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| Piú votate - Mercury |
ZZ-Mercury-Natural_Satellite-Caduceus-PIA15542.jpgNOT ALONE!239 visiteCaption NASA:"This discovery image provides the first evidence that Mercury has a small natural satellite or moon. Visible as a small bright spot in an image taken yesterday by the Mercury Dual Imaging System (MDIS) Wide Angle Camera (WAC), the moon is approximately 70 meters (230 feet) in diameter and orbits Mercury at a mean distance of 14.300 Km (such as 8890 miles). A proposal to name the moon "Caduceus", after the staff carried by the Roman god Mercury, has been submitted by the MESSENGER team to the International Astronomical Union, the body responsible for assigning names to celestial objects.
This discovery presents an unprecedented opportunity for a return of samples from the Mercury System, as Project Scientist Nat MacRulf explains. "We have yet to identify a sample from Mercury in any of the meteorite collections we have here on Earth. Such a sample would give us critical insight into the chemical composition of Mercury and the timing of crustal formation on that body, leading to a better understanding of how the planet formed and evolved. If we could obtain a sample of Caduceus, it would enhance the scientific return of the MESSENGER mission beyond our wildest dreams!"
Work on designing a scenario for sample return is already underway. MESSENGER Project Manager Burt Panini held an emergency meeting with the MESSENGER mission operations and navigation teams yesterday evening to determine if the spacecraft could be targeted toward the diminutive moon. After an intensive discussion, a unanimous decision was taken to abandon the orbit-correction maneuvers that had been planned for later this month to place the spacecraft in an eight-hour orbit. Instead, the new plan is to use the remaining propellant to crash MESSENGER into Caduceus. "Our detailed analysis tells us that if we act now, and with the right trajectory, MESSENGER will impart just enough momentum to the moon to break it free of Mercury's Gravity well and set it on an Earth-crossing trajectory suitable for recovery as a Mercury meteorite", said Panini.
This action will form the basis of a new request to NASA by the MESSENGER team for an extended extended mission, tentatively called "MESSENGER Infinitesimally Nudging Caduceus", or MIN-C for short. Once MIN-C is approved by NASA, the Spacecraft will be targeted for a collision trajectory. If Caduceus is successfully released from the pull of Mercury and placed on a course to reach Earth, we can expect the moon to arrive at Earth by 2014. "The risk to the public is reassuringly small", offers MESSENGER mission design lead Adam McJames. "We have designed a trajectory that will bring the moon to Earth at a remote location on the Wilkes Land ice sheet in Antarctica. This trajectory will avoid all population centers and will put the moon's impact site within reach for retrieval by the scientific staff at the U.S.-operated McMurdo Station".
If successful, MESSENGER's extended extended MIN-C mission will mark the first instance of the documented arrival to Earth of material from the Mercury system. Moreover, it will serve as the basis for a new Discovery-class mission proposal currently in development by the Applied Psychics Laboratory for a Mercury lander mission for in situ X-ray analysis of surface composition. That mission is to be named the Hermean On-surface Analysis with X-rays.
Date acquired: March 31, 2012
Image Mission Elapsed Time (MET): 131766564
Image ID: 6418
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 38,15° North
Center Longitude: 66,18° East
Resolution: 410 meters/pixel (0,25 miles/pixel) in the lower left corner of the image
Scale: the large crater in the center of the image (Copland) is about 210 Km (such as approx. 130 miles) in diameter.
Spacecraft Altitude: 16.200 Km (10.070 miles)
Incidence Angle: 69,1°
Emission Angle: 80,8°
Phase Angle: 138,2°MareKromium
(7 voti)
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ZZ-Mercury-Volcanic_feature-Collapse_Pit-PIA13468-PCF-LXTT.jpgCollapse Pit-Chain inside Picasso Crater (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)202 visiteThe Crater pictured in the center of this image was recently named Picasso, in honor of the Spanish painter and sculptor Pablo Picasso (1881-1973). This Crater, first imaged during MESSENGER's third Mercury Fly-By, has drawn scientific attention because of the large, arc-shaped Pit-Chain located on the Eastern side of its Floor. Similar Pits have been discovered on the Floors of several other Mercurian Craters, such as Beckett and Gibran. These Pits are postulated to have formed when subsurface magma subsided or drained, causing the surface to collapse into the resulting void. If this interpretation is correct, Pit-Floor Craters - such as Picasso - provide evidence of shallow magmatic activity in Mercury's history.
Date Acquired: September 29, 2009
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 500 meters/pixel (0,31 miles/pixel)
Scale: the diameter of Picasso is roughly 133 Km (about 83 miles)
Projection: This image is a portion of the NAC approach mosaic from Mercury Fly-By n. 3. It is shown in a simple cylindrical map projection.MareKromium
(7 voti)
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ZZ-Mercury-Craters-Unnamed_Craters-PIA14191-PCF-LXTT.jpgUnnamed Craters (Absolute Natural Colors; credits for the additional process. and color: Dr Paolo C. Fienga - Lunexit Team)181 visiteImage Mission Elapsed Time (MET): 209889250
Image ID: 65107
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 1,7° North
Center Longitude: 354,3° East
Resolution: approx. 246 mt/pixel
Scale: this image is approx. 390 Km acrossMareKromium
(7 voti)
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ZZ-Mercury-Craters-Unnamed_Southern_Rayed_Crater-PIA11371.jpgSpectacular "Rayed-Crater" (Enhanced Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)72 visiteThis NAC image shows a bright crater with an extensive system of impact ejecta rays; the crater is also clearly visible on the Southern portion of Mercury near the Limb of the Planet in the departure full-planet image (see PIA11245).
This impact crater and its associated system of rays were originally detected in 1969 as a “bright feature” in radar images at 12,5-centimeter wavelength obtained by the Goldstone Observatory in California. Subsequently, about a decade ago, radar images acquired by the Arecibo Observatory in Puerto Rico clearly revealed this feature to be a crater with a fresh system of rays of rough material radiating outward from it. This feature has been referred to simply as Feature “A”.
MESSENGER’s recent Mercury flyby provided the first Spacecraft images of Feature “A”, enabling this relatively young crater with its impressive set of rays to be seen here in close-up detail.
Date Acquired: October 6, 2008
Image Mission Elapsed Time (MET): 131773947
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 530 meters/pixel (0,33 miles/pixel)
Scale: The bright rayed crater is approx. 80 Km (about 50 miles) in diameter
Spacecraft Altitude: approx. 20.600 Km (about 12.800 miles)MareKromium
(7 voti)
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ZO-Mercury-Flyby2_Messenger_big.jpgMercury as Revealed by MESSENGER (Enhanced Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)66 visiteCaption NASA:"The Planet Mercury has been known since history has been recorded, but parts of the Solar System's Innermost Planet have never been seen like this before. Two days ago the robotic MESSENGER Spacecraft buzzed past Mercury for the second time and imaged terrain mapped previously only by comparatively crude radar.
The above image was recorded as MESSENGER looked back 90 minutes after passing, from an altitude of about 27.000 Km. Visible in the above image, among many other newly imaged features, are unusually long rays that appear to run like meridians of longitude out from a young crater near the northern limb.
MESSENGER is scheduled to fly past Mercury once more before firing its thrusters to enter orbit in 2011".MareKromium
(7 voti)
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ZO-Mercury03_Messenger-208855main_half_merc_350.jpgCrescent Mercury65 visiteAs NASA’s MESSENGER neared Mercury on January 14, 2008, the Spacecraft took this image of the Planet’s full crescent.
The image shows portions of Mercury previously seen by Mariner 10, but when Mariner 10 flew by the Planet at each of its encounters, the Sun was nearly overhead. For this MESSENGER flyby, in contrast, the Sun is shining obliquely on Regions near the day/night boundary (called the Terminator) on the right-hand side of the crescent, revealing the surface topography.
This image illustrates how MESSENGER, during its future flybys and subsequent orbital mission, will teach scientists much about the portion of Mercury already imaged by Mariner 10.MareKromium
(7 voti)
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ZZ-Mercury-Craters-Waters_Crater-PIA18228-PCF-LXTT-IPF.jpgWaters Crater (EDM - Possible Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)124 visiteIn this beautiful image, obtained by the NASA - MESSENGER Spacecraft on September, 16, 2013, we can see the extremely unusually-looking Impact Crater known as Waters. The South-heading Dark Impact Melt Flow of Waters Crater (approx. 15 Km - such as about 9,315 miles - in diameter and so named, in the AD 2012, after the blues legend Muddy Waters - Mc Kinley Morganfield, born in Issaquena County - Mississippi - USA -, on April 4, 1913 and deceased in Westmont, Illinois, on April 30, 1983) has always been - we'd say, obviously - a Surface Feature of great interest for Planetary Scientists, and the Targeted Color Imaging Campaign carried out by the NASA - MESSENGER Spacecraft showed quite well, and more than once, the distinctive dark gray-greenish-bluish color of the aforementioned Impact Melt Flow.
As a consequence of such a great interest, during the late AD 2013, this High-Resolution Image was then acquired, and it revealed stunning new details (like the Wavy Texture) of the Impact Melt Flow - details which were (as far as their visual quality was and is concerned) way beyond the ones that had been photographed in other (previous) frames.
Date acquired: September, 16th, 2013
Image Mission Elapsed Time (MET): 21673915
Image ID: 4834878
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 9,00° South
Center Longitude: 254,70° East
Solar Incidence Angle: 44,0° (meaning that the Sun, at the time that the picture was taken, was about 46,0° above the imaged Local Mercurian Horizon)
Emission Angle: 44,8°
Sun-Mercury-Messenger (or "Phase") Angle: 85,5°
This picture (which is an Original NASA - MESSENGER Spacecraft's b/w and NON-Map-Projected image published on the NASA - Planetary Photojournal with the ID n. PIA 18228) has been additionally processed, contrast enhanced, Gamma corrected, magnified to aid the visibility of the details 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 outside, 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
(6 voti)
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ZZ-Mercury-Craters-Unnamed_Craters-PIA15857-PCF-LXTT-IPF.jpgCraters on the Mercurian Terminator (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)128 visiteThis is a beautiful and dramatic image of the Surface of Planet Mercury that was taken by the NASA - MESSENGER Spacecraft just when the Sun was a mere 10 degrees above the Local (imaged here) Horizon. The frame shows us four (4) Simple Unnamed Impact Craters which are all located on top of the Rim of a larger (approx. 3 Km-diameter) Simple Unnamed Crater (look from about 12 to a little after 1 o' clock of the disc drawn by the larger Crater) which, on its side, is positioned on the Outer Rim of an even larger (such as approx. 35 Km-diameter) Unnamed Complex Impact Crater which has been already caught and flooded by the shadows of the Mercurian Night.
As a matter of fact, the Rims of the four small Impact Craters show almost no signs of Erosion, or Collapse, and this circumstance marks them (always relatively speaking) as "young" Surface Features. However, while almost the entire Surface of Mercury is covered by Chains of small Craters (mostly formed by the action of repeated "waves" of Ejecta Boulders), these four small Craters DO NOT form nor constitute what is technically defined as a "Chain of Craters".
This image was acquired as a High-Resolution Targeted Observation. Targeted Observations are images of a small area on Mercury's Surface at resolutions much higher than the usual 200-meters per pixel Morphology Base Map. It is not possible to cover all of Mercury's Surface at such an High Resolution, but typically several areas of remarkable scientific interest are imaged in this mode each week.
Date acquired: May, 2nd, 2012
Image Mission Elapsed Time (MET): 217183900
Image ID: 1750578
Instrument: Narrrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 79,27° North
Center Longitude: 232,13° East
Resolution: 15 meters/pixel
Solar Incidence Angle: 79,8° (meaning that the Sun, at the time that the picture was taken, was about 10,2° above the Local Mercurian Horizon)
Emission Angle: 11,9°
Sun-Mercury-Messenger (or "Phase") Angle: 67,9°
This frame (which is an Original NASA - MESSENGER Spacecraft image published on the NASA - Planetary Photojournal with the ID n. PIA 15857) 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 the Planet 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
(6 voti)
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ZZ-Mercury-Craters-Unnamed_Crater_with_Rays-PIA14085-PCF-LXTT.jpgRelatively "Fresh" Impact Crater (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)201 visiteDate Acquired: March 29, 2011
Image Mission Elapsed Time (MET): 209894125
Image ID: 65182
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 11.8° North
Center Longitude: 13,9° East
Resolution: 160 mt/pixel
Scale: the bright Unnamed Crater is about 6,4 Km in diameter.MareKromium
(6 voti)
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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)143 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
(6 voti)
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ZZ-Mercury-Limb-PIA14190-PCF-LXTT-0.jpgMercurian Limb165 visiteImage Mission Elapsed Time (MET): 209890193, 209890197, 209890213
Image ID: 65109, 65110, 65114
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 6,7,9 (433, 749, 996 nanometers wavelength)
Center Latitude: 3,1° North
Center Longitude: 352,3° East
Resolution: approx. 1,5 Km/pixel
Nota Lunexit: abbiamo operato una leggerissima saturazione del frame NASA-Original per evidenziare come una "fetta" (decisamente abbondante) del frame - "fetta" relativa allo Spazio circum-Mercuriano - SEMBRA essere stata, di fatto, rimossa (od oscurata). Sia detto con chiarezza: questo è quello che appare dalla semplice analisi del frame, una volta operata - ripetiamo - una leggerissima "schiaritura" (over-saturation) dell'immagine. Quali i motivi di questa operazione di make-up (se di make-up effettivamente si trattasse)? Non ne abbiamo idea. Ma le Vostre opinioni al riguardo saranno, come sempre, apprezzate.MareKromium
(6 voti)
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ZZ-Mercury-Caloris_Basin-PIA13675-PCF-LXTT-3.jpgCaloris Basin (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)147 visiteThis view is a mosaic of multiple MDIS images and shows the Caloris Basin in its entirety. The Caloris Basin was discovered in 1974 from Mariner 10 images, but when Mariner 10 flew-by Mercury, only the Eastern half of the Basin was in daylight. During MESSENGER's first Mercury flyby, the Spacecraft was able to acquire High-Resolution images of the entire Basin, revealing the full extent of this Great Basin for the first time.
Geologists use the term "Basin" to refer to an impact crater that is larger than about 300 Km (186,3 miles) in diameter and often displays multiple Concentric Rings. Caloris has one Main Topographic Ring (1550-Km diameter). Patterns of concentric structures both inside and outside the Main Ring have been mapped and interpreted as evidence for additional Rings.
Caloris is one of the largest Impact Basins in the Solar System, and MESSENGER's orbital observations will provide much more data for this impressive geologic feature, including high-resolution color and low-Sun images for discerning morphology. This mosaic was obtained when the Sun was high overhead. Such lighting conditions emphasize brightness differences among the Surface Materials, with little shadowing to provide a sense of the texture and topography.
The interior of the Basin has been filled with lighter-hued Plains, which in turn have been modified by Impact Craters. These Craters range from small bright dots to larger Craters with bright Rays. Some of the larger Craters exhibit dark Rims. The dark Rims suggest that dark material underlies the Interior Plains in some places and was exposed through the formation of those Impact Craters.
Date Acquired: January, 14th, 2008
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Scale: Caloris Basin is roughly 1550 Km in diameter (about 962,55 miles)MareKromium
(6 voti)
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