot" varmit cartridges, like the .222, may have an initial velocity of 4000 FPS,
which is still way slower than meteors.  Luckily, the atmosphere does a fairly good job of
protecting us.  Unfortunately, it does almost no good against a large one.  Atmospheric slowing
of a 500' meteor is pretty nil.

Now, will a Tiico conversion allow me to run with the meteors, or should I go for a Subbie 6?

Bill Nolan

----- Original Message -----
From: "Bill Kasper" <dragonlist@IPMTS.UCSC.EDU>

>
> which means it's about 2000 mph, so much faster than a bullet from most
> guns, right?  and, the fact that it was going through something
> relatively rigid (that deforms plastic prior to rupture), and you've
> got a puncture much more than an "explosion".
>
> bill
>
>
> On Friday, January 17, 2003, at 02:05 PM, Kim Brennan wrote:
>
> > It was well documented and wasn't a hoax. Typical meteor speeds are
> > "only" 2x 3x speed of sound (comets hit at a much faster speed and act
> > as if there was no atmosphere.)
> >
> > On Friday, January 17, 2003, at 04:32  PM, developtrust wrote:
> >
> >> I just still do not believe a meteor will slow down enough to cause
> >> such
> >> minor damage. It has to be a hoax.
> >
>
>