dipper@utastro.UUCP (Debbie Byrd) (04/03/85)
Today, Earth, Venus and Mercury are neck-in-neck in the race around the sun. More -- after this. April 3 Earth, Venus and Mercury The planets Mercury and Venus orbit the sun inward from Earth. So these two worlds move faster than Earth in orbit -- since the closer a planet is to the sun, the faster it travels around it. Recently, both Mercury and Venus have been catching up to Earth in orbit -- about to gain a lap on us in the race around the sun -- or pass between the Earth and sun on the inside track. As they steadily gained on our world, we saw Mercury and Venus sink toward the sun in the western twilight sky each evening. Each day they came closer to that Earth/sun line -- and finally disappeared in the sun's glare. That's where they are still -- hidden in the glare of the sun. Today Mercury, Venus and the Earth are neck-in-neck in their respective orbits -- with Mercury slightly in the lead -- crossing that line between the Earth and sun just eight hours ahead of Venus. True to the speedy god Mercury for which it was named, the planet Mercury will continue to pull ahead of Venus and the Earth -- to win as always in this leg of the race around the sun. But the extreme brightness of Venus -- and the geometry of worlds in orbit as seen from Earth -- will cause Venus to show up in the east before dawn before Mercury does. Start looking for Venus a week or so from now -- low in the east before the sun comes up. Mercury will become visible in that part of the sky too -- by the end of the month. Script by Deborah Byrd. (c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin