The whole family can enjoy an evening of science, engineering, astronomy, arts, crafts and games. Vendors will provide interactive activities. Sponsored by Howard Astronomical League and Howard County Recreation and Parks. Preregistration encouraged but not required. $5 per person. 6:30-9:30 p.m. Alpha Ridge Observatory, Alpha Ridge Community Park, 11685 Old Frederick Road, West Friendship. 410-313-4634.