[net.astro] StarDate: December 22 Jupiter and the Moon

dipper@utastro.UUCP (Debbie Byrd) (12/22/84)

The moon is new today -- and near Jupiter in the west tomorrow.  More
-- right after this.

December 22  Jupiter and the Moon

Earth's moon takes about a month to orbit our world once -- so once
each month the moon comes in between the Earth and sun.  Then the moon
is said to be new -- and it's invisible in our sky -- hidden in the
sun's glare.

Well, that's the situation today.  The moon is new today -- between the
Earth and sun -- and so impossible to see from the surface of the
Earth.  But by tomorrow the moon will have edged away from that
imaginary line between the Earth and sun.  Moving eastward in orbit as
it always does, the moon will appear slightly east of the sun -- which
translates to mean it'll be low in the western sky shortly after the
sun goes down.  The sunlit half of the moon will face mostly away from
our world -- so tomorrow after sunset, we'll see the moon as a slim
crescent.

It so happens that this slim crescent moon is near a planet tomorrow
evening -- Jupiter -- which has been visible in our sky throughout the
past year.  Now Jupiter is going the opposite way from the moon in our
sky.  As the moon appears a little higher in the west each evening,
Jupiter is sinking down into the sun's glare.  It'll be gone from our
evening sky entirely shortly after the first of the year -- only to
return to the sky visible before dawn around the end of January.

So take a look outside Sunday evening shortly after sunset.  In the
west, you'll find a slim crescent moon -- near the giant planet
Jupiter.


Script by Deborah Byrd.



(c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin