This weekend the Toledo Astronomical Association in cooperation with the Astronomical League of the United States will host a variety of activities to mark the 2015 Astronomy Day, a grassroots movement designed to share the joy of astronomy with the general population.

Astronomy Day Toledo includes: viewing at Olander’s Sylvan Prairie, 9 p.m. to midnight Friday. Objects of interest include the Orion Nebula, the Beehive Cluster, Jupiter, Saturn, and a first quarter moon. On Saturday, noon to 4 p.m., solar viewing at Fallen Timbers Mall, and 12:30 to 4:30 p.m., solar viewing, University of Toledo, Outside Ritter Planetarium. The sun has been moderately active recently and it is likely that there will be one or more sun spots for viewing.

The University of Toledo Ritter Planetarium will feature at 1 p.m. The Case of the Disappearing Planet. Skye Watcher discovers what happened to the ex-planet Pluto as she tracks down clues that stretch back hundreds of years. The program looks into the changing status of planets in our Solar System. At 2 p.m., Black Holes, The Other Side of Infinity, narrated by actor Liam Neeson, features high-resolution visualizations of cosmic phenomena.

At 3 p.m., UT and the Discovery Channel Telescope will present a 45-minute film, Scanning the Skies produced by the Discovery Channel. This documentary looks at the history of the Lowell Observatory in Flagstaff, Ariz., and the decision to build a new observatory. Details will be presented about the role UT has in using this telescope.

There will be continuous tours of the Ritter One-Meter Telescope from 1 to 4 p.m. See Venus through our telescope during the day.

All programs are free. For details, contact Frank S. Merritt, frank.merritt@utoledo.edu or 419-535-8775 .

First Published April 23, 2015, 4:00 a.m.