Sincere wishes to move forward...
May the Divine be with u forever..
AurionMission.
http://obamamessiah.blogspot.com/
Wednesday, August 3, 2011
Aloha Mr.Prez Obama
Happy Birthday dear President.
Sincere wishes to move forward...
May the Divine be with u forever..
AurionMission.
Also check
http://obamamessiah.blogspot.com/
Sincere wishes to move forward...
May the Divine be with u forever..
AurionMission.
http://obamamessiah.blogspot.com/
Crash or Coincidence?
An odd-looking impact feature raises an intriguing, Apollo-era trivia question (3.02°N, 119.15°E). NAC image number M141485413; incidence angle 12°; Sun is from the east; north is up; image is ~600 meters across [NASA/GSFC/Arizona State University].
http://lroc.sese.asu.edu/news/index.php?/archives/421-Crash-or-Coincidence.html
What caused this peculiar-looking impact? The "butterfly"-shaped ejecta pattern is diagnostic of a low-angle collision (see another example here). The dark/light contrasting tones are indicative of compositional or maturity differences among the target materials (see another example here). This much we understand. But was it created by a chunk of space debris or from the crash landing of a space probe? The LROC NAC resolution is so high that small features from Apollo-era landed or crashed spacecraft are often visible. Today's Featured Image is a fitting topic for the 42nd anniversary of the Apollo 11 landing, which landed safely in Mare Tranquillitatis on July 20, 1969.
Lunar Orbiter 2 was an unmanned imaging spacecraft used in November and early December 1966 to aid with Apollo and Surveyor landing site selection. The spacecraft became famous in 1967 with the public release of an oblique image of Copernicus crater (one of only four obliques collected), which was hailed as the "Picture of the Century"
by the news media of the day. According to the 2007 International Atlas of Lunar Exploration, the Lunar Orbiter 2 spacecraft was commanded to crash into the lunar farside surface on October 11, 1967. The coordinates of the Lunar Orbiter 2 impact are given as 119.1° east longitude and 3.0° north latitude, which match those of the feature in the NAC image (measured at 119.149° east longitude, and 3.020° north latitude). However, the published Lunar Orbiter 2 numbers are given as a rough estimate because the impact occurred on the farside of the Moon, out of direct radio contact. So the match with the NAC coordinates could be a coincidence. The impact appears much too large (~85 m in diameter) to be the result of an impact from a spacecraft only a few meters tall, but with a solar incidence angle of only 12 degrees, it is difficult to see the crater rim and find out the true diameter. Perhaps the ejecta pattern extends far beyond the immediate impact. The truth is that we are not sure what caused this impact feature. We are currently re-targeting the area under a higher incidence angle to help with crater rim measurements. Stay tuned!
What additional clues would you look for to satisfy this mystery? The feature is very asymmetrical. Would it help to know the orientation of Lunar Orbiter 2's final orbit? Why? Here is a good discussion for the classroom!
See if you can find the tiny feature in the full NAC image here, and look to the following Featured Image posts for additional spacecraft recovered through NAC targeting.
Apollo 11 landing site
Apollo 16 landing site
What caused this peculiar-looking impact? The "butterfly"-shaped ejecta pattern is diagnostic of a low-angle collision (see another example here). The dark/light contrasting tones are indicative of compositional or maturity differences among the target materials (see another example here). This much we understand. But was it created by a chunk of space debris or from the crash landing of a space probe? The LROC NAC resolution is so high that small features from Apollo-era landed or crashed spacecraft are often visible. Today's Featured Image is a fitting topic for the 42nd anniversary of the Apollo 11 landing, which landed safely in Mare Tranquillitatis on July 20, 1969.
Lunar Orbiter 2 was an unmanned imaging spacecraft used in November and early December 1966 to aid with Apollo and Surveyor landing site selection. The spacecraft became famous in 1967 with the public release of an oblique image of Copernicus crater (one of only four obliques collected), which was hailed as the "Picture of the Century"
What additional clues would you look for to satisfy this mystery? The feature is very asymmetrical. Would it help to know the orientation of Lunar Orbiter 2's final orbit? Why? Here is a good discussion for the classroom!
See if you can find the tiny feature in the full NAC image here, and look to the following Featured Image posts for additional spacecraft recovered through NAC targeting.
Apollo 11 landing site
Apollo 16 landing site
Natural Bridge on the Moon!
Natural Bridge on the Moon! |  |
Another amazing bit of lunar geology revealed by LROC! NAC M113168034R, north is up [NASA/GSFC/Arizona State University].
Just when you think you have seen everything, LROC reveals a natural bridge on the Moon! Who would have thought? Natural bridges on the Earth are typically the result of wind and water erosion - not a likely scenario on the Moon. So how did this natural bridge form? The most likely answer is dual collapse into a lava tube. From the Apollo era, SELENE, and LROC images, we know that lava tubes did form in the Moon's ancient past. SELENE and LROC images have raised the tantalizing prospects that lava tubes remain intact to this day. However this bridge did not form in mare (basalt), but rather in impact melt from King crater! More astonishingly, the same NAC image revealed two natural bridges - not just one!
The bridge is approximately 7 meters wide on top and perhaps 9 meters on the bottom side, and is a 20 meter walk for an astronaut to cross from one side to the other [NASA/GSFC/Arizona State University].
How do we know for sure that this feature is truly a bridge? Look closely at the west pit (left side) and you can see a little crescent of light on its floor. That patch of light came from the east, under the bridge. In another lower resolution image (see inset), you can see light passed under the bridge from the west. So there must be a passage. How did this oddity form? The impact melt deposit on the north rim of King crater is over 15 km across and was emplaced in a matter of minutes as the crater grew to its final configuration.
A large (17 km east to west), smooth impact melt "pond" on the northwest rim of King crater (72 km diameter). LROC WAC mosaic [NASA/GSFC/Arizona State University].
The impact melt that was thrown out of the crater pooled on the newly deposited ejecta and must be many tens of meters thick, allowing its interior to stay molten for a long time. As the local terrain readjusted after the shock of the impact, the substrate of this massive pool of melt was jostled to some degree. Local pressures built up and the melt moved around under a deforming crust. You can see that the south end of the bridge extends from a small local rise, shaped something like a blister. Perhaps some melt was locally pushed up forming the rise, then the magma found a path to flow away, leaving a void which the crusted roof partially collapsed? Right now we do not know for certain the details of how the bridge formed, however, the LROC team is processing stereo images into topographic maps to aid scientists in determining exactly what took place on this fascinating melt sheet. There are actually six NAC images in which you can find the bridge under varying lighting (M103725084L, M103732241L, M106088433L, M113168034R, M123785162L, M123791947L). Why so many images? The melt sheet north of King crater is one of the Constellation regions of interest - a high priority for LROC coverage. As the pair of images below vividly illustrate, having a set of images of the same under varying lighting allows scientists to more confidently interpret the local geology and thus better prepare for future exploration.
Left shows the bridge when the Sun is 42° above the horizon and the right is the same area when the Sun is 80° above the horizon (near noon). M113168034R on the left, M123791947L on the right, both are 128 meters across, north is up [NASA/GSFC/Arizona State University].
Explore the entire LROC NAC image and investigate the variety of geologic features in the King crater melt sheet. Can you find the second natural bridge in the full NAC frame (hint - it's fairly close to the one shown above and about half its size)?
Learn more about the Constellation regions of interest:
Tier1 Regions
Tier2 Regions
Asteriod Vesta by Dawn spacecraft
Dawn, as a mission belonging to NASA’s Discovery Program, delves into the unknown, drives new technology innovations, and achieves what's never been attempted before. In Dawn’s case, it is orbiting one member of the main asteroid belt, Vesta, before heading to gather yet more data at a second, Ceres.
Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail two of the largest protoplanets remaining intact since their formations. Ceres and Vesta reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Each has followed a very different evolutionary path constrained by the diversity of processes that operated during the first few million years of solar system evolution.
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