| |
SMART-1: the Moon from ESA
|
|
|
31-Gassendi.jpgGassendi Crater62 visiteCaption ESA originale:"This mosaic of 2 images, taken by the advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows the inside of crater Gassendi. AMIE obtained these images on 13 January 2006, 1' apart from each other, from a distance of about 1220 Km(top frame) and 1196 Km (bottom frame) from the surface, with a ground resolution of 110 and 108 mt per pixel, respectively.
The area shown in the top image is centred at a Latitude of 16,2º South and Longitude 40,2º West, while the bottom images is centred at a Latitude of 17,9º South and Longitude 40,2º West.
Gassendi is an impact feature located on the Near Side of the Moon, at the Northern Edge of Mare Humorum. The crater is actually much larger than the field of view visible in this image. The hills on the lower right of the mosaic are the central peak of the crater, with a height of roughly 1,2 Km. The crater almost fully visible on the top is called Gassendi A".
|
|
32-MareHumorum.jpgMare Humorum61 visiteThis mosaic of three images, taken by the advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows Mare Humorum on the Moon.
AMIE obtained the top frame on 1 January 2006, from a distance of 1087 kilometres from the surface, with a ground resolution of 98 metres per pixel. The remaining two frames were taken on 13 January 2006, from a distance of about 1069 (centre) and 1050 kilometres (bottom) from the surface, with a ground resolution of 97 and 95 metres per pixel, respectively.
The area shown in the top image is centred at a latitude of 40.2º South and longitude 25.9º West; the centre image is centred at a latitude of 40.2º South and longitude 27.3º West; the bottom image is centred at a latitude of 40.2º South and longitude 28.8º West.
Mare Humorum, or 'Sea of Moisture', is a small circular mare on the lunar nearside, about 825 kilometres across. The mountains surrounding it mark the edge of an old impact basin which has been flooded and filled by mare lavas. These lavas also extend past the basin rim in several places. In the upper right are several such flows which extend northwest into southern Oceanus Procellarum.
Mare Humorum was not sampled by the Apollo program, so its precise age could not been determined yet. However, geologic mapping indicates that its age is in between that of the Imbrium and the Nectaris basins, suggesting an age of about 3.9 thousand million years (with an uncertainty of 500 million years).
Humorum is filled with a thick layer of mare basalt, believed to exceed 3 kilometres in thickness at the centre of the basin. On the north edge of Mare Humorum is the large crater Gassendi, which was considered as a possible landing site for Apollo 17.
Mare Humorum is a scientifically interesting area because it allows the study of the relationships among lunar mare filling, mare basin tectonics, and global thermal evolution to the major mascon maria – regions of the moon's crust which contain a large amount of material denser than average for that area (Solomon, Head, 1980).
Past studies (Budney, Lucey) revealed that craters in the mare Humorum sometimes excavate highland material, allowing to estimate the thickness from below the mare cover. Thanks to this, it was also possible to determine that the ‘multiring’ structure of the Humorum basin has a diameter of 425 kilometres (results based on the US Clementine global topography data).
In general, the chronology of lunar volcanism is based on the analysis of landing site samples from the Apollo and Luna missions, from the study of the relationship between the stratigraphy (layering of deposits) in different regions, and from the analysis of lunar craters – how they degraded over time and how their distribution in number and size varies over the Moon’s surface. From crater statistics, in the year 2000 Hiesinger and colleagues found that in Humorum there was a peak of eruptions at about 3.3-3.5 thousand million years ago.
|
|
33-SulpiciusGallus.jpgSulpicius Gallus' Region68 visiteThis mosaic of three images, taken by the advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows the area close to the Sulpicius Gallus crater on the Moon.
AMIE obtained this sequence on 18 March 2006, from a distance of 1200 kilometres from the surface, with a ground resolution ranging from 110 to 114 metres per pixel.
The area shown in the top image is centred at a latitude of 19.7º North and longitude 12.2º East; the image in the middle is centred at a latitude of 18.2º North and longitude 12.3º East; the bottom image is centred at a latitude of 16.7º North and longitude 12.5º East.
The prominent crater on the upper left area of this mosaic is called Sulpicius Gallus. It is a fairly fresh, bowl-shaped crater with a diameter of roughly 12 kilometres. The flat lava plains surrounding it belong to the Mare Serenitatis (the 'Sea of Serenity') on the north-eastern side of the Moon facing Earth. The mountains going diagonally through the middle part of the mosaic are called Montes Haemus. They are denoting the edge of the huge impact crater which formed the Mare Serenitatis.
The area around Sulpicius Crater is very interesting for lunar scientists – it is one of the most geologically and compositionally complex areas of the nearside of the Moon. The geologic history of this region has been shaped by impacts of different scales and epochs, by volcanism of variable style and composition with time, and by limited tectonics. Specific findings (Bell and Hawke, 1995) include the detection of relatively fresh highlands materials in the crater.
Good spectroscopic data (that is relative to the mineralogical composition) are available both from the Clementine mission and from ground-based observations, allowing to better constrain the geological evolution of our closest cosmic neighbour.
The area has been suggested to contain mixtures of glassy and black beads generated when large impacts melted part of the lunar surface. However, modelling the spectral properties of material similar to lunar material does not allow to unambiguously match the composition of the material to the measured data.
Colour observations of the AMIE camera will help in further clarifying these issues. So, the combination of high spatial resolution imaging and high spectral resolution spectroscopy from datasets from SMART-1, Clementine and ground based telescopes will finally allow to better model mineral mixtures on the Moon.
The crater Sulpicius Gallus is named after a Roman general, state man and orator. He is famous for having predicted an eclipse of the moon on the night before the battle of Pydna (168 BC). A man of great learning, in his later years he devoted himself to the study of astronomy.
|
|
34-Apollo 11 LS-1888_40L_Hi.jpgThe "Apollo 11 Landing Site"79 visiteCaption ESA originale:"This image, taken by the Advanced Moon Imaging Experiment (AMIE) on board ESA’s SMART-1 spacecraft, shows the Apollo 11 Landing Site in the Mare Tranquillitatis Region of the Moon.
AMIE obtained the image on 5 February 2006 from a distance of 1764 Km from the surface, with a ground resolution of 159 mt per pixel.
The imaged area is centred at a Long. of 23,9º East, close to the Moon Equator, at 1,7º North Latitude.
The area is close to crater Moltke (outside the field of view of this image) in the Mare Tranquilitatis Region. The arrow shows the Landing Site of Apollo 11, where the first men from Earth set foot on another object in our Solar System, on 20 July 1969. The two prominent craters nearby are named after two of the Apollo 11 Astronauts. The first man on the Moon, Armstrong, has a crater named after him outside the field of this image".
|
|
35-Lomonosov Crater-AMI_EAE3_001856_00042_00038.jpgLomonosov Crater76 visiteCaption ESA originale:"This image, taken by the Advanced Moon Imaging Experiment (AMIE) on board ESA’s SMART-1 spacecraft, shows crater Lomonosov, on the Moon’s Far (or "Dark") Side.
AMIE obtained the image on 30 January 2006 from a distance of about 2100 Km from the surface, with a ground resolution of 190 mt per pixel. The imaged area is centred at a Latitude of 27,8º North and a Longitude of 98,6º East.
Crater Lomonosov is a nice example for a large crater (92 Km of diameter) which was filled by lava after the impact, thus exhibiting a flat floor. The terraced walls indicate 'slumping', that is sliding of the rocks downwards due to gravity after the end of the impact. The small craters inside Lomonosov are the result of impacts into this lava floor which happened after the formation of Lomonosov".
|
|
36-AMI_EAE3_001775_00019_00020_H.jpgCrater Gruithuisen-B and Gruithuisen Montes65 visiteCaption ESA originale:"This image, taken by the Advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows the Gruithuisen Area on the Moon.
AMIE obtained this image on 1 January 2006, from a distance of about 2154 Km from the surface, with a ground resolution of 195 mt per pixel.
The area shown in the image is centred at a Latitude of 34.8º North and Longitude 40º West.
The prominent bowl-shaped crater close to the left edge of the image is Gruithuisen-B. Gruithuisen itself is just visible at the right edge of the image. The mountains visible in the area are called Montes Gruithuisen.
It is possible to note the large number of similar sized craters to the right of the centre of the image. They are so-called secondary craters, produced by ejecta particles from a large impact which fell back to the Moon".
|
|
36-Shackleton_Crater-AMI_EAE3_001775_00002_00020.jpgSchakleton Crater in natural colors59 visiteThe Advanced Moon Imaging Experiment Camera (AMIE) obtained this image on 13 January 2006 - close to the time of Lunar Southern Summer - from a distance of about 646 Km over the surface and with a ground resolution of 60 mt per pixel.
Shackleton crater lies at the Lunar South Pole (89,54° S. Lat. and 0° East Lng.) and has a diameter of approx. 19 Km.
SMART-1 monitored this area almost every orbit. This will allow to produce very high resolution maps of the area as well as illumination maps. The long shadows that surround the crater make it very hard to observe. The analysis of the data obtained allowed a very detailed map of its rim, surrounding ejectas and craters.
SMART-1 also made long repeated exposures to see inside the shadowed areas. The purpose was detecting the very weak reflected light from the crater rims, and therefore study the surface reflection properties (albedo) and its spectral variations (mineralogical composition). These properties could reveal patchy ice surface layers inside the crater.
On the 2-kilometre wide inner edge of the crater ridge, at times barely visible from Earth, astronomers using ground radio-telescopes have recently reported they were not able to detect a distinctive signature of thick deposits of ice in the area. Earlier measurements by NASA's Lunar Prospector reported of hydrogen enhancement over large shadowed areas.
"We still do not know if this hydrogen is due to enhanced trapping of solar wind, or to the water ice brought on the Moon by the bombardment of comets and asteroids," says Bernard Foing, ESA's SMART-1 Project Scientist. "These bodies may have deposited on the Moon patchy layers of ice filling about 1.5 percent of the areas in permanent shadow, down to one metre below the surface."
"We need to analyse all remote sensing data sets consistently. Future lander and rover missions to the Moon will help in the search and characterisation of lunar polar ice, both on the surface and below the subsurface," Foing continues. "In any case, one day we may even be able to simply combine the implanted hydrogen and the oxygen extracted from lunar rocks to produce clean water, like we do in laboratory experiments on Earth.”
The crater is named after Ernest Shackleton (1874-1922), an explorer famous for his Antartic expeditions.
MareKromium
|
|
37-AMI-Mersenius Crater.jpgMersenius "C"59 visiteCaption ESA originale:"This mosaic of 3 images, taken by the Advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows the crater Mersenius "C" on the Moon.
AMIE obtained this sequence on 13 January 2006, from distance of 1149, 1172 and 1195 Km from the surface, respectively. The ground resolution ranges from 104 to 108 mt per pixel. All images are located at a Long. of 45,7º West and at Lat. of 21,3º, 19,7º and 18,1º South, respectively.
For separate images go to:
AMI_EAE3_001777_00008_00020.JPG; AMI_EAE3_001777_00009_00020.JPG; AMI_EAE3_001777_00010_00020.JPG.
Crater Mersenius "C" is positioned in the highland area between Mare Humorum and the Oceanus Procellarum. The crater has a diameter of 14 Km and is best visible for ground-based observers 4 days after first quarter Moon".
|
|
40-Jacobi Crater.jpgJacobi Crater (HR)56 visiteThis HR image was taken by the advanced Moon Imaging Experiment (AMIE) on 18 March 2006 from a distance of about 578 Km from the Moon's surface, with a ground resolution of 52 mt per pixel. It shows part of crater Jacobi in the Moon's Southern Hemisphere. The western crater rim can be seen on the left edge of the image. The imaged area is centred at a Latitude of 56,5° South and a Longitude of 10,9° East, with a field of view of 27 Km. North is up.
Crater Jacobi itself is much larger than this image - 68 Km in diameter - with the imaged area only showing about 1/5th of the crater floor area. The crater is centred at a Latitude of 56,7° South and a Longitude of 11,4° East. The single prominent crater to the upper left of the image centre is Jacobi "W", with a diameter of only 7 Km.
Peculiar surface structure can be seen in the lower left part of the image, and indicates several heavily eroded big-sized craters.
SMART-1 resolution at high solar elevation angle allows for the detection of eroded structures buried under more recent layers, giving a window on the past evolution of the Moon.
The crater is named after the German mathematician Karl Gustav Jacob Jacobi (1804 - 1851), who worked on elliptic functions and was active in the field of celestial mechanics
|
|
41-Mezentzev Crater.jpgCraters Mezentsev, Niepce and Merril58 visiteThis image was taken by the Advanced Moon Imaging Experiment (AMIE) on 16 May 2006. The imaged area is centred at a Latitude of 73° North and a Longitude of 124° West, on the Far-Side of the Moon.
Normally, the AMIE camera is pointed straight down at the Lunar Surface, in the Nadir pointing mode. In this image, AMIE was pointed towards the horizon, showing the Lunar Surface in an oblique view.
The largest craters in this image are Mezentsev, Niepce and Merrill. Mezentsev is an eroded crater 89 Km in diameter and centred at 72,1° N, and 128,7° W.
A smaller cup-shaped crater resides inside Mezentsev. Niepce and Merrill both have a diameter of 57 Km and are located at 72,7° N-119,1° W and 75,2° N and 116,3° W, respectively.
Mezentsev Crater is named after Yourij Mezentsev, a Soviet engineer (1929 - 1965) who was one of the first people to design rocket launchers, while Joseph Niepce was the French inventor of photography (1765 - 1833); Paul Merrill was an American astronomer (1887 - 1961).
|
|
42-CuvierC-AMI_EAE3_002085_L,1.jpgCuvier "C"56 visiteCaption ESA originale:"This high-resolution image, taken by the Advanced Moon Imaging Experiment (AMIE) on board ESA’s SMART-1 spacecraft, shows the young crater ‘Cuvier C’ on the Moon.
AMIE obtained this sequence on 18 March 2006 from a distance of 591 Km from the surface, with a ground resolution of 53 mt per pixel. The imaged area is centred at a Latitude of 50,1º South and a Longitude of 11,2º East, with a field of view of 27 Km. The North is on the right of the image.
Cuvier "C", a crater about 10 Km across, is visible in the lower right part of the image. Cuvier "C" is located at the edge of the larger old crater Cuvier, a crater 77 Km in diameter. The upper left quadrant of the image contains the smooth floor of Cuvier, only one fourth of which is visible in this image".
|
|
50-Smart-1_25_August_1348UTC_H.jpgLunar Limb and Stars60 visiteCaption ESA originale:"This image of the Lunar Surface was taken on 25 August 2006 at 15:48 CEST (13:48 UT) by the star tracker (attitude camera) on board ESA's SMART-1, from a distance of 744 Km above the Moon surface.
The spacecraft was travelling at a speed of 1,6 Km/sec..
Remarkably, at the time the image was taken the star tracker was still producing valid attitude samples based on the few stars that are visible in the image.
This image was taken as a test, meaning that the spacecraft pointing was not optimised for star tracker imaging.
The Moon features on the photo still have to be identified".
|
|
| 75 immagini su 7 pagina(e) |
|
|
4 | |
|
|
|
|
