Peary (crater)
Encyclopedia
Peary is the closest large lunar
impact crater
to the lunar north pole. At this latitude the crater interior receives little sunlight, and parts of the southern floor remain permanently cloaked in shadow. From the Earth
the crater appears on the northern lunar limb, and is seen from the side.
The crater is nearly circular, with an outward bulge along the northeast rim. There is a gap in the southwestern rim, where it joins a slightly smaller worn crater formation. The outer rim of Peary is worn and eroded, creating a rugged mountainous ring that produces long shadows across the crater floor.
The crater floor is relatively flat, but marked by several small craterlets, particularly in the eastern half. The southern third of the interior remains cloaked in shadows, and so its features cannot be readily discerned.
The worn and lava
-flooded crater Byrd
lies close to the southern rim of Peary. To the northwest, about a quarter the way around the lunar pole, is the larger crater Hermite
. On the opposite side of the pole, on the far side of the Moon, lies the still-larger Rozhdestvenskiy
.
In 2004, a team led by Dr. Ben Bussey
of Johns Hopkins University
using images taken by the Clementine mission
determined that four mountainous regions on the rim of Peary appeared to remain illuminated for the entire lunar day. These unnamed "mountains of eternal light
" are possible due to the Moon's extremely small axial tilt, which also gives rise to permanent shadow at the bottoms of many polar craters. No similar regions of eternal light exist at the less-mountainous south pole
. Clementine's images were taken during the northern lunar hemisphere's summer season, and it remains unknown whether these four mountains are shaded at any point during their local winter season.
The northern rim of Peary is considered a likely site for a future Moon base due to this steady illumination, which would provide both a relatively stable temperature and an uninterrupted solar power supply. It is also near permanently shadowed areas that may contain some quantity of frozen water
.
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...
to the lunar north pole. At this latitude the crater interior receives little sunlight, and parts of the southern floor remain permanently cloaked in shadow. From the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
the crater appears on the northern lunar limb, and is seen from the side.
The crater is nearly circular, with an outward bulge along the northeast rim. There is a gap in the southwestern rim, where it joins a slightly smaller worn crater formation. The outer rim of Peary is worn and eroded, creating a rugged mountainous ring that produces long shadows across the crater floor.
The crater floor is relatively flat, but marked by several small craterlets, particularly in the eastern half. The southern third of the interior remains cloaked in shadows, and so its features cannot be readily discerned.
The worn and 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...
-flooded crater Byrd
Byrd (lunar crater)
Byrd is an irregular lunar crater that is located near the north pole of the Moon. The north rim of Byrd is nearly connected to the crater Peary, a formation that is adjacent to the pole. The smaller crater Gioja is attached to the remains of the southwest rim....
lies close to the southern rim of Peary. To the northwest, about a quarter the way around the lunar pole, is the larger crater Hermite
Hermite (crater)
Hermite is a lunar impact crater located along the northern lunar limb, close to the north pole of the Moon. It was first discovered in 1964. To the west is the crater Rozhdestvenskiy, and to the south are Lovelace and Sylvester. Grignard is located directly adjacent to the Southwest...
. On the opposite side of the pole, on the far side of the Moon, lies the still-larger Rozhdestvenskiy
Rozhdestvenskiy (crater)
Rozhdestvenskiy is a large lunar crater that is located on the far side of the Moon, within one crater diameter of the north pole. It lies sandwiched between the craters Hermite along the eastern rim, and Plaskett which intrudes slightly into the west-southwestern rim...
.
In 2004, a team led by Dr. Ben Bussey
Ben Bussey
Ben J. Bussey is a planetary scientist.He earned a Ph.D. in planetary geology at University College London, England. In 2001, during his post-doctorate work at the University of Hawaii, he joined the ANSMET expedition to recover meteorites from the Antarctic glaciers...
of Johns Hopkins University
Johns Hopkins University
The Johns Hopkins University, commonly referred to as Johns Hopkins, JHU, or simply Hopkins, is a private research university based in Baltimore, Maryland, United States...
using images taken by the Clementine mission
Clementine mission
Clementine was a joint space project between the Ballistic Missile Defense Organization and NASA...
determined that four mountainous regions on the rim of Peary appeared to remain illuminated for the entire lunar day. These unnamed "mountains of eternal light
Peak of Eternal Light
Peak of Eternal Light describes a point on a body within the Solar System which is eternally bathed in sunlight. This is due to both the bodies' rotation and the point's altitude...
" are possible due to the Moon's extremely small axial tilt, which also gives rise to permanent shadow at the bottoms of many polar craters. No similar regions of eternal light exist at the less-mountainous south pole
Lunar south pole
The lunar south pole is of special interest to scientists because of the postulated occurrence of ice in permanently shadowed areas. Of the lunar poles, the south pole is of greater interest because the area that remains in shadow is much larger than that at the north pole. The lunar south pole...
. Clementine's images were taken during the northern lunar hemisphere's summer season, and it remains unknown whether these four mountains are shaded at any point during their local winter season.
The northern rim of Peary is considered a likely site for a future Moon base due to this steady illumination, which would provide both a relatively stable temperature and an uninterrupted solar power supply. It is also near permanently shadowed areas that may contain some quantity of frozen water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
.
External links
- Researchers find ideal spot for moon base, CNN, April 18, 2005 (accessed 2010 August 22)