dipper@utastro.UUCP (Debbie Byrd) (10/08/84)
The planet Venus spins very slowly -- and backwards compared to most other planets. More about Venus -- right after this. October 8 Venus in the West The brightest star in the sky after sunset is really a planet -- Venus -- now easy to see low in the southwest. Monday night Venus is near another planet, Saturn -- the second-brightest object in that part of the sky. During the day on Monday, Venus passes due southward from Saturn on the dome of the sky. Saturn is now about to disappear into the sun's glare -- while Venus is going to appear higher in the west each evening. Venus appears brilliant and beautiful in our sky -- it's bright mainly because its thick clouds are good at reflecting sunlight. Venus is also nearby -- it's the planet just inward from Earth. This world is similar to Earth in size and density. But its blanket of clouds hides a surface very different from that on Earth -- a place where surface pressure is 100 times greater than here -- and where surface temperatures range up to 900 degrees Fahrenheit. What's more, Venus spins on its axis backwards compared to most other planets and moons. And it spins very slowly. While Earth completes a single spin on its axis in about 24 hours, Venus takes more than 200 days to spin around once. No one knows what may have caused Venus to have this slow, backwards spin. But there've been many speculations -- like this one. Suppose Venus once had a moon, whose orbit decayed -- and which ultimately crashed into the planet. The collision could have caused the strange rotation of Venus. But if so, evidence of this lost moon remains to be discovered. Script by Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin