As part of Smithsonian Magazine’s annual museum day on Saturday, Sept. 27, the Martha’s Vineyard Museum in Edgartown will open its doors free of charge from 10 am to 5 pm. This is the third straight year the M.V. Museum has participated in the event, in which more than 1,300 museums across the country offer free admission in a celebration of culture and learning. Current exhibits include “Moore and Moore and Moore,” about three generation of Vineyard artists, and “Sea Change: Martha’s Vineyard in the 1960s.” Tickets can be printed at smithsonian.com/museumday. For more information, visit mvmuseum.org.