HMNS hosts a variety of events and attractions celebrating Earth this month, including GAIA by Luke Jerram, a 23-foot diameter sculpture in the Grand Hall (on display from April 18-28); City Nature Challenge, which invites the community to record observances of plants, animals, or fungi (submit observations between April 24-27); and fun events such as Plant Bingo (April 2, 10, 17, and 24, 11 a.m. and 1 p.m., for 18+); Hummingbird Feeder (April 8-9, 1:30-3 p.m.); and Bookmark Planting Station (April 13-14, 10 a.m.-12 p.m.). See www.hmns.org/celebration-earth.