The Nashua River Watershed Association will hold its next Science Saturday for area youngsters from 1 to 2:30 p.m. Dec. 1 at the NRWA River Resource Center, 592 Main St. Children ages 7 to 11 will be able to learn about tje natural sciences in outdoor and indoor settings, and conduct experiments that connect to weather, rivers, forests, and wildlife. The fee is $25; preregistration is required. To register, contact Mary Marro at 978-448-0299 or e-mail marym@nashuariverwatershed.org .