Space and astronomy news
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Happy Valentines Day from everyone here at Universe Today, and the Moon, too. In 3-D, no less.
Thanks to Nathanial Burton-Bradford for sending us this image. He found it while searching through the Lunar Reconnaissance Orbiter Camera’s data set. Check out Nathanial’s Flickr page for larger versions of this one, and more. See the image below in its proper orientation for viewing in 3-D:
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Follow-up observations of a potential ‘skylight’ in a lava tube on the Moon has revealed a cavernous lunar pit in the Marius Hills region, with a view of the interior and bottom of the pit. The sun angle, camera angle and lighting conditions were just right for the Lunar Reconnaissance Orbiter camera to look all the way down to the floor of the pit. And this is no small hole in the ground — the LRO team says this pit is about 65 meters in diameter! This latest image confirms this object is actually a subsurface cave; a lava tube close to the surface where part of it has collapsed. These lava tubes could be great locations for lunar bases that could protect human explorers from dangers such as cosmic rays, meteorite impacts, and the extreme temperature differences between the lunar day and night.
This is the fourth time that this particular lunar pit has been imaged. Since LRO is constantly orbiting the Moon and it completes a full cycle of lunar imaging each month, the team can do follow up observations of previous discoveries and re-image targets under different lighting conditions.
Previous images had revealed the dark, cave-like entrance, and another showed part of the pit wall.
For this fourth imaging run, the spacecraft slewed 43° to the east and the solar incidence angle was 34° from vertical. This was just the right angle so that if there actually was an open lava tube extending horizontally its floor would be illuminated.
The LROC team hit paydirt (or pay-regolith, if you will).
With LRO’s Narrow Angle Camera, the team was able to image a few meters under the overhang to show the interior of this sublunarean void. With this oblique angle, they were also able to capture the layered nature of the mare bedrock in the pit walls. These exposed layers give scientists important clues as to how the vast mare were deposited.
The collection of images now verifies this is actually a cavernous subsurface cave. These pits had been predicted to exist, based on the understanding of the geomorphology of mare deposits and lava flow behavior on Earth, but never directly imaged before.
The LROC team will be presenting their findings about this pit and others that have been imaged at the Lunar and Planetary Science Conference. You can read their abstract here. (pdf file).
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40 years ago this week, the Apollo 14 crew landed on the Moon. Here’s the latest look at their landing site, just downloaded from the Lunar Reconnaissance Orbiter’s Narrow Angle Cameras. Even though LRO has imaged this area before, this seems to be a much better, crisper view of the lander and the ALSEP experiment package left of the Moon by Al Shepard and Edgar Mitchell. Also visible are the tracks left where the astronauts walked repeatedly in a “high traffic zone” and perhaps by the Modularized Equipment Transporter (MET) wheelbarrow-like carrier used on Apollo 14. Below are a couple of close-up looks at the image.
The LROC folks say that every time LRO passes overhead the different landing sites, the Sun is at a different position so each image gives a different perspective. Additionally, since the position of the lunar modules and other pieces of hardware are very accurately known, the LROC team can check the accuracy of the mission-provided ephemeris.
Thanks to UT reader Carlos Ayala who sent in this this sharpened and enhanced “closer” close-up. He captured the original image on the LRO site, and “using CS3 I enlarged the area and applied a Bicubic smoothing filter to the re-sampled image. The resulting image is set to 1200 x 1200 pixels,” he wrote us. Click on the image for a larger version.
You can compare the old images with this new one.
Source: LROC
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Shortly after the loss of the Space Shuttle Challenger in 1986, seven craters on the eastern rim of the Apollo basin were named after the crew: Gregory Jarvis, Christa McAuliffe, Ronald McNair, Ellison Onizuka, Judith Resnik, Dick Scobee, Michael Smith. The Lunar Reconnaissance Orbiter Wide Angle Camera recently took this image of the region. Below is a video from the Kaguya spacecraft flying over the area.
According to OnOrbit, the crater “Onizuka” is incorrectly identified in this video. Rather, “Onizuka” is the crater next and to the right of the one labeled in the video as “The Onizuka”.
The Apollo Basin is not where I would have guessed — the area around the Moon’s equator on the near side where all the Apollo landings took place — but instead is a 524 km-diameter impact basin located within the center of the the giant South Pole-Aitken basin, (36°S, 209°E).
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How often have you heard (or thought) the sentiment that all NASA really needs is a President who will issue a bold challenge for the space agency, like Kennedy did in 1961, initiating the Apollo program to the Moon? Can we ever expect to witness such a call to action again?
“It is very unlikely,” said space historian and author Andrew Chaikin, who believes Apollo was an historical anomaly. “I think for many decades people saw Apollo as a model for how to do a space program; that you get a President to get up and make a challenge and the country follows along and does great things. But that was only true that one time in the context of the Cold War.”
We went to the Moon when we did not because we were a nation devoted to exploration, Chaikin believes, but because it seemed a politically important course of action in the context of our Cold War with the Soviet Union. “Once that was accomplished, then that political imperative evaporated,” he said.
Likely, we won’t hear any bold space-related challenge in tonight’s State of the Union Address by President Obama. Given the state of the economy, NASA might be facing a cut or freeze on their budget, a fact which might emphasize how unique an event the Apollo program ended up to be.
“What is required now is the development of technologies that will allow us to explore space in a sustainable way,” said Chaikin, author of “A Man on the Moon: The Voyages of the Apollo Astronauts,” who I interviewed for the NASA Lunar Science Institute podcast, “a way that won’t break the bank and will allow us to do more and more with reliable transportation systems that get us up into low Earth orbit. Then perhaps we can build the machines that can actually be stored in space to allow us to venture beyond low Earth orbit to the Moon and even further, to Mars and other destinations in the solar system.”
Chaikin said he’s actually very excited about the work being done in the private sector, such as by SpaceX, one of several commercial space companies trying to develop new transportation systems to provide sustainable hardware and sustainable architecture. “That can allow us to really get back in the game of exploring, not only with robots as we have been doing all along, but with humans again,” Chaikin said.
But Apollo’s uniqueness doesn’t mean it wasn’t important, or hasn’t left a lasting legacy for human spaceflight, and the human race in general.
“Simply put Apollo was the opening act in a story that has no end,” Chaikin said. “It’s a story of human beings leaving their home planet and venturing out into the universe, and as far as we go into space in some distant epoch, when we are living in other star systems and venturing throughout the galaxy, Apollo will have been the first step, so it is absolutely monumental when you look at it in that scale. I think Apollo is a lasting inspiration about what humans can accomplish when they work together.”
Apollo also showed people that anything was possible. “There was a phrase that went into our language after Apollo, and that was ‘If we can put a man on the Moon, why can’t we…’ fill in the blank,” said Chaikin. “The spirit that humans can overcome monumental challenges by working together, I think, is a valid legacy of Apollo culturally.”
Chaikin said Apollo was also important because of the technology development it spurred.
“A lot of the challenges that Apollo presented forced the industries to accelerate their development,” he said, “particularly in microelectronics. It is not that NASA invented all of the microelectronics that we use today but rather that the requirements of building a moon-ship and cramming it with all of the electronics that it needed to do its job required the electronics industry to miniaturize at a faster pace, it required the development of computers that could fit on a spacecraft, it required all kinds of analytical techniques and real-time tracking of the spacecraft as it went to and from the Moon. The legacy today is all the communications technologies and information processing technology that we are surrounded by. That really got an amazing jump start as part of the Apollo program.”
And Apollo also affected our culture, in unique ways we observe even today. How often have you seen the “Earthrise” image taken by Apollo 8 or the picture of Buzz Aldrin standing on the Moon or other Apollo-related imagery in non-space-related venues?
“We got to a place where humans had never been before,” Chaikin said, “and the other lasting legacy is the view that we got from that ‘mountaintop,’ of our Earth as a very precious oasis of life in space, and a world that really is to be cherished and protected.”
We knew even as it was happening, Chaikin said, that seeing our world floating alone in space was perhaps the most profound impact of the voyage.
“In fact, if you look at the front page of the New York Times the very day after Frank Borman and his crew became the first humans to orbit the Moon,” Chaikin said, “you will see an essay by a poet named Archibald MacLeish talking about the impact of that view and the perspective of us as ‘brothers in the eternal cold riding on spaceship Earth.’ So this is one of the things sets Apollo apart from other earlier explorations is that we were experiencing it as it happened through live television and we were actually absorbing and processing the impact in real time.”
But then, humans being as attention-challenged as we are, it didn’t take very long for all of it to become old hat and to kind of recede into history. “And that is where we are today,” Chaikin said.
That being said, Chaikin does not see the Moon as a “been there, done that” world.
“As you know, we’ve been finding frozen water at the poles of the Moon and this is a completely different view of the Moon than we had 40 years ago,” Chaikin said. “And there are more and more intricacies that we are finding all the time. The Moon itself is a Rosetta Stone for deciphering the history of the solar system, and is profoundly valuable world for us on so many levels. And it is a spectacular place. The Apollo astronauts – I’ve spent hours talking to all of them about the Moon, about the experience of being on the Moon and they just say it is a spectacular place.”
“It is too bad that the political impetus for going to the Moon was so short-lived because it was part of the Cold war,” Chaikin continued, “and looking back we can see why that was the case. It is too bad we lost interest in the Moon and it has taken us so long to turn our attention back to the Moon and all it has to offer.”
Listen to the entire interview with Chaikin on the NLSI podcast, which can also be heard on the 365 Days of Astronomy podcast.
For more information about Andrew Chaikin, see his website, andrewchaikin.com
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When people look out of the corner of their eyes, they often don’t see things very clearly. But that’s not the case for the Lunar Reconnaissance Orbiter’s cameras. Occasionally LRO’s cameras are commanded to look off to the side at extreme angles, and the results, thought not frequent, are incredible. This stunning image of the central uplifts inside of Aitken Crater was taken on January 11, 2011. Here, LROC was looking over the southwest ridge of its central peak, and in the distance the lower portion of the northeastern walls of Aitken crater itself is just visible. To quote the Fred Haise character in the movie Apollo 13, this image makes me tempted to take a spacecraft down and “do some prospecting.” …
Mostly, LRO looks straight down for its images, but has collected a limited number of these oblique views of the lunar surface. They are very useful for engineering purposes, but also provide a unique view for visualizing key geologic features on the lunar surface — like Aitken. And usually, they are beautiful shots.
Aitken Crater(~135 km in diameter) is of interest because it is is one of the most geologically diverse settings on the farside. The floor of the crater is covered in mare basalt, which are quite rare on the lunar farside, and lunar scientists are still trying to figure out why. Aitken is also on the northern rim of the great South Pole-Aitken basin, the oldest and largest impact basin on the Moon and one of the oldest and largest impact basins in the whole Solar System! Further exploration of the South Pole-Aitken basin is one of the highest priorities for planetary science in the next decade.
Check out more images from this view of Aitken Crater at the LROC website, where you can “Zoomify” and take a closer look.
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A new study reveals that the water within the Apollo Moon rocks – and within the Moon itself — likely came from comets bombarding the nascent lunar surface, shortly after it formed following an impact event with a young Earth and Mars-sized protoplanet. The recent findings of abundant water at the lunar poles by the LCROSS impactor and across the Moon’s surface by various spacecraft have turned the long-standing notion of a dry Moon on its head, and the past year and a half, researchers have been trying to determine where this unexpected water came from.
“The water we are looking at is internal,” said Larry Taylor from the University of Tennessee, Knoxville, a member of an international team. “It was put into the moon during its initial formation, where it existed like a melting pot in space, where cometary materials were added in at small yet significant amounts.”
Using secondary ion mass spectrometry, the researchers measured the water signatures within rocks returned from the Apollo 11, 12, 14, and 17 missions that landed on the moon between 1969 and 1972. They found the chemical properties of the lunar water were very similar to signatures seen in three different comets: Hyakutake, Hale-Bopp and Halley.
The team found significant water in the lunar mineral apatite from both mare and highlands rocks, which indicates “a role for water during all phases of the Moon’s magmatic history,” the team wrote in their paper. “Variations of hydrogen isotope ratios in apatite suggest sources for water in lunar rocks could come from the lunar mantle, solar wind protons and comets. We conclude that a significant delivery of cometary water to the Earth–Moon system occurred shortly after the Moon-forming impact.”
Even though comet impacts may also have created the Earth’s oceans, Taylor said the water signatures from the mass spectrometer show that the water on the Earth and Moon are different, as apatite has a ratio of the deuterium and hydrogen that are distinctive from those in normal Earth water.
“The values of deuterium/hydrogen (D/H) that we measure in apatite in the Apollo rock samples is clearly distinguishable from water from the Earth, mitigating against this being some sort of contamination on Earth,” said James Greenwood of Wesleyan University, who led the research team.
Initially after the Apollo program, the Moon was believed to extremely dry. Many of the rocks returned by the astronauts and also the Soviet Luna program contained trace water or minor hydrous minerals, but those signatures were attributed to terrestrial contamination since most of the boxes of the Apollo program used to bring the Moon rocks to Earth leaked. This led the scientists to assume that the trace amounts of water they found came from Earth air that had entered the containers. The assumption remained that, outside of possible ice at the moon’s poles, there was no water on the moon.
Forty years later, a trio of spacecraft found evidence of water across the surface of the Moon: The Chandrayaan-1 spacecraft’s Moon Mineralogy Mapper (M Cubed) found that infrared light was being absorbed near the lunar poles at wavelengths consistent with hydroxyl- and water-bearing materials. A spectrometer on the re-purposed Deep Impact probe showed strong evidence that water is ubiquitous over the surface of the moon, and archival data from a Cassini Moon flyby also agreed with the finding that water appears to be widespread across the lunar surface.
“This discovery forces us to go back to square one on the whole formation of the Earth and moon,” said Taylor. “Before our research, we thought the Earth and moon had the same volatiles after the Giant Impact, just at greatly different quantities. Our work brings to light another component in the formation that we had not anticipated — comets.”
Taylor added that the existence of hydrogen and oxygen – water – on the moon can literally serve as a launch pad for further space exploration.
“This water could allow the moon to be a gas station in the sky,” said Taylor. “Spaceships use up to 85 percent of their fuel getting away from Earth’s gravity. This means the moon can act as a stepping stone to other planets. Missions can fuel up at the moon, with liquid hydrogen and liquid oxygen from the water, as they head into deeper space, to other places such as Mars.”
Their paper, “Extraterrestrial Hydrogen Isotope Composition of Water in Lunar Rocks” was published in the journal, Nature Geoscience.
Sources: Nature Geoscience, EurekAlert
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A new look at data from seismic experiments left on the Moon by Apollo astronauts has given researchers a better understanding of the lunar interior. The Moon’s core appears to be very similar to the Earth’s — with a solid inner core and molten liquid outer core — and its size is right in the middle of previous estimates.
“While the presence of a liquid core had previously been inferred from other geophysical measurements, we have made the first direct seismic observation of a liquid outer core,” said Dr. Renee Weber, a planetary scientist at NASA’s Marshall Space Flight Center, who led the team of researchers.
The Apollo Passive Seismic Experiment measured seismic waves on the Moon and consisted of four seismometers deployed on the lunar near side during the Apollo missions between 1969 and 1972. The instruments continuously recorded ground motion until late-1977. But the data was thought to be rather weak because of the small number of stations, the lack of observation of far-side events, and interference from “moon quakes.” As this was the only direct measurements from the Moon available, various researchers differed on key characteristics such as the core’s radius, composition, and state (i.e., whether it was solid or molten.)
“The moon’s deepest interior, especially whether or not it has a core, has been a blind spot for seismologists,” said Ed Garnero, a professor at Arizona State University and a member of the research team. “The seismic data from the old Apollo missions were too noisy to image the moon with any confidence.”
Weber and her colleagues re-analyzed the Apollo data using a method usually used for processing seismic data on Earth. Called array processing, seismic recordings are added together or “stacked” in a special way and studied together. The multiple recordings processed together allow researchers to extract very faint signals. The depth of layers that reflect seismic energy can be identified, ultimately signifying the composition and state of matter at varying depths.
This method can enhance faint, hard-to-detect seismic signals by adding seismograms together.
“If seismic wave energy goes down and bounces off of some deep interface at a particular depth, like the Moon’s core-mantle boundary, then that signal “echo” should be present in all the recordings, even if below the background noise level,” said Patty Lin, a postdoctoral candidate at ASU and another member of the team. “But when we add the signals together, that core reflection amplitude becomes visible, which lets us map the deep Moon.”
Weber told Universe Today that the shear waves do not penetrate fluid regions. “So while we have observed compression reflections off the solid inner core, we have not (as expected) observed shear reflections off the inner core, since that energy is reflected at the outer core layer.”
Recent studies suggested the Moon had a relatively small iron-rich core, sized between about 250 and 430 km, or roughly 15 to 25% of its 1,737.1 km mean radius. The new measurements put the core slightly larger.
“We have placed the core-mantle boundary at a radius of 330 km, roughly 19% of the Moon’s mean radius,” Weber said in an email.
The iron-rich core has a solid inner ball nearly 240 km (150 miles) in radius, and an 90 km (55-mile) thick outer fluid shell.
The new research also points to volatile-depleted interior, with the lunar core containing a small percentage of light elements such as sulfur, similar to light elements in Earth’s core – sulfur, oxygen and others.
The retooled 30-year-old data also appears to confirm the the leading theory of how the Moon formed.
“The presence of a melt layer and a molten outer core supports the widely-accepted large-impact model of lunar formation, which predicts that the Moon could have formed in a completely molten state,” Weber said.
Here’s the map of the future: a look where all the contestants in the Google Lunar X PRIZE intend to land on the Moon, in hopes of nabbing the $30 million in prizes available to the first privately funded teams to safely land a robot on the surface of the Moon. Dr. Philip J. Stooke of The University of Western Ontario has put together a this very nifty proposed landing site map based on published data from the Google Lunar X PRIZE Teams. According to Michael Doornbos from the Evadot website, assisting in the visualization, they will be updating the map regularly as the public information gets updated. Click on the image to see the original (and larger version) on Evadot.com
If you remember, the participants in the Google Lunar X PRIZE not only have to land their robot, but it also has to travel 500 meters over the lunar surface and send images and data back to the Earth. Teams must be at least 90% privately funded. The GLXP hopes to ignite a new era of lunar exploration by offering this largest international incentive prize of all time.
Find out more at The Google Lunar X PRIZE Website
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Love observing the Moon? There’s a new iPhone, iPod and iPad app that will provide everything you need to know. LunarCalc shows moon phases from any date between the years 1900 and 2200. It also provides ecliptic latitude and longitude, zodiacal position, distance from Earth, and apogee and perigee dates. The iPad version also provides moonrise, moonset and culmination, percent illuminated and lunation period.
LunarCalc is available in eight languages: English, Spanish, French, Italian, German Portuguese, Russian and Japanese.
Courtesy of the app’s creator, Fabio Rendelucci, Universe Today has 3 LunarCalc apps to giveaway. The first three correct answers to the following question will win. Post your answer in the comment section.
Question: When will the next total lunar eclipse take place?
To find out more or to buy the app, search “LunarCalc” in iTunes to download it.