The National Museum of Mathematics offers sessions specifically aimed at senior citizens. Program directors in senior citizen centers may be interested in this.
The National Museum of Mathematics offers online sessions, some recurring regularly, for people of all ages, including some designed for senior citizens.
The ECHO Leahy Center for lake Champlain in Burlington Vermont offers a page that links to a wide assortment of activities and videos, including citizen science opportunities.
MOS at Home comes from the Boston Museum of Science. They offer videos, podcasts, and activities as well as virtual exhibits.
Science at Home from the Connecticut Science Center features virtual programs and videos as well as science activities for all ages.
Brookhaven National Laboratory provides a webpage of general activities as well as "Discover Brookhaven" challenges that award a certificate upon completion.
The Boonshoft Museum of Discovery in Dayton, Ohio offers a page of DIY Science Activities with easy to get materials, step by step instructions, and a basic science explanation for families to download and use. There is also some virtual programming on this site.
The Asheville Museum of Science in North Carolina provides a daily newsletter with learning activities. More resources are also located on their YouTube channel.