Boris is a tiny lunar

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 crater

Impact crater

In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

 that is located on the Mare Imbrium

Mare Imbrium

Mare Imbrium, Latin for "Sea of Showers" or "Sea of Rains", is a vast lunar mare filling a basin on Earth's Moon and one of the larger craters in the Solar System. Mare Imbrium was created when lava flooded the giant crater formed when a very large object hit the Moon long ago...

, to the northeast of the crater Delisle

Delisle (crater)

Delisle is a small lunar crater in the western part of the Mare Imbrium. It lies to the north of the crater Diophantus, and just to the northwest of the ridge designated Mons Delisle. Between Delisle and Diophantus is a sinuous rille named Rima Diophantus, with a diameter of 150 km...

. It lies at the southwest extremity of a sinuous rille

Rille

Rille is typically used to describe any of the long, narrow depressions in the lunar surface that resemble channels. Typically a rille can be up to several kilometers wide and hundreds of kilometers in length...

 that is designated Rima Delisle. This rille meanders to the northeast, towards the crater Heis

Heis (crater)

Heis is a small lunar impact crater that is located in the western part of the Mare Imbrium. It is located to the northeast of the crater Delisle, and south of C. Herschel. This is a circular, symmetrical formation with an interior floor that is about half the diameter of the outer rim...

, before vanishing into the lunar mare

Lunar mare

The lunar maria are large, dark, basaltic plains on Earth's Moon, formed by ancient volcanic eruptions. They were dubbed maria, Latin for "seas", by early astronomers who mistook them for actual seas. They are less reflective than the "highlands" as a result of their iron-rich compositions, and...

.

This is one of the smallest craters on the Moon to be officially given a name by the IAU

International Astronomical Union

The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...

.