dipper@utastro.UUCP (Debbie Byrd) (12/14/84)
The first spacecraft to reach the vicinity of another planet arrived on this date in 1962. More on Mariner 2 at Venus -- in just a minute. December 14 Mariner Two The first spacecraft from Earth to sweep past another world did so on today's date in the year 1962. That other world was Venus -- and the craft was Mariner 2. Mariner 2 was launched in late August of 1962 and took 109 days to travel to Venus. It sailed past the planet at a distance of about 20 thousand miles, and provided about half an hour of scanning by scientific instruments. As it peered down at the unbroken clouds of Venus, the spacecraft saw that they contained no water vapour. It also discovered, among other things, that the surface of Venus is incredibly hot. It's now known that Venus at its surface is hot enough to melt lead, with temperatures ranging up to about 900 degrees Fahrenheit. Mariner 2 is still in orbit around the sun. It still approaches the orbit of Venus every few hundred days -- but when it gets there, Venus is almost always in a different part of its orbit. After hundreds of thousands of years, it's possible that Mariner 2 will once again encounter Venus. The gravity of Venus may at that time accelerate the craft into a completely different orbit -- so that the first spacecraft ever to visit another world will eventually fall into the sun -- or be swept up by one of the planets -- or be ejected altogether from the realm of the solar system. By the way, tomorrow is the anniversary of the first spacecraft to LAND on Venus. Tune in tomorrow -- and we'll tell you about it. Script by Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin