dipper@utastro.UUCP (Debbie Byrd) (08/06/84)
The moon you see in the afternoon this week is waxing toward full. More about seeing the moon in daytime -- after this. August 6 Between First Quarter and Full You can see the moon in daylight this week. It's not an uncommon sight -- the moon is often visible in the daytime -- if you know where to look. Last Friday night the moon was at first quarter -- where it looked like a lighted half-circle in our sky. The moon at first quarter is ninety degrees from the sun on the dome of the sky -- that's one quarter of the moon's orbit around Earth -- or one quarter of a full circle. But because we only see half the sky at any given time above our horizon, the moon at first quarter is halfway across the sky from the sun at sunset. This evening and until next Saturday, the moon you'll see is called gibbous -- it's waxing towards full. The moon is now moving in its orbit towards the side of the Earth opposite the sun -- and when it gets directly opposite the sun from Earth, the moon look to us to be full. As the moon waxes from first quarter to full, we see more and more of the half of the moon that's illuminated by the sun. So in the next day or two, if you're outside in the late afternoon -- glance eastwards and -- in a cloudless sky -- you'll easily spot the moon. Each afternoon before sunset this week the moon will appear closer to the eastern horizon. Finally, this coming Saturday, the moon will be full -- and it'll rise in the east just as the sun is going down. Script by Diana Hadley and Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin