dipper@utastro.UUCP (Debbie Byrd) (05/09/85)
The planet Venus is now at its brightest in the predawn sky. More -- after this. May 9 Venus at Greatest Brilliancy If you're up before dawn, and you look toward the east, it'll be hard NOT to notice an incredibly bright object low in the eastern sky. It's the planet Venus -- at greatest brilliancy today -- as bright as it'll be for the rest of this year. Early last month, Venus passed in between the Earth and sun -- and, as result, we saw the planet move from our evening sky to the sky visible before dawn. Venus is now ahead of Earth in the race of the planets around the sun. Most of its sunlit side faces away from our direction in space -- so that, if you could see Venus now through a telescope, it'd look like a smaller, featureless version of the crescent moon. This crescent Venus now shines more brightly than the fuller Venus we see at other times. Greatest brilliancy for the planet Venus results from a kind of trade-off between the thickness of the crescent turned toward our direction -- and the distance between us and Venus. Later on, the crescent will be fuller -- but Venus will be farther away -- and so it won't look as bright. We're traveling behind Venus in orbit now -- due to fall farther and farther behind, since Venus moves faster than Earth around the sun. As a result, we'll see Venus climb a little higher up in the east before dawn -- then stay in pretty much the same spot until next fall -- as in reality this world speeds ahead of Earth in orbit -- and so appears to us to fade in brightness. Script by Deborah Byrd. (c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin