ITHACA, N.Y. -- Richard N. Zare, the Marguerite Blake Wilbur Professor of Chemistry at Stanford University, will give the Harry S. Kieval Lecture In Physics at Cornell University on Monday, March 31. The lecture, "Laboratory Measurements of Extraterrestrial Visitors," will begin at 4:30 p.m. in Schwartz Auditorium, Rockefeller Hall. Refreshments will be available from 4 to 4:20 p.m. in the first floor hallway. Zare, chairman of the National Science Board and a member of the National Academy of Sciences, was a member of the research group that reported last year that a Martian meteorite contains fossilized evidence of microbial life. Zare's chemistry laboratory provided the technique, called laser mass spectrometry, for analyzing the meteorite.