🚀 go-pugleaf

The new Comet Halley -- after this.

October 21  Comet Halley

Comet Halley.  Its legacy to us is the Orionid meteor shower -- which
peaked this morning -- and the Eta Aquariid meteor shower in early
May.  This morning's shower was probably obliterated by bright
moonlight.  But today may be a good day to think again about Comet
Halley itself -- that "fuzzy blob" in the sky last winter and spring --
the most famous comet in history.

Some people enjoyed their view of Comet Halley -- and some were
disappointed.  But this comet was seen from space as well as from Earth
-- and spacecraft encounters with Halley revealed the comet as no one
had seen it before.

The very heart -- or nucleus -- of the comet was seen by spacecraft.
It measures about 10 miles long, five miles wide, and five miles high.
It looks very dark -- the nucleus reflects only about four percent of
the sunlight striking it.  Close up, the comet's nucleus looks like a
large lump with a smaller lump on one side.  It appears to be mostly
water-ice -- with a thin layer of some other material on its surface --
through which the comet's jets were seen to emerge.  The comet's
behavior earlier in this century made some scientists predict it would
have jets.  And so it does -- bright streams of material spewing from
the comet -- some appearing to originate in craters on the surface of
Halley.

A new finding about the comet is that it seems to be emitting radio
waves.  This result -- and others obtained by spacecraft from Europe,
the Soviet Union and Japan -- will have to be studied in more detail.
Meanwhile, NASA wants a more extended mission of its own to another
comet -- hopefully sometime in the 1990s.

Script by Deborah Byrd.
(c) Copyright 1985, 1986 McDonald Observatory, University of Texas at Austin