Here is an extract from an article by Christopher Pittman from 2000, which is based on a book by John Winthrop, 'The History of New England, 1630-1639'.
"One night in March of 1639*, James Everell ("a sober, discreet man"- Winthrop) and two companions boarded a little boat and set out for a trip on the Muddy River in Boston. They had been moving downstream for about a mile when the night's mysterious events began. The three men were suddenly confronted with the appearance of a huge, bright light hovering in the sky. The light "flamed up" as it hovered and appeared to be about "three yards square." As they watched, the light "contracted into the figure of a swine" and moved "swift as an arrow" in the direction of Charlton. For two or three hours, the unidentified light moved back and forth in the sky between Everell's location and Charlton. When the light finally disappeared, the men noticed to their dismay that they had somehow been carried against the tide back to the place where they had started their trip! Governor Winthrop noted, "Divers[e] other credible persons saw the same light, after, about the same place." Some witnesses said the light was occasionally seen shooting out flames and sparks, and indeed, two UFOs matching that description were again seen in Boston in 1644."