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  • richardmitnick 12:08 pm on August 5, 2017 Permalink | Reply
    Tags: , , Lunar lava tubes, Lunar Nanobots, Moon Studies   

    From ESA: “Lunar Nanobot” 

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    European Space Agency

    1
    Lunar Nanobot
    Released 02/08/2017
    Copyright Lunatix

    This highly mobile, jumping Nanobot was designed by a team of space engineers challenged to develop a Moon mission that was not only technically viable but could also make a profit.

    The annual SpaceTech Master Programme of the Technical University of Graz, Austria trains space professionals to combine space and business engineering. ESA Director General Jan Woerner asked the 2016 participants to come up with a profitable business case to fit within ESA’s Moon Village concept.

    The eight SpaceTech 2016 participants presented the resulting Lunatix concept last month at ESA’s technical centre in Noordwijk, the Netherlands.

    “We want to enable you to leave your mark on the Moon,” explains ESA engineer Jorge Fiebrich. “Our ambition is to become the creative leader in lunar mobility experiences, through placing unique mobile platforms on the lunar surface.”

    The team designed these video camera-equipped Nanobots to tap into the $100 billion gaming market. After raising initial enthusiasm among Earth’s 1.8 billion gamers with controlling a virtual Nanobot on a simulated lunar surface, there will be the possibility to control real Nanobots on the Moon, in Pokemon Go!-style augmented reality scenarios.

    Science would be another business line, with the highly agile Nanobots able to probe sites of scientific interest such as lunar lava tubes.

    The Nanobots are designed to jump up to 3 m high and 10 m in distance in the one-sixth gravity of the Moon, which allows them to clear obstacles while offering an exciting gaming aspect.

    A series of Nanobots – formally known as Small Mobile Platforms – together with the Main Mobile Platform larger rover would be deployed on the Moon. Along with additional scientific payloads, the larger rover would recharge the Nanobots and give them shelter during the two-week lunar night.

    The SpaceTech team carried out a rigorous end-to-end design process, ensuring their robots could survive harsh lunar temperature swings and radiation and dust exposure, as well as continuously communicate with Earth – and their customers.

    “Through the Nanobots, humans will be experiencing the Moon in near-real time, with a two-way delay of around three seconds,” adds Jon Reijneveld, system engineer at Airbus Defence and Space. “They could be seen as the first inhabitants of the Moon Village.”

    Now the study has been completed, the participants are investigating plans to establish the company next year. For more information read the full summary here.

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 1:23 pm on January 15, 2017 Permalink | Reply
    Tags: A “planetary embryo” called Theia, , , Moon Studies,   

    From UCLA: “The moon is older than scientists thought, UCLA-led research team reports” 

    UCLA bloc

    UCLA

    January 11, 2017
    Stuart Wolpert

    1
    Apollo 14 astronaut Alan Shepard. A new UCLA study determined the age of the moon by analyzing minerals brought back by the 1971 mission. NASA.

    UCLA-led research team reports that the moon is at least 4.51 billion years old, or 40 million to 140 million years older than scientists previously thought.

    The findings — based on an analysis of minerals from the moon called zircons that were brought back to Earth by the Apollo 14 mission in 1971 — are published Jan. 11 in the journal Science Advances.

    The moon’s age has been a hotly debated topic, even though scientists have tried to settle the question over many years and using a wide range of scientific techniques.

    2
    Mélanie Barboni. Carolyn Crow

    “We have finally pinned down a minimum age for the moon; it’s time we knew its age and now we do,” said Mélanie Barboni, the study’s lead author and a research geochemist in UCLA’s Department of Earth, Planetary and Space Sciences.

    The moon was formed by a violent, head-on collision between the early Earth and a “planetary embryo” called Theia, a UCLA-led team of geochemists and colleagues reported in 2016.

    The newest research would mean that the moon formed “only” about 60 million years after the birth of the solar system — an important point because it would provide critical information for astronomers and planetary scientists who seek to understand the early evolution of the Earth and our solar system.

    That has been a difficult task, Barboni said, because “whatever was there before the giant impact has been erased.” While scientists cannot know what occurred before the collision with Theia, these findings are important because they will help scientists continue to piece together major events that followed it.

    It’s usually difficult to determine the age of moon rocks because most of them contain a patchwork of fragments of multiple other rocks. But Barboni was able to analyze eight zircons in pristine condition. Specifically, she examined how the uranium they contained had decayed to lead (in a lab at Princeton University) and how the lutetium they contained had decayed to an element called hafnium (using a mass spectrometer at UCLA). The researchers analyzed those elements together to determine the moon’s age.

    “Zircons are nature’s best clocks,” said Kevin McKeegan, a UCLA professor of geochemistry and cosmochemistry, and a co-author of the study. “They are the best mineral in preserving geological history and revealing where they originated.”

    The Earth’s collision with Theia created a liquefied moon, which then solidified. Scientists believe most of the moon’s surface was covered with magma right after its formation. The uranium–lead measurements reveal when the zircons first appeared in the moon’s initial magma ocean, which later cooled down and formed the moon’s mantle and crust; the lutetium–hafnium measurements reveal when its magma formed, which happened earlier.

    “Mélanie was very clever in figuring out the moon’s real age dates back to its pre-history before it solidified, not to its solidification,” said Edward Young, a UCLA professor of geochemistry and cosmochemistry and a co-author of the study.

    Previous studies concluded the moon’s age based on moon rocks that had been contaminated by multiple collisions. McKeegan said those rocks indicated the date of some other events, “but not the age of the moon.”

    The UCLA researchers are continuing to study zircons brought back by the Apollo astronauts to study the early history of the moon.

    Co-authors of the Science Advances study are Patrick Boehnke, a former UCLA graduate student who is now a University of Chicago postdoctoral scholar; Christopher Keller, a UC Berkeley postdoctoral scholar; Issaku Kohl, a UCLA research geochemist; and Blair Schoene, associate professor of geosciences at Princeton University.

    The research was funded by NASA, and Barboni received support from the Swiss National Science Foundation.

    See the full article here .

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    For nearly 100 years, UCLA has been a pioneer, persevering through impossibility, turning the futile into the attainable.

    We doubt the critics, reject the status quo and see opportunity in dissatisfaction. Our campus, faculty and students are driven by optimism. It is not naïve; it is essential. And it has fueled every accomplishment, allowing us to redefine what’s possible, time after time.

    This can-do perspective has brought us 12 Nobel Prizes, 12 Rhodes Scholarships, more NCAA titles than any university and more Olympic medals than most nations. Our faculty and alumni helped create the Internet and pioneered reverse osmosis. And more than 100 companies have been created based on technology developed at UCLA.

     
  • richardmitnick 10:58 am on November 1, 2016 Permalink | Reply
    Tags: , , Moon Studies,   

    From SETI Institute: “Did Early Earth Spin On Its Side?” 

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    SETI Institute

    October 31 2016
    Matija Cuk
    Email: mcuk@seti.org

    Media contact:

    Seth Shostak
    Tel: 650 960-4530
    Email: seth@seti.org

    New theoretical modeling of the ancient history of the Earth and the Moon suggests that the giant collision that spawned our natural satellite may have left Earth spinning very fast, and with its spin axis highly tilted.

    Computer simulations of what followed the collision, sometimes referred to as the “big whack,” show that, following this event, and as the young Moon’s orbit was getting bigger, the Earth lost much of its spin as well gained a nearly upright orientation with respect to the ecliptic. The simulations give new insight into the question of whether planets with big moons are more likely to have moderate climates and life.

    “Despite smart people working on this problem for fifty years, we’re still discovering surprisingly basic things about the earliest history of our world,” says Matija Cuk a scientist at the SETI Institute and lead researcher for the simulations. “It’s quite humbling.”

    Since the nineteenth century, scientists have known that the Moon is gradually moving away from Earth and that or planet’s spin is simultaneously slowing down. The cause is the ocean tides raised by the Moon which slowly dissipate energy as they move across the ocean basins. This energy has to come from somewhere, resulting in a slowing down of Earth’s rotation, with our days very slowly getting longer.

    Previous calculations done over many decades always concluded that the Moon formed close to Earth, which at the time had a rotation period of five hours. This calculation later became the basis of the giant impact theory, in which the Moon formed from debris generated in a collision between proto-Earth and a Mars-sized protoplanet.

    However, these calculations may have been missing some important physics. Four years ago, a paper in the journal Science by Cuk and Sarah Stewart (now at the University at California, Davis) suggested that post-impact Earth had a much faster spin, closer to 2 hours. A complex orbital interaction between the Moon and the Sun could have drained spin from the Earth-Moon system, causing an underestimate of Earth’s rotation. Note that a very fast early spin would eject more material from Earth into orbit during and just after the giant impact, producing a Moon that is similar in make-up to Earth’s mantle, as found by lab studies of lunar rocks.

    Since then, the plot has thickened as it was realized that tides within the Moon significantly affected its orbit during one part of its tidal migration. Today, the path of the Moon is tilted from Earths orbital plane by five degrees. Multiple theories have been offered to explain this tilt, but it was never considered significant enough to seriously challenge the idea that the Moon formed in a flat disk around the Earth. However, Erinna Chen and Francis Nimmo at the University of California, Santa Cruz reported in 2013 that internal friction due to tidal tugs by Earth should have greatly decreased the Moon’s orbital tilt over billions of years. Cuk and Stewart quickly realized a clear implication that the orbit of the Moon once had a large tilt to Earth’s orbit, changing the story of its history completely.

    “We’ve been calculating the past orbit of the Moon wrong for over fifty years now,” notes Cuk citing the work of then-doctoral student Chen. “We ignored the fact that tidal flexing within the Moon can decrease lunar orbital inclination.”

    In the paper just published in Nature, Cuk and Stewart, together with Douglas Hamilton of the University of Maryland and Simon Lock of Harvard, propose a new solution to the mystery of the lunar orbital tilt, one that also explains the Moon’s Earth-like make-up. They find that, if Earth originally spun on its side with the young Moon orbiting around its equator, solar gravitational forces could both take spin away from the system and tilt the Moon’s orbit.

    Planets bulge at their equator due to their spin, and for every planet there exists a special distance at which an orbiting satellite would feel roughly equal torque from the planet’s equatorial bulge and the distant Sun. But if the planet has an axial tilt over 70 degrees, the satellite’s orbit will suffer from a kind of orbital confusion.

    When the planet’s equator and its orbit are nearly perpendicular, the satellite becomes confused about which way is “up”, and its orbit becomes elongated due to Sun’s meddling. In the case of our Moon, the varying distance from Earth on its eccentric orbit then triggered strong tidal flexing within the Moon which fought back against the efforts of Earth’s tides to push it outward, resulting in a stalemate. Such a stalemate can last for millions of years, during which Earth kept losing its spin while the Moon did not go into a wider orbit. Instead, its orbit became more tilted.

    Once the Earth had lost enough of its original spin, the Moon broke out of this stalled state and continued its outward journey. But as the Moon left this special distance, its torque on Earth’s spin axis righted the previously highly-tilted Earth. Finally, as the Moon continued its orbital migration outward, tidal flexing within the Moon shrank its orbital inclination, bringing the lunar orbit closer to the plane of the planets.

    Despite the complexity of this story, computer calculations suggest that it is the only complete explanation so far for the current orbital and compositional properties of the Moon.

    “This work shows that there are multiple ways a planet could get a small axial tilt, making moderate seasons possible. We thought Earth was this way because of the direction of the giant impact 4.5 billion years ago, but it looks like Earth achieved this state later through a complex interaction with the Moon and the Sun,” Cuk says.

    “I wonder how many habitable Earth-like extrasolar planets also have a large Moon,” he asks.

    See the full article here .

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  • richardmitnick 8:17 am on November 1, 2016 Permalink | Reply
    Tags: , , Moon Studies   

    From COSMOS: “Moon-forming crash sent Earth into a spin: study” 

    Cosmos Magazine bloc

    COSMOS

    01 November 2016
    Belinda Smith

    Simulations show a collision strong enough to tilt our young planet almost on its side can explain how our moon ended up where it is today.

    1
    After a developing planet smashed into the primordial Earth, it nearly tilted the planet all the way over, simulations suggest. Ron Miller / Stocktrek Images / Getty Images

    There’s plenty about our familiar grey moon we still don’t know for sure. How did it form? Why is its orbit tilted slightly? And at around 380,000 kilometres distant, why is it so far away?

    Matija Ćuk from the SETI Institute in California and a team of US planetary scientists have an explanation. Using modelling and simulations, they conclude that the collision that formed the moon sent Earth almost rotating on its side.

    Over time, they write in Nature, interactions between the Earth, moon and sun smoothed out the whirling spin, leaving the duo in their current gravitational dance today.

    A leading theory of the moon’s genesis is the giant impact model. It states that some 4.5 billion years ago, the young Earth collided with a developing planet, Theia.

    Dust and rubble formed a disc around what was left of the Earth, which clumped together to become the moon.

    “But this scenario does not quite work if the Earth’s spin axis was tilted at the 23.5 ° angle we see today,” says Douglas Hamilton from the University of Maryland and co-author of the study.

    Physics says the debris – and thus, the moon – should have gathered into a ring around Earth’s equator. Then as tidal forces pushed the moon away, the moon should have made its way into an ecliptic plane, which is in the same plane as the Earth’s orbit around the sun.

    Instead, the moon’s orbit is tilted five degrees away from the ecliptic plane today.

    So what happened?

    Ćuk and his colleagues ran different moon-forming scenarios. The ones that ended up with an Earth-moon system most like we see today involved a collision that sent the Earth spinning extremely fast – as much as twice the rate predicted by other models.

    The impact also knocked the Earth’s tilt way off between 60 and 80 ° – almost on its side.

    The newborn moon also started off very close to Earth, tracking closely with the Earth’s equator, but then drifted away. As it approached15 times its initial distance, the sun exerted its own influence over the moon’s orbit.

    A highly tilted, fast-spinning Earth and an outward-migrating moon probably contributed to the moon’s current strange orbit, the researchers conclude.

    Hamilton acknowledges that the model isn’t perfect and doesn’t answer all questions about the moon’s orbit.

    But “what we have now is a model that is more probable and works more cleanly than previous attempts”, he says.

    “We think this is a significant improvement that gets us closer to what actually happened.”

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  • richardmitnick 11:24 am on October 13, 2016 Permalink | Reply
    Tags: , , Moon Studies, , NASA/Lunar Reconnaissance Orbiter   

    From Goddard: “Earth’s Moon Hit by Surprising Number of Meteoroids” 

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    NASA Goddard Space Flight Center

    Oct. 13, 2016
    Nancy Jones
    nancy.n.jones@nasa.gov

    Bill Steigerwald
    william.a.steigerwald@nasa.gov

    NASA Goddard Space Flight Center, Greenbelt, Maryland
    301-286-0039 / x-5017

    Last Updated: Oct. 13, 2016
    Editor: Bill Steigerwald

    The moon experiences a heavier bombardment by small meteoroids than models had predicted, according to new observations from NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft.

    NASA/Lunar Reconna
    NASA/Lunar Reconnaissance Orbiter

    The result implies that lunar surface features thought to be young because they have relatively few impact craters may be even younger than previous estimates.

    The finding also implies that equipment placed on the moon for long durations — such as a lunar base — may have to be made sturdier. While a direct hit from a meteoroid is still unlikely, a more intense rain of secondary debris thrown out by nearby impacts may pose a risk to surface assets.


    Access mp4 video here .
    After simulating the distant view of a new impact, the camera zooms up to the surface to show actual before/after images of a new 12-meter crater taken by the Lunar Reconnaissance Orbiter narrow-angle camera. Credits: NASA/GSFC/Ernie Wright

    “Before the launch of the Lunar Reconnaissance Orbiter, it was thought that churning of the lunar regolith (soil) from meteoroid impacts typically took millions of years to overturn the surface down to 2 centimeters (about 0.8 inches),” said Emerson Speyerer of Arizona State University, Tempe. “New images from the Lunar Reconnaissance Orbiter Camera (LROC) are revealing small surface changes that are transforming the surface much faster than previously thought.” Speyerer is lead author of a paper about this research in the Oct. 13 issue of the journal Nature.

    “The newly determined churning rate means that the Apollo astronaut tracks will be gone in tens of thousands of years rather than millions,” said Mark Robinson of Arizona State University, a co-author.

    2
    One of the first steps taken on the Moon, this is an image of Buzz Aldrin’s bootprint from the Apollo 11 mission. Neil Armstrong and Buzz Aldrin walked on the Moon on July 20, 1969. Credits: NASA

    LRO went into lunar orbit in June of 2009 and has acquired an extensive set of high-resolution images of the surface, including pairs of images of the same areas taken at different times. Using these before-and-after images (temporal pairs) acquired by the LROC Narrow Angle Camera (NAC), the team identified over 200 impact craters that formed during the LRO mission, ranging in size from about 10 to 140 feet (approximately 3 to 43 meters) in diameter.

    3
    Temporal ratio image formed from two LROC Narrow Angle Camera images (after image divided by the before image) revealing a new 12 meter (~40 foot) diameter impact crater (Latitude: 36.536°N; Longitude: 12.379°E) formed between 25 October 2012 and 21 April 2013, scene is 1300 meters (~4200 feet) wide. New crater and its continuous ejecta are seen as the small bright area in the center, dark areas are the result of material blasted out of the crater to distances much further than previously thought. Credits: NASA/GSFC/Arizona State University

    Since impact craters accumulate over time, a heavily cratered surface is older than a region with fewer craters. Knowing the number of craters that form each year is important when estimating absolute ages of the youngest regions. By analyzing the number, size distribution, and the time between each NAC temporal pair, the team estimated the contemporary cratering rate on the moon. During the search, they identified about 30 percent more new craters than anticipated by previous cratering models.

    “With this potentially higher impact rate, features with young model ages derived using crater counts and the standard rate may in fact be even younger than previously thought,” said Speyerer. “However, to be certain, we need several more years of observations and new crater discoveries.”

    In addition to discovering new impact craters, the team observed over 47,000 small surface changes, which they call splotches. They are most likely caused by small impacts, according to Speyerer. There are dense clusters of these splotches around new impact sites suggesting that many splotches may be secondary surface changes caused by material thrown out from the primary impact event.

    The team estimated their accumulation over time and from measuring their size they inferred how deeply each splotch dug up the surface and thus how long it takes to effectively churn the upper few centimeters (approximately an inch) of the regolith. The team found that 99 percent of the surface would be overturned by splotch formation after about 81,000 years. This rate is over 100 times faster than previous models that considered overturn from micrometeorite impacts alone, and ignored the effects of secondary impacts.

    “The increased churning rate will be important information for future designers of moon bases, said Speyerer. “Surface assets will have to be designed to withstand impacts from small particles moving at up to 500 meters per second (about 1,600 feet per second or 1,100 miles per hour).”

    The team also found that the new impact craters are surrounded by complex reflectance patterns related to material ejected during crater formation. Many of the larger impact craters — those greater than 10 meters in diameter — exhibit up to four distinct bright or dark reflectance zones.

    The research was funded by the LRO project. The Lunar Reconnaissance Orbiter Camera was developed at Arizona State University in Tempe. LRO is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, as a project under NASA’s Discovery Program. The Discovery Program is managed by NASA’s Marshall Spaceflight Center in Huntsville, Alabama, for the Science Mission Directorate at NASA Headquarters in Washington.

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    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.
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  • richardmitnick 9:11 pm on September 12, 2016 Permalink | Reply
    Tags: , , , Moon Studies   

    From GIZMODO: “We Were Wrong About Where the Moon Came From” 

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    GIZMODO

    9.12.16
    Ria Misra

    1
    Artist’s concept of moon-Earth crash (Image: Dana Berry/SwRI)

    The moon is our almost constant frenemy in space, lighting our nights and spoiling our star-views in equal turns. But now, new measurements from Apollo-era moon rocks suggest that the moon and Earth had a much more savage past than we knew.

    A new paper out today in Nature says that the moon formed as a result of a more violent space collision than previously believed. Since the 1970s, many researchers have championed a theory in which the moon was created from thrown-off debris when a Mars-sized body grazed Earth in a relatively low-contact collision. Instead, the researchers say new evidence shows that the impact was more “like a sledgehammer hitting a watermelon.”

    The old theory of the moon’s origin—in which it formed from debris from a grazing collision—neatly explains both the moon’s size and orbital position. But a test on some lunar rocks from the Apollo mission revealed something odd which that theory couldn’t explain.

    “We’re still remeasuring the old Apollo samples from the the ‘70s, because the tech has been developing in recent years. We can measure much smaller differences between Earth and the moon, so we found a lot of things we didn’t find in the 1970s,” Kun Wang, an assistant professor at Washington University who is the lead author of the paper told Gizmodo. “The old models just could not explain the new observations.”

    If the four-decade old theory were correct, then researchers would expect to find that well over half of the moon’s material had come from that Mars-sized body that scraped Earth to form the moon. But the researchers weren’t finding signs of that in the samples; instead, chemical analyses on the samples were returning isotopic compound readings that were nearly identical.

    They started to do more and more advanced tests to try and pinpoint any differences in the signatures. They finally found one—but one that suggested that the samples’ origins were even more tightly connected than previously expected.

    The isotope signatures were the same, except for more of a heavy-potassium isotope in the lunar samples which would have required incredibly hot temperatures to separate out. A violent collision between the Earth and the Mars-sized impactor could have caused those incredibly high temperatures. In this model, the temperatures were so high and the force so powerful that the impactor and even much of Earth vaporized on contact. That vapor then expanded out over an area 500 times the size of the Earth before finally cooling and condensing into the moon.

    “We need a much, much bigger impact to form a moon according to our study,” explained Wang. “The giant impact itself should be called extremely giant impact. The amount of energy required isn’t even close.”

    This new data doesn’t just change our conception of how the moon was formed, though. It also suggests an early solar system that was much more volatile than we knew—and it could be just the beginning of what new analyses on old lunar samples could teach us.

    “Everything we know about the early solar system is from our study of meteorites and lunar samples, all those really really old rocks,” said Wang. “It has changed our understanding of the early solar system, it’s much more violent than we thought.”

    The researchers will continue to study the Apollo lunar samples to try and pull yet more clues from them. Even now, they suspect that these samples that we’ve been holding on to for decades could have more secrets to reveal.

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  • richardmitnick 12:52 pm on August 12, 2016 Permalink | Reply
    Tags: , , , Moon Studies, ,   

    From Smithsonian: “New Moon-Formation Theory Also Raises Questions About Early Earth” 

    smithsonian
    smithsonian.com

    8.12.16
    Nola Taylor Redd

    A new model of the impact that created the moon might upend theories about earth, too

    1
    Visualization of the giant impact that formed the moon (William Hartmann)

    A new theory about how the moon formed might also tweak our understanding of early life on Earth.

    The presence of gold and platinum in Earth’s mantle has previously been assumed to be the result of a heavy shower of meteors raining down on early Earth, but new research suggests another source—one enormous impact with the object that crashed into the planet to create the moon.

    Around 4 billion years ago the Earth was under constant attack, according to geophysicists. Asteroids and meteors continuously smashed into the planet for about 100 million years, a period known as the Late Heavy Bombardment. Any life on the planet at that time would be in constant peril.

    We know about these impacts not because of the craters they left—erosion and plate tectonics have long spirited those away—but because of the presence of certain metals in the Earth’s mantle. The pockmarked surface of the moon, which is not tectonically active, also helps bolster this theory.

    But new research suggests that the bombardment may have been milder than expected, because the metals found in Earth’s mantle could instead be from the moon-forming impact, about 500 million years earlier.

    Early in the life of the solar system, a growing world known to scientists as Theia collided with the young Earth. The violent impact liquefied Earth’s outer layers and pulverized Theia, creating a ring of debris that swirled around the scarred world. Iron from Theia’s core drew together to form the heart of the moon. The remaining heavy material rained back down on Earth, and gravity drew the lighter components together to create the moon.

    But new research suggests not all of Theia’s iron built the lunar core. Instead, some may have settled on Earth’s crust, and was later drawn into the mantle through plate tectonics. Elements such as gold and platinum, which are drawn to iron, may have been pulled into the mantle along with it. Such elements are sparse in the lunar mantle, presumably because all of the iron delivered to the moon created its core while Earth’s original core remained intact after the collision.

    That could mean good news for life on the early Earth. If Theia’s core brought in traces of iron that attracted scarcer, iron-loving elements, the rain of asteroids and meteors couldn’t have been as heavy as previously estimated.

    “The Earth is not going to be completely unhabitable for a long period of time because the bombardment is relatively benign,” says Norman Sleep, a geophysicist at Stanford University. Sleep investigated the idea that Theia could have brought platinum and similar elements to Earth’s mantle, comparing it with previous suggestions that meteors delivered the material. In a recent paper published in the journal Geochemistry, Geophysics, Geosystems, he found that Theia could have brought in enough iron-loving elements to suggest later bombardment was milder than previously considered.

    “It was certainly not anything we would survive, but we’re dealing with microbes,” he says.

    However, without a heavy bombardment of meteorites, a new problem arises. The collision between Theia and the young Earth would have vaporized any water on the planet. The leading theory for how Earth got its water back is via collisions with water-carrying meteorites, but meteorites would also have delivered more iron-loving elements along with iron, leaving behind too much gold and platinum than measured. That means Sleep’s calculations would require another method of bringing water to the planet.

    That doesn’t make the theory a deal-breaker. “There’s no guarantee that there’s one event that solves every problem,” says Tim Swindle, who studies planetary materials at the University of Arizona. Water could have come from another source unrelated to Theia.

    Figuring out exactly what happened in the early life of Earth and its moon may require a return to our satellite. “We’ve got to go back to the moon and get a better handle on the age of the basins,” Swindle says, especially those on the back side of the moon. “We might be able to get an age with a rover that could answer the questions, but I think we’d do better to bring the samples back.” That doesn’t necessarily mean humans have to be onboard the lunar mission, but, as Swindle points out, people do a great job.

    Sleep agrees, calling for a visit to the South Pole Aiken basin, the largest and oldest of those on the moon. That basin has never been sampled, and should provide insight into the timing of the bombardment, which would give clues into how much material rained down on Earth.

    According to Edward Young, a planetary scientist at the University of California at Los Angeles, the biggest result of Sleep’s research is the mental shift it requires for the scientists studying Earth and the moon. “I think what he’s doing is exposing the soft underbelly of what we do,” Young says, adding that geochemical arguments are filled with basic assumptions of the processes that go into building the Earth and moon. “He’s challenging some of those assumptions.”

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    Smithsonian magazine and Smithsonian.com place a Smithsonian lens on the world, looking at the topics and subject matters researched, studied and exhibited by the Smithsonian Institution — science, history, art, popular culture and innovation — and chronicling them every day for our diverse readership.

     
  • richardmitnick 1:11 pm on May 12, 2016 Permalink | Reply
    Tags: , , , Lunar Ice Drill, Moon Studies   

    From ESA: “Lunar ice drill” 

    ESA Space For Europe Banner

    European Space Agency

    1
    Copyright ESA/Finmeccanica

    11/05/2016

    A drill designed to penetrate 1–2 m into the lunar surface is envisaged by ESA to fly to the Moon’s south pole on Russia’s Luna-27 lander in 2020.

    “It is an essential part of a science and exploration package being developed to reach, extract and analyse samples from beneath the surface in the Moon’s south polar region,” explains lunar exploration systems engineer Richard Fisackerly.

    “This region is of great interest to lunar researchers and explorers because the low angle of the Sun over the horizon leads to areas of partial or even complete shadow. These shadowed areas and permanently dark crater floors, where sunlight never reaches, are believed to hide water ice and other frozen volatiles.”

    Developed by Finmeccanica in Nerviano, Italy, the drill would first penetrate into the frozen ‘regolith’ and then deliver the samples to a chemical laboratory, which is being developed by the UK’s Open University.

    The development team has tested the drill design with simulated lunar soil cooled to –140°C (typical of the expected landing site of Luna-27) but the permanently shadowed regions of the Moon are known to be even colder, at down to –240°C.

    The drill system plus laboratory are collectively known as Prospect: Platform for Resource Observation and in-Situ Prospecting in support of Exploration, Commercial exploitation & Transportation.

    Prospect is one of the packages being developed by ESA for flight to the Moon as part of cooperation on Russia’s lunar programme. Pilot – Precise Intelligent Landing using On-board Technology – is an autonomous precision landing system incorporating ‘laser radar’ lidar for hazard detection and avoidance.

    These packages are being developed by ESA’s Directorate of Human and Robotic Exploration and will be proposed for approval to fly by ESA’s Council of European Ministers in December 2016.

    See the full article here .

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    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

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  • richardmitnick 10:47 am on April 4, 2016 Permalink | Reply
    Tags: , , , Moon Studies   

    From COSMOS: “No Moon, no magnetic field, no life on Earth: study” 

    Cosmos Magazine bloc

    COSMOS

    1 Apr 2016
    Belinda Smith

    Without the Moon, there would be no life on Earth, French scientists claim.

    Moon of Earth. Alfredo Garcia, Jr
    Moon of Earth. Alfredo Garcia, Jr

    The gravitational push-pull of the Moon on iron deep inside Earth keeps it hot and molten. And a liquid core is needed to generate a magnetic field, which forms a protective shield against blasts of particles from the Sun.

    Denis Andrault from Blaise Pascal University in Clermont-Ferrand, France, and colleagues propose the Earth’s heated interior should have dropped by about 3,000 ºC over the past four billion years or so, but has instead remained almost constant – all because of the Moon.

    Their story, published in Earth and Planetary Science Letters, begins around 4.3 billion years ago, or 60 million years after the Earth’s birth.

    A massive collision turned the planet molten, with some bits flung out to clump together and become the Moon. Back then, the core of the Earth would’ve sat around 6,800 Kelvin, or around 6,500 ºC.

    After around a million years of cooling, Earth developed a thin crust and the beginnings of a mantle – a thick layer of hot rock between crust and core. The core, at this point all liquid, started to produce a magnetic field. This, the scientists write, was a stage of “thermally driven dynamo” as heat rose from the centre of the core towards the surface of the planet, churning parallel to Earth’s axis of rotation.

    Following another billion years or so, the core started to solidify in its centre, while the liquid outer core kept churning and the mantle cooled. Then, by a billion years ago or so, the temperature of the core should have dropped 3,000 ºC.

    But it didn’t, Andrault and colleagues claim – instead, it dropped only 300 ºC.

    In the most recent billion years, the temperature was propped up by tidal forces from the Moon squishing and stretching the mantle, along with forces from our orbit around the Sun. This “mechanical forcing”, they write, “could have started to induce core motions as soon as the Moon was formed”.

    They created a thermal model of the deep Earth’s geodynamo – an “orbitally driven dynamo” – and showed the Moon’s effects made up for the heat lost into space.

    And because nothing’s perfect – not Earth’s slightly wobbly rotation or the Moon’s orbit – small irregularities can cause fluctuations in the geodynamo. Pulses of heat may have melted parts of the deep mantle which, in turn, may have led to major volcanic eruptions on the surface.

    The deep Earth may not be cooling down

    Science team:
    Denis Andrault, a; Julien Monteuxa, a; Michael Le Bars ,b; Henri Samuel, c
    Affiliations:
    a Laboratoire Magmas et Volcans, CNRS-OPGC-IRD, Université Blaise Pascal, Clermont-Ferrand, France
    b CNRS, Aix-Marseille Université, Ecole Centrale Marseille, IRPHE, UMR 7342, Marseille, France
    c Institut de Recherche en Astrophysique et Planétologie, CNRS, Université Paul Sabatier, Toulouse, France

    See the full article here .

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  • richardmitnick 9:20 pm on September 15, 2015 Permalink | Reply
    Tags: , , Moon Studies, , NASA LRO   

    From Goddard: “NASA’s LRO Discovers Earth’s Pull is ‘Massaging’ our Moon” 

    NASA Goddard Banner
    Goddard Space Flight Center

    Sep. 15, 2015
    Nancy Neal-Jones / William Steigerwald
    NASA Goddard Space Flight Center, Greenbelt, Maryland
    301-286-0039

    1
    The gravitational forces the Moon and Sun exert are responsible for Earth’s rising and falling tides. Earth’s gravity also exerts forces on the Moon in the form of solid body tides that distort its shape. The Moon is slowly receding away from Earth and forces build as the Moon’s tidal distortion diminishes with distance and its rotation period slows with time. These tidal forces combined with the shrinking of the Moon from cooling of its interior have influenced the pattern of orientations in the network of young fault scarps.
    Credits: NASA/LRO/Arizona State University/Smithsonian Institution

    In August, 2010, researchers using images from LRO’s Narrow Angle Camera (NAC) reported the discovery of 14 cliffs known as “lobate scarps” on the moon’s surface, in addition to about 70 previously known from the limited high-resolution Apollo Panoramic Camera photographs. Due largely to their random distribution across the surface, the science team concluded that the moon is shrinking.

    NASA Lunar Reconnaisence Orbiter
    NASA Lunar Reconnaissance Orbiter

    2
    Thousands of young, lobate thrust fault scarps have been revealed in Reconnaissance Orbiter Camera images (LROC). Lobate scarps like the one shown here are like stair-steps in the landscape formed when crustal materials are pushed together, break and are thrust upward along a fault forming a cliff. Cooling of the still hot lunar interior is causing the Moon to shrink, but the pattern of orientations of the scarps indicate that tidal forces are contributing to the formation of the young faults. Credits: NASA/LRO/Arizona State University/Smithsonian Institution

    These small faults are typically less than 6.2 miles (10 kilometers) long and only tens of yards or meters high. They are most likely formed by global contraction resulting from cooling of the moon’s still hot interior. As the interior cools and portions of the liquid outer core solidify, the volume decreases; thus the moon shrinks and the solid crust buckles.

    Now, after more than six years in orbit, the Lunar Reconnaissance Orbiter Camera (LROC) has imaged nearly three-fourths of the lunar surface at high resolution, allowing the discovery of over 3,000 more of these features. These globally distributed faults have emerged as the most common tectonic landform on the moon. An analysis of the orientations of these small scarps yielded a surprising result: the faults created as the moon shrinks are being influenced by an unexpected source—gravitational tidal forces from Earth.

    Global contraction alone should generate an array of thrust faults with no particular pattern in the orientations of the faults, because the contracting forces have equal magnitude in all directions. “This is not what we found,” says Smithsonian senior scientist Thomas Watters of the National Air and Space Museum in Washington. “There is a pattern in the orientations of the thousands of faults and it suggests something else is influencing their formation, something that’s also acting on a global scale — ‘massaging’ and realigning them.” Watters is lead author of the paper describing this research published in the October issue of the journal Geology.

    The other forces acting on the moon come not from its interior, but from Earth. These are tidal forces. When the tidal forces are superimposed on the global contraction, the combined stresses should cause predictable orientations of the fault scarps from region to region. “The agreement between the mapped fault orientations and the fault orientations predicted by the modeled tidal and contractional forces is pretty striking,” says Watters.

    “The discovery of so many previously undetected tectonic features as our LROC high-resolution image coverage continues to grow is truly remarkable,” said Mark Robinson of Arizona State University, coauthor and LROC principal investigator. “Early on in the mission we suspected that tidal forces played a role in the formation of tectonic features, but we did not have enough coverage to make any conclusive statements. Now that we have NAC images with appropriate lighting for more than half of the moon, structural patterns are starting to come into focus.”

    The fault scarps are very young – so young that they are likely still actively forming today. The team’s modeling shows that the peak stresses are reached when the moon is farthest from Earth in its orbit (at apogee). If the faults are still active, the occurrence of shallow moonquakes related to slip events on the faults may be most frequent when the moon is at apogee. This hypothesis can be tested with a long-lived lunar seismic network.

    3
    The map shows the locations of over 3,200 lobate thrust fault scarps (red lines) on the Moon. The black double arrows show the average orientations of the lobate scarps sampled in areas with dimensions of 40° longitude by 20° latitude and scaled by the total length of the fault scarps in the sampled areas. The pattern of the black double arrows (orientation vectors) indicates that the fault scarps do not have random orientations as would be expected if the forces that formed them were from global contraction alone. Mare basalt units are shown in tan. Credits: NASA/LRO/Arizona State University/Smithsonian Institution

    “With LRO we’ve been able to study the moon globally in detail not yet possible with any other body in the solar system beyond Earth, and the LRO data set enables us to tease out subtle but important processes that would otherwise remain hidden,” said John Keller, LRO Project Scientist at NASA’s Goddard Space Flight Center, Greenbelt, Maryland.

    4
    A prominent lobate fault scarp in the Vitello Cluster is one of thousands discovered in Lunar Reconnaissance Orbiter Camera images (LROC). Topography derived from the LROC Narrow Angle Camera (NAC) stereo images shows a degraded crater has been uplift as the fault scarp has formed (blues are lower elevations and reds are higher elevations). Boulders in the crater have aligned in rows that parallel the orientation of the fault scarp. Credits: NASA/LRO/Arizona State University/Smithsonian Institution

    5
    A nadir (top) and perspective view (bottom) of a prominent lobate fault scarp in the Vitello Cluster, one of thousands discovered in Lunar Reconnaissance Orbiter Camera images (LROC). In the perspective view, the Narrow Angle Camera (NAC) image is draped over topography derived from NAC stereo images. A degraded crater has been uplift as the fault scarp has formed. Boulders in the crater have aligned in rows that parallel the orientation of the fault scarp. Credits: NASA/LRO/Arizona State University/Smithsonian Institution

    Launched on June 18, 2009, LRO has collected a treasure trove of data with its seven powerful instruments, making an invaluable contribution to our knowledge about the moon. LRO is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, under the Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville for the Science Mission Directorate at NASA Headquarters in Washington, DC.

    See the full article here .

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    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    NASA Goddard Campus
    NASA/Goddard Campus
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