Poisson is a lunar crater that is located in the southern highlands 's near side. It lies to the east of the crater Aliacensis and northwest of Gemma Frisius. To the northwest is Apianus. This heavily eroded crater shares a common floor with the satellite crater Poisson T to the west-southwest, and the two craters have more or less merged into a single formation with a narrower neck in between. (wikipedia entry)
