An item in the Weekend section Friday incorrectly listed the date for the National Aeronautics and Space Administration's 40th-anniversary celebration at the Goddard Space Flight Center on Wallops Island, Va. The open house and tours were held yesterday, and the facilities will not be open to the public today.

Direct from New York, the exhibit "A Picture of Medieval Life" opens this week in a rather unusual space -- the atrium of Children's Hospital. On loan from the Metropolitan Museum of Art, the show features objects and prints detailing everyday medieval life, from kitchen utensils to pieces of armor and personal adornments. In conjunction with the exhibit, the Washington Calligraphers Guild has organized a show of calligraphic art, from medieval to modern.

Admission to the following activities is free unless otherwise noted.

A PICTURE OF MEDIEVAL LIFE -- Friday, Saturday and Sunday, 9 to 8. The Atrium, Children's Hospital, 111 Michigan Ave. NW. Presents everyday objects of medieval life along with calligraphic works. 745-3325 or 942-3357.

WANDER WHERE YOUR WINE GROWS -- Friday and Saturday, 10 to 6, Sunday, 12 to 6, Berry Wine Plantations and Linganore Winecellars, 13601 Glisans Mill Road, Mt. Airy, Md. Tour/taste, $2. 301/662-8687.

OLD MARYLAND'S FARM -- Friday-Sunday, 11 to 4, Watkins Regional Park, 301 Watkins Park Dr., Upper Marlboro. The farm has a variety of animals, a greenhouse, blacksmith shop, colonial herb garden and organic garden plots. 249-6202.

NATIONAL GLASS COLLECTORS' SHOW -- Saturday, 11 to 9, Sunday, 11 to 6. Sheraton Hotel and Exhibition Center, I-95 Beltway Exit 20B, New Carrollton. Features antique and contemporary dealers, studio artists, glass repair and spun glass demonstration. Books and glassware for sale. Admission includes two lectures with slides. $3.50. 441- 1300 or 459-6700 ext. 1913.

FLEA MARKET -- Saturday, 10 to 2, Seat Pleasant Activities Center, 5720 Addison Rd., Seat Pleasant. 773-6685.

FLEA MARKET -- Saturday, 10 to 3, Providence Recreation Center, 7525 Marc Dr., Falls Church. 698-1351.

WALKING TOUR OF ALEXANDRIA -- Saturday, 10:30 a.m., Ramsay House Visitors' Center, 221 King St. Last Saturday for a 60- to 80-minute tour of the historic district by a guide in colonial dress. $3. $1.50 for students seven to 17 years. 549-0205 or 548-0100.

USA FOR AFRICA CAR WASH -- Saturday, noon to 3, Mr. Wash, 6815 Annapolis Rd., Landover, by WKYS-FM radio and Penguin Feather Records. Proceeds from car wash, T-shirt, poster and album sales go to the "USA for Africa" campaign. 322-3370.

FREEDANSE DEMONSTRATIONS -- Saturday, noon to 8, Tysons Corner Center. Dance music with a difference and an aerobics workout that teaches you to dance. 556-6556.

ANTIQUE AND CLASSIC CAR SHOW -- Sunday, 9 to 4, Morven Park, Old Waterford Road, Leesburg. Leesburg Host Lion's Club program includes a flea mearket, house-and- garden tours and a tour of the Carriage Museum. $3 for adults, children under seven free, $2 for senior citizens. 703/777-7837.

NASA OPEN HOUSE -- Sunday, 10 to 5, Goddard Space Flight Center, Wallops Flight Facility, Wallops Island, Va. 40th anniversary celebration with tours and walkthroughs. Air Force F-15 demonstration at 2; movies, refreshments. 804/824-3411, ext. 579.

LAWN BOWLING -- Sunday, 1 to 4, Sully Plantation, Sully Road off U.S. 50, Chantilly. Test your skill in a favorite game of 18th- century Virginia. $2 for adults, $1 for children. 437-1794.

VICTORIANS AT PLAY -- Sunday, 1 to 5, Clara Barton National Historic Site, 5801 Oxford Rd., Glen Echo. Take a look at a 19th- century stereoscope and views of leisure activities of 1863-1910. 492-6245.

EVERYDAY ECOLOGY -- Sunday at 2, Potomac Overlook Regional Park Nature Center, Marcy Road off Military Road. Find out how ecology affects daily life. 528-5406.

ICE CREAM SOCIAL -- Sunday, 2 to 5, Hyatt Regency Crystal City, 2799 Jefferson Davis Highway, Arlington. To benefit the Arlington Symphony, musical ensembles will play while ice cream and cookies are served in the ballroom. $2. 558-3066.

SINGLES' MOVIE NIGHT -- Sunday, 7:30 p.m., Jewish Community Center of Greater Washington, 6125 Montrose Rd., Rockville. Popcorn and a movie on wide-screen TV; then make your own sundae. $4.50 for non-members. 949-7062.