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Giordano Bruno (crater)
Encyclopedia
Giordano Bruno is a 22 km lunar
impact crater
on the far side of the Moon
, just beyond the northeastern limb. At this location it lies in an area that can be viewed during a favorable libration
, although at such times the area is viewed from the side and not much detail can be seen. It lies between the craters Harkhebi
to the northwest and Szilard
to the southeast.
When viewed from orbit
, Giordano Bruno is at the center of a symmetrical ray system
of ejecta that has a higher albedo
than the surrounding surface. The ray material extends for over 150 kilometers and has not been significantly darkened by space erosion. Some of the ejecta appears to extend as far as the crater Boss
, over 300 km to the northwest. The outer rim of the crater is especially bright, compared to its surroundings. To all appearances this is a young formation that was created in the relatively recent past, geologically speaking. The actual age is unknown, but is estimated to be less than 350 million years.
This feature was named after the Italian philosopher Giordano Bruno
.
s from Canterbury
reported to the abbey's chronicler, Gervase
, that shortly after sunset on June 18, 1178, they saw "two horns of light" on the shaded part of the Moon. In 1976 the geologist Jack B. Hartung proposed that this described the formation of the crater Giordano Bruno.
Modern theories predict that there would be a plume of molten matter rising up from the surface of the Moon, which is consistent with the monks' description. In addition, the location they recorded fits in well with the crater's location. Additional evidence of Giordano Bruno's youth is its spectacular ray system
: because micrometeorites constantly rain down, they kick up enough dust to quickly (in geological terms) erode a ray system. So there is probably enough circumstantial evidence to hold that Giordano Bruno was formed during human history.
More circumstantial evidence that Giordano Bruno was formed by an impact is the fact that the monks' observation took place during the Beta Taurid
meteor shower. This meteor shower, which happens in late June, was possibly responsible for the Tunguska event
.
However, the question of the crater's age is not that simple. The impact creating the 22-km-wide crater would have kicked up enough debris to trigger a week-long, blizzard-like meteor storm on Earth – yet no accounts of such a noteworthy storm of unprecedented intensity are found in any known historical records, including the European, Chinese, Arabic, Japanese and Korean astronomical archives.http://science.nasa.gov/headlines/y2001/ast26apr_1.htm This discrepancy is a major objection to the theory that Giordano Bruno was formed at that time.
All this raises the question of what the monks saw. An alternative theory holds that the monks just happened to be in the right place at the right time to see an exploding meteor coming at them and aligned with the Moon. Because meteors appear about 45 to 75 miles up in the atmosphere, http://www.nasa.gov/worldbook/meteor_worldbook.html the laws of geometric perspective
dictate that only a relatively small area in Britain
would have the perfect geometry to make it look like it was on 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 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...
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...
, just beyond the northeastern limb. At this location it lies in an area that can be viewed during a favorable libration
Libration
In astronomy, libration is an oscillating motion of orbiting bodies relative to each other, notably including the motion of the Moon relative to Earth, or of Trojan asteroids relative to planets.-Lunar libration:...
, although at such times the area is viewed from the side and not much detail can be seen. It lies between the craters Harkhebi
Harkhebi (crater)
Harkhebi is a large lunar crater of the category termed a walled plain. Half of the crater to the north-northwest is overlain by the walled plain Fabry, a large formation in its own right. Attached to the northwestern rim is the much smaller crater Vashakidze...
to the northwest and Szilard
Szilard (crater)
Szilard is a damaged lunar crater that lies to the east-northeast of the crater Richardson. It is named after Leo Szilard, the scientist who theorised nuclear chain reactions and famously worked on the atomic bomb during WWII. About a half-crater-diameter to the northwest is the large walled plain...
to the southeast.
When viewed from orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
, Giordano Bruno is at the center of a symmetrical ray system
Ray system
A ray system comprises radial streaks of fine ejecta thrown out during the formation of an impact crater, looking a bit like many thin spokes coming from the hub of a wheel. The rays can extend for lengths up to several times the diameter of their originating crater, and are often accompanied by...
of ejecta that has a higher 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 surface. The ray material extends for over 150 kilometers and has not been significantly darkened by space erosion. Some of the ejecta appears to extend as far as the crater Boss
Boss (crater)
Boss is a lunar impact crater that is located along the northeast rim of the Moon's near side. Due to its location, the crater is viewed from the side by observers on the Earth, and its visibility is subject to libration effects....
, over 300 km to the northwest. The outer rim of the crater is especially bright, compared to its surroundings. To all appearances this is a young formation that was created in the relatively recent past, geologically speaking. The actual age is unknown, but is estimated to be less than 350 million years.
This feature was named after the Italian philosopher Giordano Bruno
Giordano Bruno
Giordano Bruno , born Filippo Bruno, was an Italian Dominican friar, philosopher, mathematician and astronomer. His cosmological theories went beyond the Copernican model in proposing that the Sun was essentially a star, and moreover, that the universe contained an infinite number of inhabited...
.
Formation
Five monkMonk
A monk is a person who practices religious asceticism, living either alone or with any number of monks, while always maintaining some degree of physical separation from those not sharing the same purpose...
s from Canterbury
Canterbury
Canterbury is a historic English cathedral city, which lies at the heart of the City of Canterbury, a district of Kent in South East England. It lies on the River Stour....
reported to the abbey's chronicler, Gervase
Gervase of Canterbury
Gervase of Canterbury was an English chronicler.- Life :...
, that shortly after sunset on June 18, 1178, they saw "two horns of light" on the shaded part of the Moon. In 1976 the geologist Jack B. Hartung proposed that this described the formation of the crater Giordano Bruno.
Modern theories predict that there would be a plume of molten matter rising up from the surface of the Moon, which is consistent with the monks' description. In addition, the location they recorded fits in well with the crater's location. Additional evidence of Giordano Bruno's youth is its spectacular ray system
Ray system
A ray system comprises radial streaks of fine ejecta thrown out during the formation of an impact crater, looking a bit like many thin spokes coming from the hub of a wheel. The rays can extend for lengths up to several times the diameter of their originating crater, and are often accompanied by...
: because micrometeorites constantly rain down, they kick up enough dust to quickly (in geological terms) erode a ray system. So there is probably enough circumstantial evidence to hold that Giordano Bruno was formed during human history.
More circumstantial evidence that Giordano Bruno was formed by an impact is the fact that the monks' observation took place during the Beta Taurid
Beta Taurids
The Beta Taurids are an annual meteor shower belonging to a class of "daytime showers" that peak after sunrise.The Beta Taurids are normally active from June 5 to July 18. They emanate from an average...
meteor shower. This meteor shower, which happens in late June, was possibly responsible for the Tunguska event
Tunguska event
The Tunguska event, or Tunguska blast or Tunguska explosion, was an enormously powerful explosion that occurred near the Podkamennaya Tunguska River in what is now Krasnoyarsk Krai, Russia, at about 7:14 a.m...
.
However, the question of the crater's age is not that simple. The impact creating the 22-km-wide crater would have kicked up enough debris to trigger a week-long, blizzard-like meteor storm on Earth – yet no accounts of such a noteworthy storm of unprecedented intensity are found in any known historical records, including the European, Chinese, Arabic, Japanese and Korean astronomical archives.http://science.nasa.gov/headlines/y2001/ast26apr_1.htm This discrepancy is a major objection to the theory that Giordano Bruno was formed at that time.
All this raises the question of what the monks saw. An alternative theory holds that the monks just happened to be in the right place at the right time to see an exploding meteor coming at them and aligned with the Moon. Because meteors appear about 45 to 75 miles up in the atmosphere, http://www.nasa.gov/worldbook/meteor_worldbook.html the laws of geometric perspective
Perspective (visual)
Perspective, in context of vision and visual perception, is the way in which objects appear to the eye based on their spatial attributes; or their dimensions and the position of the eye relative to the objects...
dictate that only a relatively small area in Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
would have the perfect geometry to make it look like it was on the Moon.