Every Fri., except Aug. 14. All invited to drop in to use the observatory’s 1857 Fitz telescope and other modern instruments. Exhibits are also open regardless of viewing conditions. Last visitors admitted 30 minutes prior to closing. 9–11 p.m., 1398 E. Ann at Observatory. Free, no registration required. (734) 763–2230, detroitobservatory.umich.edu.

Every Sat., Mon., & Thurs. (different AARC locations). Runners of all abilities invited to join either a beginner or advanced group run (Sat.) or a 5K mapped route (Thurs. & Mon.). AARC Traver Village (7 a.m. Sat.), 901 W. Eisenhower; Corner Brewery (6 p.m. Mon.), 720 Norris, Ypsi; and AARC Colonnade (6 p.m. Thurs.), 2621 Plymouth Rd. Free. annarborrunningcompany.com.  

Every Sat. Moderate-paced ride, 20 miles or more, to Dexter and beyond. Pack something to eat or stop in Dexter or Chelsea for coffee or breakfast. Note: Riders should be prepared to take care of themselves on all AABTS rides. Carry a water bottle, a spare tire or tube, a pump, a cell phone, and snacks. See aabts.org for weather cancelations or delays. 8 a.m. sharp, meet at Barton Nature Area parking lot, W. Huron River Dr. near Bird. Free. (734) 649–9762, [email protected].

Every Sat. All invited to join a timed but noncompetitive 5K run/walk. 8 a.m., Lillie Park South, 4365 Platt. Free, but first-timers are requested to preregister at parkrun.us/lillie and arrive at 7:45 a.m. [email protected].

Runners and walkers of all ages invited to follow a 3-mile route through downtown on a scavenger hunt. 9 a.m., 123 E. Liberty. Free, preregistration required at tinyurl.com/a2fleetscav. (734) 929–9022.

Aug. 8, 15, 26, & 29. Chamber music performances by small groups of A2SO musicians. Dexter Farmers’ Market (Aug. 8, 10–11:30 a.m.), 3233 Alpine, Dexter. Ypsilanti Farmers Market (Aug. 15 & Aug. 29, 10–11:30 a.m.), 16 S. Washington, Ypsi. Saline Farmers Market (Aug. 15 & 29, 10–11:30 a.m.), 104 S. Ann Arbor St. #4, Saline. Ann Arbor Farmers Market (Aug. 26, 10–11:30 a.m.), Farmers Market Pavilion, Kerrytown. Various times and locations. Free. (734) 994–4801, a2so.org/farmers-markets.

Every Sat., Fri., & Wed. All invited to play one of 200 songs, with melodies transcribed in numbers, on the 17-bell chime’s numbered keys. Ambitious players can add chords. Kids welcome. 10:30–11 a.m. (Sat.) & noon–12:30 p.m. (Wed. & Fri.). Free. [email protected].

Artists with work in Cluster’s current show, Hands in Action (see Galleries) discuss their work, flow, studio practices, and personal revelations that arise through making art. 11 a.m., 307 N. Main. Free. clustermuseum.org/events.

This month’s meeting canceled.

All invited to join this group of sketchers who meet to sketch and share what they’ve done. 11 a.m.–1 p.m., location TBA on facebook.com/groups/uskannarbor. Free. urbansketchersannarbor.com.

Every Tues.–Sun. All age 6 & up invited into the museum’s labs to use scientific tools and museum specimens. The newest program lets participants try out simulated snake senses to experience the world as if they were a snake. No live snakes. 11 a.m.–3 p.m., 1105 North University. Free. (734) 764–0478, ummnh.org.

Aug. 8, 15, & 22 (different times). Docent-led tours exploring ancient Greek and Roman demi-gods in “Centaurs and Sirens and Satyrs, Oh My!” (Aug. 8), ancient female images in “Women in the Kelsey” (Aug. 15), “Daily Life in Ancient Rome” (Aug. 22, 11:15 a.m.), and “All That Sparkles: Egyptian Jewelry” (Aug. 22, 2 p.m.). 11:15 a.m.–noon (Aug. 8 & 22) & 2–3 p.m. (Aug. 15 & 22), 434 S. State. Free. (734) 764–9304.

Aug. 8, 11, 18, & 29 (different times). A chance for adults to learn the basics of printing with movable type. Noon–2 p.m. (Aug. 8), 5–7 p.m. (Aug. 11 & 18), and 1–3 p.m. (Aug. 29), AADL Downtown, Secret Lab. Free. (734) 327–4200.