Archive for Shackleton Crater

Walls of lunar crater may hold patchy ice

By alkaon on September 5, 2012 No Comments

Scientists using the Mini-RF radar on NASA’s Lunar Reconnaissance Orbiter (LRO) have estimated the maximum amount of ice likely to be found inside a permanently shadowed lunar crater located near the Moon’s south pole. As much as 5 to 10 percent of material, by weight, could be patchy ice, according to the team of researchers led by Bradley Thomson at Boston University’s Center for Remote Sensing.

“These terrific results from the Mini-RF team contribute to the evolving story of water on the Moon,” says LRO’s deputy project scientist, John Keller of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Several of the instruments on LRO have made unique contributions to this story, but only the radar penetrates beneath the surface to look for signatures of blocky ice deposits.”

These are the first orbital radar measurements of Shackleton Crater, a high-priority target for future exploration. The observations indicate an enhanced radar polarization signature, which is consistent with the presence of small amounts of ice in the rough inner wall slopes of the crater.

“The interior of this crater lies in permanent shadow and is a ‘cold trap’ — a place cold enough to permit ice to accumulate,” says Mini-RF principal investigator Ben Bussey of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “The radar results are consistent with the interior of Shackleton containing a few percent ice mixed into the dry lunar soil.”

These findings support the long-recognized possibility that areas of permanent shadow inside polar impact craters are sites of the potential accumulation of water. Numerous lines of evidence from recent spacecraft observations have revised the view that the lunar surface is a completely dry, inhospitable landscape. Thin films of water and hydroxyl have been detected across the lunar surface using several space-borne near-infrared spectrometers. Additionally, orbital neutron measurements indicate elevated levels of near‐surface hydrogen in the polar regions; if in the form of water, this hydrogen would represent an average ice concentration of about 1.5 percent by weight in the polar regions.

The Shackleton findings also are consistent with those of the recent LCROSS spacecraft’s controlled collision with a nearby permanently shadowed polar region near the lunar south pole, which revealed evidence for water in the plume kicked up by its impact. A radar instrument flown on India’s Chandrayaan-1 spacecraft in 2009 found evidence for ice deposits in craters at the lunar north pole. Measurements of the albedo (surface reflectance) inside Shackleton Crater using LRO’s laser altimeter and far‐ultraviolet detector are also consistent with the presence of a small amount of ice.

“Inside the crater, we don’t see evidence for glaciers like on Earth,” says Thomson. “Glacial ice has a whopping radar signal, and these measurements reveal a much weaker signal consistent with rugged terrain and limited ice.”

The radar measurements of Shackleton Crater were made during three separate observations between December 2009 and June 2010. Radar illuminates shadowed regions and can detect deposits of water or ice, which have a distinctive radar polarization signature compared to the surrounding material. In addition, radar penetrates the terrain to depths of a meter or two and can measure water or ice buried beneath the surface. Radar measurements of Shackleton Crater place an upper bound on the ice content of the uppermost meter of loose material of the crater’s walls at between 5 and 10 percent ice by weight.

“We are following up these tantalizing results with additional observations,” says Bussey. “Mini-RF is currently acquiring new bistatic radar images of the Moon using a signal transmitted by the Arecibo radio telescope in Puerto Rico. These bistatic images will help us distinguish between surface roughness and ice, providing further unique insights into the locations of volatile deposits.”

Article source: http://www.astronomy.com/~/link.aspx?_id=dfe6efab-b08e-4b0b-b2ff-4092bcfba294

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Moon crater may hold vast quantities of ice, says NASA

By alkaon on June 23, 2012 No Comments

Officials at NASA say that a crater on the moon hold vast quantities of water in the form of ice, a discovery that could pave the way for future mission to the Earth satellite.

New research shows there may be frozen water inside a massive crater, called the Shackleton crater, say NASA scientists. Researchers from NASA, MIT, and Brown University say they studied the crater with the help of a laser device, and they note that recorded measurements indicate the presence of ice. The team of astronomers say the laser lit up the area and allowed them to measure the natural reflectivity inside the crater.

“While the distribution of brightness was not exactly what we had expected, practically every measurement related to ice and other volatile compounds on the moon is surprising, given the cosmically cold temperatures inside its polar craters,” said the scientists.

Using NASA’s Lunar Reconnaissance Orbiter, the team of astronomers essentially illuminated the crater’s interior with infrared laser light, measuring how reflective it was. In a statement released Thursday, the team noted that the latest data shows that upwards of 20 percent of the crater could be covered in ice. That said, the measured reflectance could be the result of something else entirely, including mineral deposits located on the floor of the crater.

“The reflectance could be indicative of something else in addition to or other than water ice,” said study lead author Maria Zuber, a geophysicist at the Massachusetts Institute of Technology. For instance, the crater floor might be reflective because it could have had relatively little exposure to solar and cosmic radiation that would have darkened it.

Ms. Zuber noted that the measurements only look at a micron-thick portion of Shackleton Crater’s uppermost layer, noting that water may be present at greater depths.

“A bigger question is how much water might be buried at depth,” said Ms. Zuber, adding that NASA’s GRAIL mission will investigate that possibility.

While the crater could hold ice, it remains unclear whether ice actually exists at the bottom of the crater. Researchers say the measurements showed this crater’s floor is much brighter than the floor of other nearby craters, suggesting there may be ice in it, but they added that they can’t be sure.

Scientists estimate there could be as much as 100 gallons of ice inside the two-mile deep crater.

Shackleton crater is very large at 2 miles deep and more than 12 miles wide. Astronomers have studied the crater in recent years, searching for ice deposits in the interior of the crater, which is permanently dark. While scientists have long posited that ice may exist on the moon, previous orbital and Earth-based observations of lunar craters have yielded conflicting interpretations over whether ice is actually there.

The data comes just months after NASA celebrated the 2012 New Year earlier this year by completing a space administration first, announcing two probes in lunar orbit. For NASA, the announcement was a fulfillment of the space agency’s New Year’s wish. NASA will use GRAIL-A and GRAIL-B to study Earth’s closest neighbor, the moon.

According to the space administration, the GRAIL mission will be “the first time any space agency has attempted the complex set of maneuvers required to place two robotic spacecraft into the same precise orbit around a planetary body other than Earth so they can fly in formation.”

The probes will spend about two months reshaping and merging their orbits until one spacecraft is following the other in the same low-altitude, near-circular, near-polar orbit, and they begin formation-flying. The next 82 days will constitute the science phase, during which the spacecraft will map the Moon’s gravitational field.

Article source: http://www.thebunsenburner.com/news/moon-crater-may-hold-vast-quantities-of-ice-says-nasa/

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Moon crater may hold tons of ice, says NASA

By alkaon on June 23, 2012 No Comments

Officials at NASA say that a crater on the moon hold vast quantities of water in the form of ice, a discovery that could pave the way for future mission to the Earth satellite.

New research shows there may be frozen water inside a massive crater, called the Shackleton crater, say NASA scientists. Researchers from NASA, MIT, and Brown University say they studied the crater with the help of a laser device, and they note that recorded measurements indicate the presence of ice. The team of astronomers say the laser lit up the area and allowed them to measure the natural reflectivity inside the crater.

“While the distribution of brightness was not exactly what we had expected, practically every measurement related to ice and other volatile compounds on the moon is surprising, given the cosmically cold temperatures inside its polar craters,” said the scientists.

Using NASA’s Lunar Reconnaissance Orbiter, the team of astronomers essentially illuminated the crater’s interior with infrared laser light, measuring how reflective it was. In a statement released Thursday, the team noted that the latest data shows that upwards of 20 percent of the crater could be covered in ice. That said, the measured reflectance could be the result of something else entirely, including mineral deposits located on the floor of the crater.

“The reflectance could be indicative of something else in addition to or other than water ice,” said study lead author Maria Zuber, a geophysicist at the Massachusetts Institute of Technology. For instance, the crater floor might be reflective because it could have had relatively little exposure to solar and cosmic radiation that would have darkened it.

Ms. Zuber noted that the measurements only look at a micron-thick portion of Shackleton Crater’s uppermost layer, noting that water may be present at greater depths.

“A bigger question is how much water might be buried at depth,” said Ms. Zuber, adding that NASA’s GRAIL mission will investigate that possibility.

While the crater could hold ice, it remains unclear whether ice actually exists at the bottom of the crater. Researchers say the measurements showed this crater’s floor is much brighter than the floor of other nearby craters, suggesting there may be ice in it, but they added that they can’t be sure.

Scientists estimate there could be as much as 100 gallons of ice inside the two-mile deep crater.

Shackleton crater is very large at 2 miles deep and more than 12 miles wide. Astronomers have studied the crater in recent years, searching for ice deposits in the interior of the crater, which is permanently dark. While scientists have long posited that ice may exist on the moon, previous orbital and Earth-based observations of lunar craters have yielded conflicting interpretations over whether ice is actually there.

The data comes just months after NASA celebrated the 2012 New Year earlier this year by completing a space administration first, announcing two probes in lunar orbit. For NASA, the announcement was a fulfillment of the space agency’s New Year’s wish. NASA will use GRAIL-A and GRAIL-B to study Earth’s closest neighbor, the moon.

According to the space administration, the GRAIL mission will be “the first time any space agency has attempted the complex set of maneuvers required to place two robotic spacecraft into the same precise orbit around a planetary body other than Earth so they can fly in formation.”

The probes will spend about two months reshaping and merging their orbits until one spacecraft is following the other in the same low-altitude, near-circular, near-polar orbit, and they begin formation-flying. The next 82 days will constitute the science phase, during which the spacecraft will map the Moon’s gravitational field.

Article source: http://www.thebunsenburner.com/news/moon-crater-may-hold-tons-of-ice-says-nasa/

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Researchers estimate ice content of crater at Moon’s south pole

By alkaon on June 22, 2012 No Comments

NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft has returned data that indicate ice may make up as much as 22 percent of the surface material in a crater located on the Moon’s south pole.

A team of NASA and university scientists using laser light from LRO’s laser altimeter examined the floor of Shackleton Crater. They found that the crater’s floor is brighter than those of other nearby craters, which is consistent with the presence of small amounts of ice. This information will help researchers understand crater formation and study other uncharted areas of the Moon.

“The brightness measurements have been puzzling us since two summers ago,” said Gregory Neumann of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “While the distribution of brightness was not exactly what we had expected, practically every measurement related to ice and other volatile compounds on the Moon is surprising, given the cosmically cold temperatures inside its polar craters.”

The spacecraft mapped Shackleton Crater with unprecedented detail, using a laser to illuminate the crater’s interior and measure its albedo, or natural reflectance. The laser light measures to a depth comparable to its wavelength, or about a micron. That represents a millionth of a meter, or less than one ten-thousandth of an inch. The team also used the instrument to map the relief of the crater’s terrain based on the time it took for laser light to bounce back from the Moon’s surface. The longer it took, the lower the terrain’s elevation.

In addition to the possible evidence of ice, the group’s map of Shackleton revealed a remarkably preserved crater that has remained relatively unscathed since its formation more than 3 billion years ago. The crater’s floor is itself pocked with several small craters, which may have formed as part of the collision that created Shackleton.

The crater, named after the Antarctic explorer Ernest Shackleton, is 2 miles (3 kilometers) deep and more than 12 miles (19 kilometers) wide. Like several craters at the Moon’s south pole, the small tilt of the lunar spin axis means Shackleton Crater’s interior is permanently dark, and therefore extremely cold.

“The crater’s interior is extremely rugged,” said Maria Zuber from the Massachusetts Institute of Technology in Cambridge. “It would not be easy to crawl around in there.”

While the crater’s floor was relatively bright, Zuber and her colleagues observed that its walls were even brighter. The finding was at first puzzling. Scientists had thought that if ice were anywhere in a crater, it would be on the floor where no direct sunlight penetrates. The upper walls of Shackleton Crater are occasionally illuminated, which could evaporate any ice that accumulates. A theory offered by the team to explain the puzzle is that “moonquakes”— seismic shaking brought on by meteorite impacts or gravitational tides from Earth — may have caused Shackleton’s walls to slough off older darker soil, revealing newer, brighter soil underneath. Zuber’s team’s ultra-high-resolution map provides strong evidence for ice on both the crater’s floor and walls.

“There may be multiple explanations for the observed brightness throughout the crater,” said Zuber. “For example, newer material may be exposed along its walls, while ice may be mixed in with its floor.”

This visualization, created using Lunar
Reconnaissance Orbiter laser altimeter data, offers a view of Shackleton
Crater located in the south pole of the Moon. Thanks to these
measurements, we now have our best-yet maps of the crater’s
permanently-shadowed interior! Note: This video contains no audio.
Credit: NASA/Goddard/Ernie Wright

Article source: http://www.astronomy.com/~/link.aspx?_id=8bf5b34d-00f1-4cb3-86c8-fe51f47a5e8f

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NASA Spacecraft Reveals Ice Content in Moon Crater

By alkaon on June 21, 2012 No Comments

WASHINGTON, June 20, 2012 — /PRNewswire-USNewswire/ – NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft has returned data that indicate ice may make up as much as 22 percent of the surface material in a crater located on the moon’s south pole.

(Logo: http://photos.prnewswire.com/prnh/20081007/38461LOGO)

The team of NASA and university scientists using laser light from LRO’s laser altimeter examined the floor of Shackleton crater. They found the crater’s floor is brighter than those of other nearby craters, which is consistent with the presence of small amounts of ice. This information will help researchers understand crater formation and study other uncharted areas of the moon. The findings are published in Thursday’s edition of the journal Nature.

“The brightness measurements have been puzzling us since two summers ago,” said Gregory Neumann of NASA’s Goddard Space Flight Center in Greenbelt, Md., a co-author on the paper. “While the distribution of brightness was not exactly what we had expected, practically every measurement related to ice and other volatile compounds on the moon is surprising, given the cosmically cold temperatures inside its polar craters.”

The spacecraft mapped Shackleton crater with unprecedented detail, using a laser to illuminate the crater’s interior and measure its albedo or natural reflectance. The laser light measures to a depth comparable to its wavelength, or about a micron. That represents a millionth of a meter, or less than one ten-thousandth of an inch. The team also used the instrument to map the relief of the crater’s terrain based on the time it took for laser light to bounce back from the moon’s surface. The longer it took, the lower the terrain’s elevation.

In addition to the possible evidence of ice, the group’s map of Shackleton revealed a remarkably preserved crater that has remained relatively unscathed since its formation more than three billion years ago. The crater’s floor is itself pocked with several small craters, which may have formed as part of the collision that created Shackleton.

The crater, named after the Antarctic explorer Ernest Shackleton, is two miles deep and more than 12 miles wide. Like several craters at the moon’s south pole, the small tilt of the lunar spin axis means Shackleton crater’s interior is permanently dark and therefore extremely cold.

“The crater’s interior is extremely rugged,” said Maria Zuber, the team’s lead investigator from the Massachusetts Institute of Technology in Cambridge in Mass. “It would not be easy to crawl around in there.”

While the crater’s floor was relatively bright, Zuber and her colleagues observed that its walls were even brighter. The finding was at first puzzling. Scientists had thought that if ice were anywhere in a crater, it would be on the floor, where no direct sunlight penetrates. The upper walls of Shackleton crater are occasionally illuminated, which could evaporate any ice that accumulates. A theory offered by the team to explain the puzzle is that “moonquakes”– seismic shaking brought on by meteorite impacts or gravitational tides from Earth — may have caused Shackleton’s walls to slough off older, darker soil, revealing newer, brighter soil underneath. Zuber’s team’s ultra-high-resolution map provides strong evidence for ice on both the crater’s floor and walls.

“There may be multiple explanations for the observed brightness throughout the crater,” said Zuber. “For example, newer material may be exposed along its walls, while ice may be mixed in with its floor.”

The initial primary objective of LRO was to conduct investigations that prepare for future lunar exploration. Launched in June 2009, LRO completed its primary exploration mission and is now in its primary science mission. LRO was built and is managed by Goddard. This research was supported by NASA’s Human Exploration and Operations Mission Directorate and Science Mission Directorate at the agency’s headquarters in Washington.

For an image of the crater, visit:

http://go.nasa.gov/MlzloW

For more information about NASA’s Lunar Reconnaissance Orbiter mission, visit:

http://www.nasa.gov/lro

SOURCE NASA

Article source: http://www.sacbee.com/2012/06/20/4576608/nasa-spacecraft-reveals-ice-content.html

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Huge Moon Crater’s Water Ice Supply Revealed

By alkaon on June 21, 2012 No Comments

Shackleton Crater, a potential base for human exploration, may really have water ice on its floor.

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NASA Image of the day

The Engine Burns Blue

 
This image shows a cutting-edge solar-electric propulsion thruster in development at NASA's Jet Propulsion Laboratory, Pasadena, Calif., that uses xenon ions for propulsion. An earlier version of this solar-electric propulsion engine has been flying on NASA's Dawn mission to the asteroid belt. This engine is being considered as part of the Asteroid Initiative, a proposal to robotically capture a small near-Earth asteroid and redirect it safely to a stable orbit in the Earth-moon system where astronauts can visit and explore it. This image was taken through a porthole in a vacuum chamber at JPL where the ion engine is being tested. Image credit: NASA/JPL-Caltech
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