Antoniadi (lunar crater)
Encyclopedia
Antoniadi is a large lunar
impact crater
that lies on the southern hemisphere
on the far side of the Moon
. The crater intrudes into the southeastern rim of the crater Minnaert
, a slightly smaller formation that is significantly more eroded. Attached to the eastern rim of Antoniadi is Numerov
, another large, ancient crater similar to Minnaert. Due south of Antoniadi is the small crater Brashear
.
The outer rim of Antoniadi is generally circular, with an irregular edge that has multiple indentations all about the perimeter. The wall is only lightly eroded, and retains a crisp rim and terracing on the inner walls. Only a single small craterlet of note lies across the interior wall, near the southeast edge of the rim.
Antoniadi is one of the few craters on the Moon that possesses both a second inner ring and a central peak. This inner ring formation is about half the diameter of the outer wall, and only rugged mountain segments of the ring to the north and south still remain. The western part of the inner ring is almost non-existent, and only a few minor hills remain to the east.
The floor within the inner wall is unusually flat and smooth, with the central peak being the only notable feature. The floor outside the inner ring is much rougher in texture. The most notable crater on the interior floor lies across the eastern edge of the southern inner ring range.
The bottom of Antoniadi crater is measured - by using the laser altimeter (LALT) instrument on board the Japanese Selenological and Engineering Explorer (SELENE
) satellite - to be the lowest point on the moon and rests 9 kilometers (more than 5.5 miles) deep.
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 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 lies on 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...
. The crater intrudes into the southeastern rim of the crater Minnaert
Minnaert (crater)
Minnaert is a large lunar crater that is located on the far side of the Moon, deep in the southern hemisphere. It is partly overlain along the southeastern side by the larger and younger crater Antoniadi. To the west-northwest lies Lyman....
, a slightly smaller formation that is significantly more eroded. Attached to the eastern rim of Antoniadi is Numerov
Numerov (crater)
Numerov is a lunar impact crater that is located on the Moon's far side, deep in the southern hemisphere. It is attached to the larger and younger crater Antoniadi to the west, and the outer rampart of Antoniadi overlies the inner wall and part of the western interior floor of Numerov...
, another large, ancient crater similar to Minnaert. Due south of Antoniadi is the small crater Brashear
Brashear (lunar crater)
Brashear is a lunar crater on the far side of the Moon, in the southern hemisphere in the vicinity of the south pole. It lies just to the south of the walled plain Antoniadi, within the larger crater's outer rampart of ejecta...
.
The outer rim of Antoniadi is generally circular, with an irregular edge that has multiple indentations all about the perimeter. The wall is only lightly eroded, and retains a crisp rim and terracing on the inner walls. Only a single small craterlet of note lies across the interior wall, near the southeast edge of the rim.
Antoniadi is one of the few craters on the Moon that possesses both a second inner ring and a central peak. This inner ring formation is about half the diameter of the outer wall, and only rugged mountain segments of the ring to the north and south still remain. The western part of the inner ring is almost non-existent, and only a few minor hills remain to the east.
The floor within the inner wall is unusually flat and smooth, with the central peak being the only notable feature. The floor outside the inner ring is much rougher in texture. The most notable crater on the interior floor lies across the eastern edge of the southern inner ring range.
The bottom of Antoniadi crater is measured - by using the laser altimeter (LALT) instrument on board the Japanese Selenological and Engineering Explorer (SELENE
SELENE
SELENE , better known in Japan by its nickname after the legendary Japanese moon princess, was the second Japanese lunar orbiter spacecraft. Produced by the Institute of Space and Astronautical Science and the National Space Development Agency , both now part of the Japan Aerospace Exploration...
) satellite - to be the lowest point on the moon and rests 9 kilometers (more than 5.5 miles) deep.