The town is inviting residents to take part in a local observance of National Night Out this Tuesday from 4:30 to 8 p.m. at the senior center, 175 Chandler St. National Night Out is an annual anticrime and antidrug campaign sponsored by the National Association of Town Watch that features organized activities on a designated night in communities across the United States and Canada. The Tewksbury event, a free Family Night, is being organized by the Police Department in partnership with the senior center and the library, with support from local businesses. It will include a classic car show and visits from Snoopy and the Lowell Spinners’ Canaligator. The Police Department will provide children’s identification kits. Also available will be temporary tattoos, giveaways, and the showing of the Disney movie “Cars” on a big screen starting at 6 p.m. For more information, contact police Officer Jennie Welch at 978-851-7373, ext. 230. Meanwhile, the Tewksbury Historical Society on Sunday is holding its fourth annual group hike to search for a plant, Scots heather, that played a role in Tewksbury history. The hike begins at 1 p.m. at the Community Gardens parking lot on Livingston Street.