[Launch Alert] Launch Yesterday?

[Brian Webb]

                             LAUNCH ALERT
 				  
                             Brian Webb
                     Ventura County, California
                         kd6nrp at earthlink.net
                     http://www.spacearchive.info
		       
                                 2010 January 1 (Friday) 17:02 PST
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                           LAUNCH YESTERDAY?

There have been reports and photos of a California December 31 dusk
rocket or missile launch. There was no launch from Vandenberg
yesterday.

I receive a small number of such reports each year and they are worth
discussing.

First, ALL launches from Vandenberg AFB are announced in advance by
the Air Force and in Launch Alert. That said, Vandenberg isn't the
only place where rockets and missiles are launched along the
California coast. In the past, missiles have been launched from Navy
ships and submarines offshore, from Air Force cargo planes, and San
from Nicolas Island. So it's within the realm of probability (but
that you may spot a launch even though there is nothing scheduled from
Vandenberg.

It's more likely that what people saw was one of the numerous jet
contrails that cross the sky this time of year. I believe that in this
part of the world contrails occur in a portion of the atmosphere some
5,000 feet thick called the "contrail zone".

This zone has a mean altitude of 33,000-38,000 feet. The height of
the zone varies with the time of year. During the summer, it's higher
than where most passenger jets fly. However, during the winter, the
contrail zone is much lower and coincides with the crusing altitude of
many jets fly.

Depending on your point of view, a jet contrail may appear to be
steeply inclined when in fact it's level.

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