May's program is "Virtual Astronomy", presented by Hal Snyder. Hal is a scientific programmer at SageMath, Inc. His prior careers include math professor, physician, and software architect. Hal is also a library trustee and has been the Palatine city lead for the March for Science for three years. His talk will describe the use of open source tools, online data, and exploratory computing to improve one's understanding of astronomy. Examples include locally accurate eclipse & occultation timing, machine learning to study the Hertzsprung–Russell diagram, and the Laser Interferometer Gravitational-Wave Observatory’s ( LIGO) studies of gravitational waves.