dipper@utastro.UUCP (Debbie Byrd) (10/23/84)
There are diamonds on the planet Venus. More on how they got there -- after this. October 23 Diamond Windows on Venus There are diamonds and sapphires on the surface of the planet Venus. We know -- because we put them there. These precious stones originally came from Earth. The diamonds and sapphires were used to make special windows in the Pioneer Venus planetary probes -- the first NASA craft to reach the surface of Venus in December of l978. In the last two decades spacecraft have revealed Venus to be a hellish world of intense heat and pressure. Its atmosphere is a hundred times denser than Earth's -- with a temperature of nearly 900 degrees Fahrenheit. The heavy clouds that completely cover Venus contain droplets of sulphuric acid. Probes to the Venusian surface must withstand incredible conditions of heat, pressure and corrosion. Several instruments on-board the Pioneer Venus probes needed windows -- windows thin enough to transmit light -- and thick enough to survive the descent to the planet's surface. Two windows made of sapphires were used for instruments recording information in the ultraviolet and visible wavelengths -- such as the spectrometer which measured the size of particles in the Venusian clouds. Other instruments on the Pioneer Venus probes viewed Venus though diamond windows. Diamonds are the only material that could withstand the high temperature and pressure -- and still transmit in the infrared. Thanks to information gathered by Pioneer Venus and other spacecraft missions -- we've begun to learn more about this planet so similar to Earth in size and density -- and yet whose surface is devastatingly different. Script by Diana Hadley. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin