What was Lost is Found

The crew of the Valkyrie continue their explorations as they also look for any sign of the defiled. What they do find is a crashed Romulan D7 and the remains of an old Constellation Class ship, the USS Ulysses, that had been reported missing near the Romulan Neutral Zone on SD 7396 (2271).

How did vessels from over 100 years in the past get light years from where they were supposed to be?