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ZZ-Mercury-Craters-Crater_Field-208852.jpgFresh Primary Impact Crater and Secondary Craters (HR)54 visiteOn January 14, 2008, NASA’s MESSENGER spacecraft observed about half of the hemisphere not seen by Mariner 10. This image shows part of a large, fresh crater with secondary crater chains located near Mercury’s Equator on the side of the Planet newly imaged by MESSENGER.
Large, flat-floored craters show terraced rims from post-impact collapse of their newly formed walls. The hundreds of secondary impactors that are excavated from the Planet’s surface by an incoming object, create long, linear crater chains radial to the main crater.
These chains, in addition to the rest of the ejecta blanket, create the complicated, hilly terrain surrounding the primary crater in the image. By counting craters that have formed since the impact event, the age of the crater can be estimated.
This count can then be compared with a similar count for the crater floor to determine whether any material has partially filled the crater since its formation. With their large size and production of abundant secondary craters, these flat-floored craters both illuminate and confound the study of the geological history of Mercury. MareKromium
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ZZ-Mercury-Craters-Crater_Field-PIA13823-1.jpgSome Mercurian Surface Features explained (False Colors; credits: 54 visiteCaption NASA:"During MESSENGER's second Fly-By of Mercury, MDIS acquired a strip of HR images obtained with each of the WAC's 11 different color filters. The graphic shown here displays the resulting enhanced-color mosaic and gives considerable detail about the images, how the mosaic was created and the Geologic Features that can be seen.
Currently, these images are the Highest-Resolution color images ever obtained of the Solar System's innermost Planet, but not for long! On March 18, 2011, MESSENGER will enter into orbit about Mercury and the mission's extensive, year-long science observation campaign will begin.
That campaign includes capturing color images of Mercury's Surface at higher resolution than ever before".MareKromium
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ZZ-Mercury-Craters-Crater_Field-PIA13823-2-PCF-LXTT_(2).jpgThe Surface of Mercury (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)92 visitenessun commentoMareKromium
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ZZ-Mercury-Craters-Crater_Field.jpgChangings...54 visiteDate Acquired: October 6, 2008
Image Mission Elapsed Time (MET): 131774145
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 550 meters/pixel (0,34 miles/pixel)
Scale: Asvaghosa crater is approx. 90 Km in diameter (about 56 miles)
Spacecraft Altitude: about 21.000 Km (approx. 13.000 miles)
Of Interest: This pair of images illustrates the dramatic effect that illumination and viewing geometry (i.e., the angle at which Sunlight strikes the surface, and the angle from which the spacecraft views the surface) has on the appearance of terrain on Mercury. The image on the right is a frame captured by MESSENGER’s NAC as the spacecraft was departing the planet after its second Mercury flyby. On the left is a portion of a mosaic made from Mariner 10 clear-filter images, obtained by that mission in 1974. The yellow arrows point to the 90-Km- (56-mile-) diameter crater Asvaghosa (named for the first century AD Indian philosopher and poet), and the purple arrows indicate a smaller crater to the southwest. A bright ray, prominently visible in the high-Sun MESSENGER frame, crosses both craters. The stripe of high-reflectance material may have originated at Kuiper crater (to the southwest) or may come from a newly imaged crater to the northeast that has an extensive ray system. This ray and others seen in the NAC image were mostly invisible to Mariner 10, because low-Sun illumination emphasizes topography instead of differences in reflectance. As another example, the curving scarp (cliff) named Santa Maria Rupes (white arrows in the left image) is visible in the Mariner 10 image by the shadow it casts, but this rupes disappears in the MESSENGER image when the Sun is high overhead. Images collected under both high- and low-Sun conditions are needed for geologists to develop a complete understanding of the features on a planetary surface.MareKromium
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ZZ-Mercury-Craters-Cratered_Plains-PIA12050.jpgRudaki Plains and Crater54 visiteLast week (April 2009), MESSENGER team members presented the results from 4 papers published in the 1st of May issue of the "Science" magazine at a NASA media teleconference. The color views shown here of the Plains near Rudaki Crater was just one of the graphics presented at that teleconference (nota: NO. La versione che vedete su queste pagine è quella ottenuta da Lunar Explorer Italia, applicando la metodologia Multispettrale).
The left image was created by combining WAC images from three narrow-band color filters to approximate Mercury's color as it would be seen by the human eye. The right image used a statistical analysis of all 11 WAC filters to highlight subtle color differences on the surface, as has been used for many previous releases, such as ones focused on Thakur Crater and Caloris Basin.
Date Acquired: October 6, 2008
Image Mission Elapsed Time (MET): 131770571-131770621
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS).
WAC Filters: Left image: 3, 4, 5 (480, 560, 630 nanometers). Right Image: statistical analysis involving all 11 WAC filters
Scale: The crater in the center of the image is approx. 68 Km (about 42 miles) in diameter
Spacecraft Altitude: about 2800 Km (approx. 1700 miles)MareKromium
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ZZ-Mercury-Craters-Damer_Crater-PIA17812-PCF-LXTT-IPF.jpgThe Walls of Damer (Absolute Natural Colors; credits for the additional process. and color. Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)55 visiteThe (relatively) steep Walls of the Impact Crater named Damer are well highlighted in today's APOD. Named after the English sculptor, Anne Seymour Damer (née Conway, she was born in Sevenoaks - UK - on November, 8, 1749 and died in London on May, 28, 1828) earlier this year by the International Astronomical Union (or "IAU", for short), this approx. 60-Km diameter (such as about 37,26 miles) Impact Crater is distinguished by a massive and complex Central Peak that is almost completely covered with Hollows.
Date acquired: November, 13th, 2013
Images Mission Elapsed Time (MET): 26687033
Images ID: 5191249
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 36,25° North
Center Longitude: 243,40° East
Solar Incidence Angle: 68,3° (meaning that the Sun, at the time that the picture was taken, was about 21,7° above the imaged Local Mercurian Horizon)
Emission Angle: 3,0°
Sun-Mercury-Messenger (or "Phase") Angle: 65,3°
This frame (which is an Original NASA - MESSENGER Spacecraft's b/w and NON Map-Projected image-mosaic published on the NASA - Planetary Photojournal with the ID n. PIA 17812) has been additionally processed, contrast enhanced, magnified to aid the visibility of the details, Gamma corrected and then colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - MESSENGER Spacecraft and then looked down, towards the Western Edge of the Mercurian Impact Crater "Damer"), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among other things, the existence of different Elements (Minerals) present on the Surface of Mercury, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
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ZZ-Mercury-Craters-DeGas-PCF-LXTT.jpgBright-white Deposits inside Degas Crater (Absolute Natural Colors; credits for the additional process. and color: Dr Paolo C. Fienga - Lunexit Team)63 visitenessun commentoMareKromium
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ZZ-Mercury-Craters-Dearin_Crater-PIA13488.jpgDark Spot at "Derain Crater" (Enhanced Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)116 visiteIn the center of this image is Derain, an impact crater first viewed during MESSENGER's 2nd Mercury flyby and named in 2009.
Derain has material within it and in its surroundings that is much darker than the neighboring terrain. In fact, the material associated with Derain appears to have the lowest reflectance yet identified on Mercury's Surface.
The Dark Deposits may be material with a mineralogical composition different from the majority of Mercury's visible Surface, but more data are needed before any further insight into the composition can be gained.
Observations to be acquired during MESSENGER's orbital mission phase will help to identify the uncommonly Dark Material at Derain Crater and similar occurrences elsewhere on the Planet.
Also visible in this image (upper right side), is the rayed Crater "Berkel", which has Dark Material as well in its center and in a ring immediately surrounding it. In contrast, two neighboring craters of Berkel have bright rays but lack Dark Halos. Why do some craters contain Dark Materials while others do not? MESSENGER's orbital data will be used to investigate that question and to improve our understanding of the nature and structure of Mercury's Crust.
Date Acquired: October 6, 2008
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Scale: Derain Crater is approx. 190 Km in diameter (such as about 118 miles)MareKromium
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ZZ-Mercury-Craters-Debussy_Crater-PIA14080-PCF-LXTT.jpgRays from Debussy Crater (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)135 visiteBright Rays, consisting of Impact Ejecta and Secondary Craters, spread across this NAC image and radiate from Debussy Crater, located at the top. The image, acquired during the first orbit for which MDIS was imaging, shows just a small portion of Debussy's large System of Rays in greater detail than ever previously seen. Images acquired during MESSENGER's second Mercury Fly-By showed that Debussy's Rays extend for hundreds of Km across Mercury's Surface. Debussy Crater was named in March 2010, in honor of the French composer Claude Debussy (1862-1918).
Date Acquired:March 29, 2011
Image Mission Elapsed Time (MET):209885555
Image ID:65082
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 36,4° South
Center Longitude: 16,1° East
Resolution: approx. 300 mt/pixel (0,19 miles/pixel)
Scale: Debussy Crater has a diameter of about 80 KmMareKromium
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ZZ-Mercury-Craters-Donalaitis_Crater-PIA16958-PCF-LXTT-IPF-1.jpgDonelaitis Crater (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/IPF)113 visiteThis composite of three frames, taken by the NASA - MESSENGER Spacecraft in August 2011, shows us the recently named Donalaitis Crater (whose diameter is approx. 84,5 Km - such as about 52,47 miles - and it lies well visible at the center of the image). As you can see, this Complex Mercurian Impact Crater exhibits some extremely unusually-looking bright yellow-orangish Deposits on its Floor. These colorful and very bright Deposits, as you may easily notice, contrast starkly with the much darker and gray colors (with pale brown/reddish nuances and some brighter white spots - where the latter could be, perhaps, some Hollows-covered areas) of the surrounding (and highly cratered) Terrain.
Donelaitis Crater was named after Kristijonas Donelaitis (1714 - 1780), a Lithuanian poet. His classic poem, 'The Seasons (Metai)', describes the lives of Lithuanian peasants, who at the time of its writing were being pushed into serfdom as most of their country was annexed by the Russian Empire.
Date acquired: August, 21st, 2011
Images Mission Elapsed Time (MET): 222408661, 222408681, 222408665
Images ID: 658976, 658981, 658977
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 51,81° South
Center Longitude: 39,11° East
Resolution: 874 meters/pixel
Solar Incidence Angle: 56,2° (meaning that the Sun, at the time that the picture was taken, was about 33,8° above the imaged Local Mercurian Horizon)
Emission Angle: 0,5°
Sun-Mercury-Messenger (or "Phase") Angle: 55,7°
This picture (which has been cropped from an Original NASA - MESSENGER Spacecraft false color image-mosaic published on the NASA - Planetary Photojournal with the ID n. PIA 16958) has been additionally processed and then colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - MESSENGER Spacecraft and then looked down, towards the Surface of Mercury), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among other things, the existence of different Elements (Minerals) present on the Surface of Mercury, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
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ZZ-Mercury-Craters-Eitoku_Crater-PIA16361-PCF-LXTT.jpgEitoku Crater (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)70 visiteThe main and really impressive Impact Crater visible in this NASA - MESSENGER Spacecraft image, Eitoku (which has a diameter of approx. 100 Km - such as about 62 miles) , displays several (almost) Central Peaks that appear especially prominent due to the high Solar Incidence Angle (meaning that the Sun was setting onto the imaged Local Horizon at the time that this picture was taken - and therefore the shadows of each and every Mercurian relief resulted way more visible - i.e.: longer - and suggestive) as well as to the fact that this frame has not been Map Projected. Note that Central (and/or almost Central, like in this case) Peaks are a relatively common Feature in Mercury's larger Impact Craters. Note, also, that the smaller Impact Craters visible on the Floor and Rim (which, on its side, appears quite degraded) of Eitoku Crater indicate/suggest that we are actually looking at an old Impact Feature.
Date acquired: July, 3rd, 2012
Image Mission Elapsed Time (MET): 249790754
Image ID: 2129670
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 21,77° South
Center Longitude: 202,6° East
Resolution: 120 meters/pixel
Solar Incidence Angle: 83,4° (meaning that the Sun, at the time that the picture was taken, was about 6,6° above the imaged Local Mercurian Horizon)
Emission Angle: 59,9°
Sun-Mercury-Messenger (or "Phase") Angle: 134,5°
This picture (which is an Original NASA - MESSENGER Spacecraft color frame published on the NASA - Planetary Photojournal with the ID n. PIA 16361) has been additionally processed and then colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - MESSENGER Spacecraft and then looked down, towards the Surface of Mercury), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among other things, the existence of different Elements (Minerals) present on the Surface of Mercury, each having a different Albedo (---> Reflectivity) and Chemical Composition.MareKromium
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ZZ-Mercury-Craters-Eminescu_Crater-PIA10610.jpgEminescu Crater (MULTISPECTRUM-2; credits: Lunexit)54 visiteLast week, the MESSENGER team learned that the impact crater seen in the middle of this Narrow Angle Camera (NAC) image has been officially named Eminescu. The Crater was named in honor of Mihai Eminescu, an accomplished and influential poet who is still considered the national poet of Romania. The MESSENGER team proposed the name to the International Astronomical Union (IAU), the authority that officially names surface features on planetary bodies.
Eminescu Crater is 125 Km (about 78 miles) in diameter and can be seen just at the top of PIA10384.
The image shown here was acquired by the Mercury Dual Imaging System (MDIS) on January 14, 2008, and shows a portion of Mercury's surface unseen by spacecraft prior to MESSENGER's historic flyby.
Eminescu is a particularly interesting crater for several reasons. Eminescu formed more recently than most of the craters on Mercury, on the grounds that there are very few later craters superposed on it. Moreover, impressive chains of secondary craters, formed by material ejected by the impact explosion that formed the crater, radiate away from Eminescu.
The central peaks within the crater are arranged in a circular pattern; geologists call this a "Peak Ring".
The bright peaks inside Eminescu exhibit unusual color characteristics in the 11-color Wide Angle Camera (WAC) images, which the MESSENGER Science Team is currently studying.
They show up with a bluish tinge in the previously released false-color image of the entire planet (see PIA10398); Eminescu is just North of the Equator, near the day/night "Terminator" in that image.MareKromium
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