[ My most popular posting ever, judging by the number of followups ]

From: kfl@access5.digex.net (Keith F. Lynch)
Newsgroups: rec.arts.sf.science,sci.astro,sci.physics,alt.folklore.science,rec.arts.sf.tv
Subject: TV Asteroid Science
Date: 16 Feb 1997 23:48:30 -0500

Here are the fundamental principles of asteroid science, as I learned
on NBC tonight:

* Asteroids travel through space making a noise like a powerful but
  subdued engine.

* Asteroids are usually locked into orbits, but if a comet comes by,
  they can be bumped out of their rut and become dangerously unstable.

* It's only the fact that everything is locked into an orbit which
  prevents collisions in our solar system.  Any asteroid that gets loose
  is certain to crash into Earth within a matter of hours.

* It's just barely possible to evacuate Kansas City to a distance of
  100 miles in 48 hours.  This requires lots of airplanes.  It also
  requires martial law, so that "looters will be arrested on sight".
  (Have they no mercy?)  With 30+ hours to go, people will panic in
  the streets and run around at random.

* A mile-wide asteroid can mostly burn up in the atmosphere, causing it
  to do only a relatively small amount of damage (bursting a dam) when
  it strikes.

* A river from a burst dam can exactly keep pace with a pickup truck for
  several minutes.  It will then obligingly pause as the pickup truck
  turns around and goes in another direction.

* When a raging river washes over a pickup truck on a bridge, the bridge
  won't be damaged, the truck won't be swept off the bridge, and people
  in the open back of the truck won't be swept away.

* A four-mile-wide nickel asteroid (which would mass about a *trillion*
  tons) can be destroyed -- literally destroyed, so that nothing remains
  -- by three airplane-mounted lasers.

* But with only two airplane-mounted lasers, it instead instantly
  explodes into thousands of pieces.  Astronomers are very surprised
  that it wasn't literally destroyed.

* Laser beams are easily visible in space.

* Incoming asteroids spend several minutes in Earth's atmosphere.

* Asteroids made of softer or more volatile stuff than nickel will
  harmlessly burn up in the atmposphere regardless of size.

* Asteroids that land in the ocean will do no damage regardless of size.

* Asteroids are discovered by astronomers peering directly through
  their telescopes in brightly lit observatories.  Whatever they see
  will appear on computer monitors, however.

* Asteroid positions are reported in plainly audible 75 BPS Baudot
  teletype signals.

* Oddly, there will be no dog to be rescued at the last possible moment.
  Maybe only tornadoes and volcanoes come equipped with dogs.  Would
  you settle for goldfish?

The stunning conclusion will be broadcast tomorrow night.  I look
forward to learning more TV asteroid science.