On Sunday, December 10, 2017 at 1:43:22 PM UTC-8, Mark Earnest wrote:
On Sunday, December 10, 2017 at 2:44:21 PM UTC-6, Hägar wrote:
"Herbert Glazier" wrote in message


Most have one tail.Some have two,and some no tail at all.Some tails are a
million miles long(WOW) What are these tails made off? I think dust??? Some
say water.Is the sun not only reflecting light of these dusty tails,but also
creating them? Photons from sun do effect the direction of tails when comet
swings around the sun. Is it possible comets leaving the Oort cloud have no
tails,and tails come to be when comet enters the solar system? I saw Halley
comet when I was 5 or 6 Many moons ago.Treb&bert


*** you are one clueless dummy, treBert. By the time comets are
visible to the naked eye, they have two tails.
One trails in the direction of travel and the other is blown in the
direction of the Solar Wind, pointing away from the Sun.
Sunlight heats the comet's ice and when it vaporizes into steam
it carries dust particles with it, which then form both tails.


Solar heat cannot be vaporizing comets or comets would quickly not be there any more. We need to all take a trip to a comet some day to find out what the tail is made of. Don't think you know before you find out!