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![Nome del file=B-Mercury-PIA02418.jpg
Dimensione del file=84KiB
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Aggiunta il=Gen 31, 2005 B-Mercury-PIA02418.jpg](albums/userpics/10008/small_B-Mercury-PIA02418.jpg)
B-Mercury-PIA02418.jpgMercury: the "outgoing" hemisphere53 visiteCaption NASA originale:"This mosaic shows the planet Mercury as seen by Mariner 10 as it sped away from the planet on March 29, 1974. The mosaic was made from over 140 individual TV frames taken about two hours after encounter, at a range of 37.300 miles (60.000 Km ). North is at top. The limb is at right, as is the illuminating sunlight. The equator crosses the planet about two-thirds of the way from the top of the disc. The terminator - such as the line-separating day from night - is about 190° West longitude. The planet shows a gibbous disc-more than half-illuminated. This hemisphere is dominated by smooth plains, rather than heavily cratered terrain, and resembles portions of the Moon's maria in general shape. Half of a very large, multi-ringed basin named Caloris Basin appears near the center of the disc near the terminator. Its surrounding mountain ring is 800 miles (1.300 Km) in diameter".
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![Nome del file=B-A-Mercury-PIA02961.jpg
Dimensione del file=158KiB
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Aggiunta il=Mar 20, 2006 B-A-Mercury-PIA02961.jpg](albums/userpics/10008/small_B-A-Mercury-PIA02961.jpg)
B-A-Mercury-PIA02961.jpgMercury, in HR54 visiteCaption NASA originale:"Taken only minutes after Mariner 10 made its closest approach to the planet Mercury on March 29, 1974, this is one of the highest resolution pictures obtained during the Mission. Craters as small as 150 mt (roughly 500 feet) across can be seen. The picture, taken from a distance of about 5900 Km (such as approx. 3700 miles), measures 50 by 40 Km (such as approx. 931 by 25 miles). The relativity level surface contrasts with the abundant relief seen in some close-up views on the opposite side of the planet. The long, narrow area of hills and scarps to the left resembles ridges in the mare of Earth's Moon. Abundant craters in various stages of degradation dot the surface".
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![Nome del file=ZZ-Mercury-Limb-CW0131772818A_web.jpg
Dimensione del file=313KiB
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Aggiunta il=Ott 17, 2008 ZZ-Mercury-Limb-CW0131772818A_web.jpg](albums/userpics/10060/small_ZZ-Mercury-Limb-CW0131772818A_web.jpg)
ZZ-Mercury-Limb-CW0131772818A_web.jpgMercury, during MESSENGER's 2nd Fly-By (natural, but enhanced colors; credits: Lunexit)53 visiteDate Acquired: October 6, 2008
Image Mission Elapsed Time (MET): 131772818
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC Filter: 1 (700 nanometers)
Resolution: 2,6 Km/pixel (about 1,6 miles/pixel)
Scale: The left side of the image is about 2700 Km tall (approx. 1700 miles)
Spacecraft Altitude: about 15.000 Km (approx. 9300 miles)
Of Interest: One week ago, no spacecraft had ever seen the majority of the surface visible in this image. Today, one week after MESSENGER’s successful second Mercury flyby, about 95% of Mercury’s surface has been viewed by spacecraft, resulting in nearly global spacecraft imaging coverage of Mercury’s surface for the first time. This WAC image is just one of 99 in a set of 3 columns by 3 rows by 11 color filters that is being combined into a color mosaic of the departing planet. Kuiper crater, with its bright ejecta rays, is visible on the left edge of the image and was seen by Mariner 10, but most of the terrain east of Kuiper was not. A newly imaged crater with an unusual halo of dark material is visible at about the same latitude but toward Mercury’s limb. The long, bright rays that can be seen extending across the surface emanate from a crater just north of this image.MareKromium
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![Nome del file=B-Mercury-PIA02411.jpg
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Aggiunta il=Gen 31, 2005 B-Mercury-PIA02411.jpg](albums/userpics/10008/small_B-Mercury-PIA02411.jpg)
B-Mercury-PIA02411.jpgMercury's "Kuiper Crater"60 visiteCaption NASA originale:"The Mariner 10 Television-Science Team has proposed the name "Kuiper" for this very conspicuous bright Crater (top center) on the rim of a larger older crater.
Prof. Gerard P. Kuiper, a pioneer in planetary astronomy and a member of the Mariner 10 TV team, died December 23, 1973, while the spacecraft was en route to Venus and Mercury. Mariner took this picture (FDS 27304) from about 88.450 Km (55.000 miles), some 2 1/2 hours before it passed Mercury on March 29, 1974. The bright-floored crater, 41 Km (25 miles) in diameter, is the center of a very large bright are which could be seen in pictures sent from Mariner 10 while Mercury was more than two million miles distant. The larger crater is 80 Km (50 miles) across".
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![Nome del file=ZF-Mercury_s South Pole-PIA02415_modest.jpg
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Aggiunta il=Set 12, 2004 ZF-Mercury_s South Pole-PIA02415_modest.jpg](albums/userpics/10008/small_ZF-Mercury_s%20South%20Pole-PIA02415_modest.jpg)
ZF-Mercury_s South Pole-PIA02415_modest.jpgMercury's South Pole64 visite3) vaporizzazione delle rocce causata da impatti con altri corpi celesti (meteore o comete).
Ma leggiamo ora cosa ci dice la NASA a proposito del fly-by del Mariner 10 nei pressi del suo Polo Sud: "...After passing Mercury the first time and making a trip around the Sun, Mariner 10 again flew by Mercury on September 21, 1974. This encounter brought the spacecraft in front of Mercury in the southern hemisphere. In this frame south is down, the South Pole is located on the right hand edge of the large crater that has only its rim sticking up into the light ("Chao Meng Fu" crater). When this frame was acquired, Mariner 10 was about 83.000 Km from Mercury".
Un'ultima annotazione riguarda i gas presenti nella sottilissima esosfera di Mercurio. Non possiamo parlare di un'atmosfera vera e propria poichè le molecole dei vari elementi che si trovano intorno al Pianeta sono così poche che non riescono neppure a collidere fra loro, come invece accade su Venere, Marte e la Terra stessa, ma si limitano a "rimbalzare" sulla sua superficie!
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![Nome del file=ZZ-Mercury-Cliffs-209522.jpg
Dimensione del file=711KiB
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Aggiunta il=Feb 02, 2008 ZZ-Mercury-Cliffs-209522.jpg](albums/userpics/10060/small_ZZ-Mercury-Cliffs-209522.jpg)
ZZ-Mercury-Cliffs-209522.jpgMercury's Long Cliffs53 visiteAs the MESSENGER team continues to study the HR images taken during the Mercury flyby encounter on January 14, 2008, scarps (cliffs) that extend for long distances are discovered. This frame, taken by the Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS), shows a Region of Mercury's surface previously unseen by spacecraft and a large scarp crossing vertically through the scene, on the far right of the image. This scarp is the northern continuation of the one seen in the NAC image released on January 16. The width of this image is about 200 Km (approx. 125 miles), showing that these scarps can be hundreds of kilometers long on Mercury.
The presence of many long and high scarps, as discovered from pictures from the Mariner 10 Mission in 1974 and 1975, suggests a history for Mercury that is unlike that of any of the other Planets in the Solar System. These giant scarps are believed to have formed when Mercury’s interior cooled and the entire Planet shrank slightly as a result.
However, Mariner 10 was able to view less than half the planet, so the global extent of these scarps has been unknown. MESSENGER images, like this one, are providing the first high-resolution looks at many areas on Mercury's surface, and science team members are busy mapping these newly discovered scarps to see whether they are common everywhere on the planet.
Mission Elapsed Time (MET) of image: 108826206
MareKromium
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![Nome del file=ZP-Mercury-PIA10380.jpg
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Aggiunta il=Ago 24, 2008 ZP-Mercury-PIA10380.jpg](albums/userpics/10060/small_ZP-Mercury-PIA10380.jpg)
ZP-Mercury-PIA10380.jpgMercury's Internal Magnetic Field55 visiteCaption NASA:"This depiction of a simulated Mercury Magnetosphere shows representations of the distortions of the Planetary Magnetic Field Lines (blue) by the Solar Wind. Mariner 10 data showed the first evidence for a Magnetic Field at Mercury, an unexpected result. The equatorial pass of MESSENGER during quiet solar conditions provided better data than were available from Mariner 10.
MESSENGER saw an Internal Magnetic Field that is well described by the field from a dipole nearly aligned with the Planet's Spin Axis (dipole tilt ~ 10°). This geometry is similar to that observed by Mariner 10 during its first flyby. The field strength is weaker by about one third than that detected by Mariner 10 during its third (and last) flyby, owing primarily to the difference in trajectories (Mariner 10 flow directly over the magnetic pole where the field strength is greatest). When corrected for our best estimate for the external field, the MESSENGER observations and the two Mariner 10 passes are consistent with very similar solutions for the mean Planetary Magnetic Dipole. The Dipolar Field is consistent with an active electrical dynamo in which the magnetic field is produced by electrical currents flowing in an outer core of molten metal.
The observations do not yet allow us to identify whether a small secular variation may have occurred, determine higher order structure in the field, or assess whether crustal magnetic signatures may be present at other longitudes.
A combination of the next two flybys and the orbital phase of MESSENGER's mission will be required to sort out all of these possible effects".MareKromium
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![Nome del file=ZZ-Mercury-Limb-208882.jpg
Dimensione del file=198KiB
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Aggiunta il=Gen 21, 2008 ZZ-Mercury-Limb-208882.jpg](albums/userpics/10060/small_ZZ-Mercury-Limb-208882.jpg)
ZZ-Mercury-Limb-208882.jpgMercury's Horizon (HR)53 visiteJust 9 minutes after MESSENGER passed 200 Km (about 124 miles) above the surface of Mercury – its closest distance to the Planet during the January 14, 2008, flyby – the probe’s Wide Angle Camera (WAC) on the Mercury Dual Imaging System (MDIS) snapped this image.
The WAC is equipped with 11 different narrow-band filters, and this image was taken in filter 7, which is sensitive to light near the red end of the visible spectrum (750 nm). This view, also imaged through the remaining 10 WAC filters, is from the first set of images taken following MESSENGER's closest approach with Mercury.
The image shows Mercury's surface as seen from a low viewing angle, looking over the surface and off the limb of the Planet on the right side of the image.
The cratered terrain in the image is on the side of Mercury unseen by spacecraft prior to this MESSENGER flyby.
This scene was imaged at multiple viewing angles as MESSENGER sped away from Mercury, and these multiple views of the same surface features from different perspectives and in different colors will be used to help understand the properties of Mercury's surface.MareKromium
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![Nome del file=ZZ-Mercury-Limb-208698.jpg
Dimensione del file=460KiB
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Aggiunta il=Gen 19, 2008 ZZ-Mercury-Limb-208698.jpg](albums/userpics/10060/small_ZZ-Mercury-Limb-208698.jpg)
ZZ-Mercury-Limb-208698.jpgMercury's Horizon (HR)53 visiteAs NASA’s MESSENGER drew closer to Mercury for its historic first flyby, the Spacecraft acquired this image showing a variety of surface textures, including smooth plains at the center of the image, numerous impact craters and rough material that appears to have been ejected from the large crater to the lower right.
MESSENGER has acquired over 1200 images of Mercury. These types of images will assist scientists to study, as never before, details to help them learn about the history and evolution of the innermost Planet.MareKromium
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![Nome del file=ZP-Mercury-PIA10396.jpg
Dimensione del file=171KiB
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Aggiunta il=Ago 24, 2008 ZP-Mercury-PIA10396.jpg](albums/userpics/10060/small_ZP-Mercury-PIA10396.jpg)
ZP-Mercury-PIA10396.jpgMercury's "Sodium Tail"54 visiteCaption NASA:"This plot shows the intensity of emission of light associated with Sodium (Na) Atoms in the vicinity of Mercury. The observations were made with the Ultraviolet and Visible Spectrometer (UVVS) section of the Mercury Atmospheric and Surface Composition Spectrometer (MASCS). The intensity (up to 40 kiloRayleighs) indicates the relative abundance of material - in this case Sodium Atoms - along the observational line of sight back to the Spacecraft.
While Sodium from Mercury has been observed with Earth-based telescopes, this is the highest-spatial-resolution image ever made.
The geometry and observing circumstances have to be disentangled to infer the true spatial distribution, but the observations do confirm a North-South asymmetry that has previously been observed in ground-based Sodium images.
The Sodium emission is at 589 nm (in the visible part of the spectrum and the same wavelength, or color, as in sodium lamps and street lights on Earth). Because Sodium Atoms have intense emission, they are easy to detect, and this makes sodium a good tracer for other volatile elements in Mercury's Exosphere".MareKromium
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![Nome del file=Mercury - Photo Mosaic - Mariner 10.jpg
Dimensione del file=351KiB
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Aggiunta il=Lug 21, 2004 Mercury - Photo Mosaic - Mariner 10.jpg](albums/userpics/10008/small_Mercury%20-%20Photo%20Mosaic%20-%20Mariner%2010.jpg)
Mercury - Photo Mosaic - Mariner 10.jpgMercury photo-mosaic from Mariner 1064 visiteE non si tratterà, ovviamente, di una passeggiata: sono infatti previste ben tre spinte gravitazionali per la Sonda! La prima verrà data dalla Terra, nell'Agosto 2005; la seconda e la terza, da Venere, rispettivamente, nell'Ottobre 2006 e nel Giugno 2007. Dopodichè, salvo il ricorso a qualche ulteriore e, al momento, non prevedibile micro-correzione di rotta, Messenger arriverà nei pressi di Mercurio ed effettuerà, prima dell'Orbital Insertion, tre Fly-Bys (Passaggi Ravvicinati): Gennaio ed Ottobre 2008 e Settembre 2009.
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![Nome del file=Mercury 1.jpg
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Aggiunta il=Lug 08, 2004 Mercury 1.jpg](albums/userpics/10008/small_Mercury%201.jpg)
Mercury 1.jpgMercury photo-mosaic from Mariner 1055 visite...sarà di gran lunga maggiore (a livello previsionale e sulla base delle stime fatte sulla Terra, sperimentalmente) di quanto non lo sarebbe stata se la parte rocciosa di Mercurio si fosse invece venuta a trovare connessa indissolubilmente ad un nucleo esterno totalmente ghiacciato e solidificato (ossìa con il mantello, il nucleo esterno ed il nucleo interno del Pianeta UNITI a formare un "pezzo unico").
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