| Piú votate - Mariner, Viking & MGS's Maps & Mars in the '70s |
N-Mariner4-66.jpgGlobal Sand&Dust-storm from Mariner 4 (possible thick clouds)55 visitenessun commento
(3 voti)
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ZD-E-Viking1-p7273b~0.jpgThe South-western horizon of Viking 1 (3)87 visiteCaption NASA originale:"This same crater has also been identified in Orbiter photographs and then used to locate the Lander position. Also visible beyond the crater rim is a ridge 8 to 10 Km distant".
(3 voti)
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ZE-I-Viking1-p135b.jpgColor snap-shots from Viking 1 (5)67 visitenessun commento
(3 voti)
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ZE-I-Viking1-p133b.jpgColor snap-shots from Viking 1 (2)80 visite"...Even for pictures where we have both visible and IR information, two possible types of color can be created. The character of the Sunlight reaching the Martian Surface is significantly different than that reaching Earth's surface, primarily because of scattering and absorption by suspended dust particles. In addition, a certain amount of light reflected from the yellowish brown surface finds its way back as reflected sky light.
Figures (1), (2), and (3) illustrate the range of possible color reconstructions. All three pictures are based on the same camera data. The sampling area at the Viking 1 Site is shown. Two trenches in the Sandy Flats site, the first to be dug are shown at the far left.
Figure (1) is produced by using only visible color information, making no allowance for IR leaks..." (continua)
(3 voti)
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QB-VikingOne-PIA08616-02.jpgViking One: the Landing Site, 30 years after the landing... (3)65 visiteCaption NASA originale:"The MOC image of that location, acquired in 2003, showed additional near-field features (rocks associated with a nearby crater) that closely matched the Viking 1 images (frames 2 and 3, where "B" denotes "Volkswagen Rock"). The inset (upper right of frame 3) is an enlargement that shows the location of the Viking 1 Lander.
The MOC image of the Viking 1 Lander Site (3) was acquired during a test of the MGS Pitch and Roll Observation (PROTO) technique conducted on May 11, 2003. (Following initial tests, the "c" part of "cPROTO" was begun by adding compensation for the motion of the Planet to the technique). The PROTO or cPROTO approach allows MOC to obtain images with better than its nominal 1,5 mt (5 ft) per pixel resolution.
The image shown here (3) was map projected at 50 cm (~20") per pixel. The full 11 May 2003 image can be viewed in the MOC Gallery, it is image R05-00966.
In addition to celebrating the 30th anniversary of the first U.S. robotic Mars landing, we note that 20 July is also the 37th anniversary of the first human landing on the Moon, on 20 July 1969. There are two dates that are most sacred in the space business (three, if you count the 4 October 1957 launch of Sputnik 1). The other date is 12 April, which celebrates the 1961 launch of the first human in space, and the 1981 launch of the first space shuttle orbiter".
(3 voti)
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QB-VikingOne-PIA08616-00.jpgViking One: the Landing Site, 30 years after the landing... (1)82 visiteCaption NASA originale:"Viking 1 landed 30 years ago, on July 20, 1976. It was the first U.S. landing on Mars and a very exciting time for Mars Exploration. Since that time, 4 additional Spacecrafts have successfully landed on Mars and conducted their science investigations. Today, new missions to the Martian Surface are in the works, with landings expected in 2008 (Phoenix) and 2010 (Mars Science Laboratory).
The Viking 1 Lander is difficult to see in MGS-MOC images. The Western Chryse Planitia Landing Site is often obscured by dust hazes and occasional storms, especially during Northern Winter, which would otherwise be the best time to look for the Lander from orbit because the Sun casts longer shadows in Winter.
When the atmosphere is clearest, in portions of the Spring and Summer, the Sun is higher in the sky as seen from MGS's orbit. The spacecraft always passes over the Landing Site Region around 2 p.m. in the afternoon".
(3 voti)
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Marsorbitsolarsystem.gifEarth and Mars: the Orbital motion144 visiteUna GIF molto interessante e ben fatta che illustra con chiarezza come mai un Anno Marziano equivale, sostanzialmente, a due Anni Terrestri (in effetti, il Periodo di Rivoluzione di Marte intorno al Sole dura - circa - 687 Giorni Terrestri).MareKromium
(2 voti)
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ZE-I-Viking1-PIA10738.jpgMars Surface near Viking Lander 1 Footpad (MULTISPECTRUM; credits: Lunexit)73 visiteCaption NASA:"This image, which has been flipped horizontally, was taken by Viking Lander 1 on August 1st, 1976, 12 Soles after the landing. Much like images that have returned from Phoenix, the soil beneath Viking 1 has been exposed due to exhaust from thruster engines during descent.
This is visible to the right of the struts of Viking's surface-sampler arm housing, seen on the left".MareKromium
(2 voti)
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O-Mariner9-72-Pollack_Crater_and_White-Rock.jpgPollack Crater and "White Rock" from Mariner 9 (RAW Frame - credits: NASA)54 visite"...It was interesting to browse through the Mariner 9 data set to locate these images, because evidently the Mariner 9 Team wasn't sure to make of these strange bright deposits.
The first one I posted was described as "white rock" in a comment on the image, and that name has stuck. But another image's descriptive comment read "curious ice patches".
Another totally misidentified not only the nature but the location of the photo, describing it as "Polar Cap".
Comments on images of other places in the Mariner 9 Catalog generally reflect the fact that Mars had not yet been systematically surveyed by an orbiter, so the scientists often weren't quite sure what they were looking at, and even when it was clear there were craters, those craters had mostly not yet been named.
I came across comments like "peculiar filametary structure" and "possible craters" and "streaky detail" and "cloud?" and "multitude of surface detail" and "odd fork-shaped bright pattern."
It's fun to browse through that table and imagine surveying Mars, with a spacecraft stationed at the Planet for the first time, made all the more dramatic by its initial obscuration by a dust storm that slowly cleared.
Mariner 9 is one of the more challenging data sets to work with because it's just so old. However, everything you need to access it, find images, view them, and convert them to more familiar formats is readily available online. First of all, the data itself can be found by browsing the data volumes at the PDS Imaging Node, and you can learn a little bit about the data at the National Space Science Data Center. To figure out what's what and to try to track down images of specific areas, you can download this spreadsheet (XLS format, zipped, 7.5 MB) containing an index to all the images.
The images are all in a format that won't be familiar to most of you, but like most spacecraft data you can convert a folder full of images to PNG format using my favorite amateur-produced software, Björn Jónsson's IMG2PNG. However, if you're only working with a couple of images, I'd recommend a different amateur-produced piece of software for converting the images, Piotr Masek's MarinerView, because MarinerView can be used to correct the Mariner 9 images (one at a time) for the little white specks of noise that are spattered across every one.
I'm slowly working on tracking down images of "White Rock" taken by every mission. First Mariner 9, then the Viking orbiters, then Mars Global Surveyor's MOC, then Mars Odyssey THEMIS, then Mars Express HRSC, and, finally, I should be able to produce Mars Reconnaissance Orbiter views from three different instruments: HiRISE, CTX, and CRISM. Stay tuned for further installments...".
Emily Lakdawalla (Planetary Society)MareKromium
(2 voti)
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N-Mariner6-01_enf_08.jpgMars from Mariner 6: approaching Mars54 visitevedasi quanto dedotto in sede di commento al frame precedente
(2 voti)
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N-Mariner6-02_con_05b.jpgMars from Mariner 6: Lava Flows and shallow craters53 visiteNota: il "punto scuro" che si vede circa ad ore 08:00 del frame potrebbe essere l'ombra di Deimos (anche se non siamo in grado di escludere l'ipotesi per cui si possa anche trattare di un image-artifact).
(2 voti)
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N-Mariner6-02_con_07b.jpgMars from Mariner 6: Crater Clusters' Region and Lava Flows53 visitevedasi quanto dedotto in sede di commento al frame precedente
(2 voti)
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