On Saturday July 31, 1999 the Lunar Prospector Spacecraft will be directed to impact near the south pole of the moon.   The impact is scheduled for 9:51 GMT (4:51AM for the Eastcoast of the US).  NASA is encouraging amateur astronomers to observe and record the event.  Dr. Tony Phillips, astronomer and science writer with the NASA Space Science News web site at NASA Marshall Space Flight Center, sent out the following message:

Scientists involved with the Lunar Prospector crash into the Moon are encouraging amateurs to observe the impact this Saturday morning, July 31 at 0951 UTC. Most professional astronomers will be using large telescopes with sensitive spectrometers to look for a tenuous cloud of water vapor. The vapor cloud will be invisible through typical amateur telescopes. However, amateur astronomers can contribute by watching for a impact plume that may be visible for up to several minutes after impact. Theoretical calculations suggest that the plume will likely be very dim and probably impossible to see so near to the sunlit edge of the full moon. Nevertheless there are many uncertainties in the physical models so scientists are urging amateurs to monitor the impact. Telescopes equipped with low-light astro-video recorders are considered best for scientifically useful observations, but still cameras and simple visual observations are also valuable. Details and observing tips for amateurs may be found at the Lunar Impact website All forms of data obtained by amateurs may be sent to Dr. Tony Phillips (FAX: 760-872-1382) who will forward them to the appropriate scientists at NASA/Ames and the University of Texas at Austin. We would particularly appreciate digital images and video sent to Tony Phillips as email attachments as soon as possible after the July 31st collision for posting on LunarImpact.com.