Winthrop (Moon)

Named after John Winthrop - American astronomer (1714-1779).

Winthrop is the remnant of a lunar crater that has been flooded by lava from the Oceanus Procellarum. It lies across the western rim of the much larger crater Letronne, a much larger feature that has been nearly destroyed by the intruding mare lavas. All that survives are a few segments of the outer rim. (wikipedia entry)

A crater is a circular depression likely created by an impact event. On the Moon they are named after deceased scientists, polar explorers, astronauts or cosmonauts.