UFO UpDates Mailing List
From: Donald Ledger <dledger@ns.sympatico.ca> Date: Sat, 10 Apr 1999 10:10:46 -0300 Fwd Date: Sat, 10 Apr 1999 15:48:50 -0400 Subject: Re: Were Arnold UFOs Fireballs? >From: Bob Young <YoungBob2@aol.com> >Date: Thu, 8 Apr 1999 23:52:56 EDT >Subject: Re: Were Arnold UFOs Fireballs? >To: updates@globalserve.net >>From: Donald Ledger <dledger@ns.sympatico.ca> >>Date: Thu, 08 Apr 1999 20:40:47 -0300 >>Fwd Date: Thu, 08 Apr 1999 21:04:04 -0400 >>Subject: Re: Were Arnold UFOs Fireballs? ><snip> >>With an approximate time of 2.5 to 4 seconds from top of >>atmosphere to ground level for a meteor's travel, how can anyone >>in that field even consider meteors? How does something like >>this get in a SETI journal? >Hi, Don: >Where did you got these numbers? A meteor begins to glow about >115 kms until about 50 kms, and if it is large enough then drops >at free fall to the Earth's surface. Larger meteoroids can >continue to glow to lower altitudes that small ones. Meteoroid >speeds upon _entering_ the atmosphere range from 11 to 74 >kms/sec depending upon whether the Earth catches up to the >meteoroid in its orbit or it hits us head on. >So, 2.5 to 4 seconds might be a good length of time for some >visible meteors, others have a longer "dark" flight. Also, the >hypothesis obviously refers to a meteor travelling in a near >horizontal path. A bright, widely photographed fireball like >this back in the early 1970s is known to have had a zenith to >horizon time of 1 minute. >Also, it is now believed that very bright meteor fireballs of >this type are not related to meteor showers, believed to come >from comets, but have their origins in the asteroid belt as >rocky objects. >Clear skies, >Bob Young Hi Bob, I picked a number right in the middle for the sake of argument 46 kps or 28 mps. I used 60 miles for the approx. top of the atmosphere where you are using about 70 miles. I ignored bolides they because they slice through the upper atmosphere at about 60 miles or so; much higher than Arnold's objects at 6-7,000 feet. In any event for the writer of the original article, to attribute Arnold's sighting to meteors was amatuerish and uninformed at best. Don
UFO UpDates - Toronto -
updates@globalserve.net
Operated by Errol Bruce-Knapp - ++ 416-696-0304
A Hand-Operated E-Mail Subscription Service for the Study of UFO Related
Phenomena.
To subscribe please send your first and last name to
updates@globalserve.net
Message submissions should be sent to the same address.
|
Link it to the appropriate Ufologist or UFO Topic page. |
Archived as a public service by Area 51 Research Center which is not
responsible for content.
Financial support for this web server is provided by the
Research Center Catalog.
Software by Glenn Campbell.
Technical contact:
webmaster@ufomind.com