Poincaré (crater)
Encyclopedia
Poincaré is a large lunar
impact basin
that lies in the southern hemisphere
on the far side of the Moon
. Most of the formation has been heavily eroded by subsequent impacts, leaving a battered formation with only rugged remnants of the original outer rim to the west.
The eastern half has been completely worn away, and much of the interior has been resurfaced by lava
flows. This surface has a lower albedo
than the surrounding terrain, giving it a dark appearance. A rugged formation forms a low north-south range across the eastern section of the floor, possibly the remnant of an inner ring.
The perimeter of Poincaré has several notable craters. To the north is the crater Hopmann
, while the craters Abbe
and Hess
lie to the east. Directly to the west is Planck
, a walled plain of similar dimensions to Poincaré. Both formations are sufficiently large to have formed a small lunar mare
on the near side face of the Moon.
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...
impact basin
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 lies in the southern hemisphere
Sphere
A sphere is a perfectly round geometrical object in three-dimensional space, such as the shape of a round ball. Like a circle in two dimensions, a perfect sphere is completely symmetrical around its center, with all points on the surface lying the same distance r from the center point...
on the far side of the Moon
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...
. Most of the formation has been heavily eroded by subsequent impacts, leaving a battered formation with only rugged remnants of the original outer rim to the west.
The eastern half has been completely worn away, and much of the interior has been resurfaced by lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...
flows. This surface has a lower albedo
Albedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...
than the surrounding terrain, giving it a dark appearance. A rugged formation forms a low north-south range across the eastern section of the floor, possibly the remnant of an inner ring.
The perimeter of Poincaré has several notable craters. To the north is the crater Hopmann
Hopmann (crater)
Hopmann is a lunar crater that lies in the southern hemisphere on the Moon's far side. It is attached to the northern part of the large walled plain Poincaré. Less than one crater diameter to the north-northwest is the crater Garavito....
, while the craters Abbe
Abbe (crater)
Abbe is a lunar impact crater that is located in the southern hemisphere on the far side of the Moon. It is located just to the south of the crater Hess, and lies to the east of the large walled basin Poincaré. It is named after the German physicist Ernst Abbe.The outer wall of Abbe is somewhat...
and Hess
Hess (crater)
Hess is a lunar crater that lies in the southern hemisphere on the far side of the Moon. The crater rim has been worn by subsequent impacts, leaving a low, eroded outer wall. The flat interior has been resurfaced by lava flows and is free of significant impacts...
lie to the east. Directly to the west is Planck
Planck (crater)
Planck is a huge lunar crater that is located in the southern hemisphere of the Moon, on the far side as seen from the Earth. It lies to the west of the walled plain Poincaré, another enormous formation only slightly larger than Planck. Both formations are larger than the walled plain Bailly, the...
, a walled plain of similar dimensions to Poincaré. Both formations are sufficiently large to have formed a small 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...
on the near side face of the Moon.
Satellite craters
By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Poincaré.| Poincaré | Latitude | Longitude | Diameter |
|---|---|---|---|
| C | 54.4° S | 169.0° E | 20 km |
| J | 59.4° S | 168.7° E | 20 km |
| Q | 59.3° S | 160.9° E | 26 km |
| R | 60.2° S | 155.0° E | 52 km |
| X | 53.8° S | 161.9° E | 19 km |
| Z | 53.7° S | 164.9° E | 35 km |