Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-L] [SPAM] Re: Comet ISON



Good point, but judging from the images shown in Sky & Telescope, as ISON
approaches the Sun it's near Mercury and Saturn in the sky, a bit below but
near the ecliptic plane, so not visible after sunset. Then, something I'd
missed in the article, the closest approach to the Sun is about Nov. 28, so
close that it may disintegrate due to extreme heating and tidal effects. If
it does emerge, the images shown for the first few days in December show it
moving nearly vertical, so definitely not visible after sunset.

Bruce


On Thu, Nov 14, 2013 at 2:41 PM, LaMontagne, Bob <RLAMONT@providence.edu>wrote:

Yes, you can see SOME comets in both the morning and evening. Remember,
not all comets orbit along the same plane that the planets do.

Imagine a VERY long pole extends outward along the rotation axis of the
sun - maybe about 10 sun diameters long. Place a flag on the pole on the
end that comes out of the sun's north pole. You will be able to see that
flag both in the morning and the evening because the long pole is
perpendicular to the path that the sun travels through the sky.

Bob at PC

-----Original Message-----
From: Phys-l [mailto:phys-l-bounces@phys-l.org] On Behalf Of Bruce
Sherwood
Sent: Thursday, November 14, 2013 1:47 PM
To: Phys-L@Phys-L.org
Cc: njaapt@mail.aapt.org
Subject: Re: [Phys-L] [SPAM] Re: Comet ISON

The latest issue of Sky & Telescope has diagrams of the situation for
ISON in
December, and the predictions are all about seeing things just before
dawn,
but their last image is for Dec. 5. The earthsky.org site shows an
evening
scene for Dec. 18, which might well be correct -- it would be after the
comet
has gone around the Sun, if it makes it around the Sun. What is
absolutely
certain is that you can't possibly see the comet both just before
sunrise and
just after sunset, on the same day.

Bruce
_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l