Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site amdahl.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!whuxlm!harpo!decvax!decwrl!sun!amdahl!canopus From: canopus@amdahl.UUCP (Alpha Carinae) Newsgroups: net.aviation,net.astro Subject: Re: Something else to watch out for! Message-ID: <1679@amdahl.UUCP> Date: Mon, 17-Jun-85 13:33:49 EDT Article-I.D.: amdahl.1679 Posted: Mon Jun 17 13:33:49 1985 Date-Received: Wed, 19-Jun-85 03:11:34 EDT References: <11270@brl-tgr.ARPA> <1199@phoenix.UUCP> Distribution: net Organization: RA: 6h 22m 30s; Dec: -52d 36m Lines: 50 Xref: watmath net.aviation:1642 net.astro:676 > > Anyway, this JAL flight was cruising at some normal jet-type altitude > > (like 30,000 ft or thereabouts) some distance above a rather dense cloud > > layer. Suddenly, directly ahead, the pilot saw the clouds begin to rise up > > in an enormous bulge. The cloud bulge grew at fantastic speed, and > > soon reached up and sideways for distances measureable in miles. > > [...] > > > > What caused this? Well, the theory is that that airplane had the first > > observed encounter with a meteor. [...] > I can't imagine how hitting a cloud layer - no matter how > dense - would be like hitting the ground (even at meteoric speeds). > Supersonic aircraft, space-shuttles etc fly regularly through > dense clouds without a bump. 1. Keep in mind that supersonic aircraft, space shuttles and the like are built and designed to slice through air at supersonic speeds. Also keep in mind that even the shuttle, which impacts the atmosphere during reentry at something approaching 5 miles a second would surely burn up without its special heat shield tiles. 2. Meteors generally impact our atmosphere at speeds exceeding 30 miles a second, and are hardly aerodynamically stable! Most are sand grain to pea sized pieces of stone, and vaporize within a second or two, usually at distances above 60 miles from the ground. Occasionally, a bigger (softball sized or larger) meteor impacts the atmosphere, and explodes in a brilliant flash. These are often called "bolides". I do not know if the observed cloud was due to a meteor explosion; if it were I would suspect that the pilot should also have seen the explosion which preceded it. > As a skydiver I've fallen through > dense clouds without feeling a thing (although I've often wished > they really were like soft fluffy cotton wool :-) ) Sure. You're only falling at around 120 mph or so. I guarantee that if you accelerated to 15,000 mph you'd feel it. > Made in New Zealand --> Brent Callaghan -- Frank Dibbell (408-746-6493) ...!{ihnp4,cbosgd,sun}!amdahl!canopus Amdahl Corporation, Sunnyvale CA [This is the obligatory disclaimer..] - - - - - - - - - - - - - - - - - - - - - - - "I call it 'tranya'. I hope you relish it as much as I."