THE USS Missouri, the battleship where Japan formally surrendered to end World War II, has been opened for viewing this summer and fall in Bremerton, Wash. While the war's bomber planes - some of which have been touring the United States this year - seem small relative to even the smallest of today's passenger jetliners, visitors to the ''Mighty Mo'' are struck by the massive scale of the ship and its armaments. Almost three football fields long (887 feet), the ship had a complement of 2,500 Navy personnel when it was launched in January 1944. Its main-battery guns could fire 16-inch-diameter shells the weight of Volkswagen Beetles accurately at targets 23 miles away - and do this at a rate of 18 shells a minute. What most impresses 12-year-old visitor Aaron Baumgartner, however, is the plaque on the ''surrender deck'' commemorating Sept. 2, 1945. On that day, Gen. Douglas MacArthur and Adm. Chester Nimitz accepted Japan's surrender as the ship lay at anchor. (A renegade Japanese plan to bomb the battleship as it entered Tokyo Bay was narrowly averted.) A recording of MacArthur's speech on that day fills the air, expressing his hope that ''a better world shall emerge out of the blood and carnage of the past - a world dedicated to the dignity of man and the fulfillment of his most cherished wish for freedom, tolerance, and justice.'' Aaron, visiting with 22 family members and friends from Genesee, Idaho, says he also enjoyed the nearby wardroom. That area, where the ship's 134 officers dined, has been turned into an exhibit hall. Among the attractions: a diagram of the ship (most of which is still closed to the public), historic photos and documents, a map of the ship's service history, and a video presentation about its role in the recent Gulf war. The cabins of the captain and executive officer are also open to viewers. The ship, one of four Iowa-class battleships, was the last one built by the US. (The other three were the Iowa, New Jersey, and Wisconsin.) The Missouri was decommissioned after the Korean War, then recommissioned in 1986 with a 1,500-member crew and modern missile systems replacing several guns. Today, taking the ship on tour would be prohibitively expensive for the Navy. But for anyone passing through Seattle, the Missouri is only an hour's ferry ride away - plus a short drive to the Naval Inactive Ships Maintenance Facility. The 50th anniversary of the Japanese surrender will be marked with a special ceremony Sept 2. After this fall, the ship's future is uncertain. Some organizations want it as a museum, according to Navy spokesman John Gorton. The Navy is evaluating several offers. SEPT. 2, 1945: (Above) The Japanese military and diplomatic delegation, headed by Foreign Minister Mamoru Shigemitsu (with cane) and Gen. Yoshijiro Umezu (front, right), arrive aboard the USS Missouri in Tokyo Bay to sign the formal surrender ending World War II. Today, a plaque commemorating the event (left) is set into the weathered teak decking of the battleship, which is now inactive but open to visitors this summer and fall.