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].

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].

Aug. 8 & 29 (different times). All invited to drop in and tour the historic building, view exhibits, participate in astronomy-related activities, and use the observatory’s telescopes (weather permitting). On Aug. 29, the observatory is open late to observe the night sky with the 1857 Fitz telescope. Noon–5 p.m. (Aug. 8) & noon–11 p.m. (Aug. 29), 1398 E. Ann at Observatory. Free. (734) 763–2230, detroitobservatory.umich.edu.

Every Sat. & Sun. Hands-on 20-minute family-oriented demo for kids age 5 & up that uses museum specimens to explore paleontology and what can be learned from giant bones and fossils. 12:30 & 2:30 p.m., 1105 North University. Free. (734) 764–0478, ummnh.org. 

This 15-year-old club plays baseball using 1860s-era rules against similar teams from around the region. Today, they play Kalamazoo’s 13-year-old club, a revival of a club first founded in 1860. 1 p.m., Timbertown Park, Sibley (west off Main north of downtown), Chelsea. Free. (248) 930–6130, [email protected], chelseamonitors.com.

Game vs. vs. Wyandotte Stars Base Ball Club. This 14-year-old club plays baseball using 1860s-era rules against similar teams from around the region, today against Wyandotte’s 19-year-old team. The month’s remaining home games include one against the Monitor Base Ball Club of Chelsea (Aug. 8), and the Wahoo Base Ball Club of Royal Oak (Aug. 29). 1 p.m., Webster Township Hall, 5665 Webster Church Rd., Dexter. Free. [email protected], unionbbc.com.

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.

Every Sat. Thirty–minute tour of the museum’s exhibits and galleries, as well as an introduction to some current U-M Biological Sciences research projects. 1:30 p.m., 1105 North University. Free. Limited capacity. Sign up at the welcome desk. (734) 764–0478.