South Polar Region of Vesta - Enhanced View. NASA's Dawn spacecraft obtained this image centered on the south pole of Vesta with its framing camera on July 18, 2011. The image has been enhanced to bring out more surface details. It was taken from a distance of about 6,500 miles (10,500 kilometers) away from the protoplanet Vesta. The smallest detail visible is about 1.2 miles (2.0 km). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA. Enhanced and annotated by Ken Kremer
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NASA’s Dawn Asteroid Orbiter is now spiraling down ever closer to the protoplanet Vesta – since arriving on July 16 – and capturing magnificent new high resolution images of the huge impact basin at the South Pole that dominates the surface. See enhanced image here.
The Dawn team just released a new image taken by the framing camera on July 18 as the orbiter flew from the day side to the night side at an altitude of 10,500 kilometers above Vesta, the second most massive body in the main Asteroid Belt between Mars and Jupiter.
NASA's Dawn spacecraft obtained this image centered on the south pole with its framing camera on July 18, 2011. It was taken from a distance of about 6,500 miles (10,500 kilometers) away from the protoplanet Vesta. The smallest detail visible is about 1.2 miles (2.0 km). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
“I find this picture very dramatic !” exclaimed Dr. Marc Rayman, Dawn Chief Engineer from the NASA’s Jet Propulsion Laboratory in Pasadena, Calif., in an interview with Universe Today.
“Dawn acquired this image after it had flown past the terminator and its orbit began taking it over the night side of Vesta.”
“After having this view, the spacecraft resumed gradually spiraling around its new home, heading for survey orbit where it will begin intensive observations of Vesta,” Rayman told me.
Dawn will reach the initial science survey orbit in early August, approximately 1700 miles above the battered surface. Vesta turns on its axis once very five hours and 20 minutes.
Vesta suffered an enormous cosmic collision eons ago that apparently created a gigantic impact basin in the southern hemisphere and blasted enormous quantities of soil, rocks and dust into space. Some 5% of all meteorites found on Earth originate from Vesta.
“The south pole region was declared to be a large impact basin after the Hubble Space Telescope (HST) data and images were obtained,” elaborated Prof. Chris Russell, Dawn Principal Investigator from UCLA.
“Now that we have higher resolution images we see that this region is unlike any other large impact on a small body but much of our experience here is on icy bodies of similar size,” Russell told me.
Dawn’s new images of Vesta taken at close range from just a few thousand miles away, now vastly exceed those taken by Hubble as it circled in Earth orbit hundreds of millions of miles away and may cause the science team to reevaluate some long held theories.
“The team is looking forward to obtaining higher resolution data over this region to look for confirmatory evidence for the impact hypothesis. They are not yet willing to vote for or against the HST interpretation. Needless to say the team got very excited by this image,” said Russell.
Dawn will orbit Vesta for one year before heading to its final destination, the Dwarf Planet Ceres.
Simulated View of Vesta from Dawn on July 23, 2011. Credit: NASA
Enhanced - First Vesta Vista Captured in orbit by Dawn on July 17, 2011. This image taken by the framing camera on July 17, 2011 has been enhanced to bringouitr further detail. It was taken from a distance of about 9,500 miles (15,000 kilometers) away from the protoplanet Vesta. Each pixel in the image corresponds to roughly 0.88 miles (1.4 kilometers). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA. Enhanced and annotated by Ken Kremer
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The first ever Vesta Vista snapped from the protoplanets orbit has been transmitted back through 117 million miles of space to eager eyes waiting on Earth. Although Vesta had been observed by telescopes on Earth and in space for more than two centuries since its discovery, only scant detail on its surface could be discerned until today.
NASA’s Dawn spacecraft took the new photo of the giant asteroid Vesta on July 17 – enhanced version shown above – less than 2 days after making space history as the first probe ever to enter orbit about an object in the main Asteroid Belt. The team also released their first 3 D image of Vesta. Read my orbital capture story here and see the original NASA image below.
“I think it is truly thrilling to be turning what was little more than a fuzzy blob for two centuries into a fascinating alien world,” said Dawn Chief Engineer Marc Rayman in a new post orbit interview with Universe Today.
Vesta is 330 miles (530 kilometers) in diameter and the second most massive object in the Asteroid Belt between Mars and Jupiter.
“And the closer Dawn gets to Vesta, the more exotic and intriguing the pictures become !,” added Rayman.
First Vesta Vista Captured in orbit by Dawn on July 17, 2011
NASA's Dawn spacecraft obtained this image with its framing camera on July 17, 2011. It was taken from a distance of about 9,500 miles (15,000 kilometers) away from the protoplanet Vesta. Each pixel in the image corresponds to roughly 0.88 miles (1.4 kilometers). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Enhanced image above
Dawn was captured into orbit at an altitude of 9,900 miles (16,000 km) at 1 a.m. EDT on July 16 according to Rayman, of the Jet Propulsion Lab in Pasadena, Calif. and is now slowly descending over the next few weeks.
“The spacecraft remains healthy, and our spiral down to Vesta is going well,” Rayman told me.
The new photo from orbit is nearly centered on the south pole which suffered a devastation cosmic collision eons ago. That blast sent huge plumes of ejecta streaming out, including towards Earth. About 5% of all known meteorites stem from Vesta.
“The south pole is a bulging feature in the images,” said Prof. Chris Russll, Dawn’s Science Principal Investigator of UCLA in an interview.
“The pole is not centered on this feature but is close to it. We have not finalized our determination of the pole but are close to a ‘final’ answer. We are not making interpretations at this point because the greater resolution that is coming will make all today’s speculations moot,” Russell stated.
Vesta Sizes Up
This composite image shows the comparative sizes of nine asteroids visited by Earthly spaceships. Up until now, Lutetia, with a diameter of 81 miles (130 kilometers), was the largest asteroid visited by a spacecraft, which occurred during a flyby. Vesta, which is also considered a protoplanet because it's a large body that almost became a planet, dwarfs all other small bodies in this image, with its diameter sizing up at approximately 330 miles (530 kilometers). Credit: NASA/JPL-Caltech/JAXA/ESA
By early August, Dawn will have gently been nudged into its initial science observation orbit at an altitude of approximately 1700 miles above the scarred surface of newly discovered mountains, craters, grooves, scarps and more.
During the approach phase, the Dawn team will accomplish multiple tasks with its onboard systems and three science instruments; including the search for possible moons, observing Vesta’s physical properties and obtaining calibration data.
But don’t expect a continuous stream of new pictures, according to Russell.
“We will not have a steady stream of images until we are in one of our
three science phases,” Russell told me. “When we are in transit from one place to another we thrust, stop, turn, image, turn, transmit, turn, thrust, and several days later repeat. All time spent not thrusting is time taken away from science later.”
“The next image is scheduled to be snapped on Saturday July 23.”
We will learn a lot more at the next press conference scheduled to take place on Monday August 1 from JPL.
Dawn will spend one year orbiting around Vesta and collecting high resolution mapping images, determining the chemical composition and measuring its gravity field. Then it will fire its ion thrusters to propel the probe to a second destination, the dwarf planet Ceres, arriving in February 2015.
The Asteroid Belt is one of the last unexplored regions of our solar system.
“We are beginning the study of arguably the oldest extant primordial surface in the solar system,” elaborated Russell in a NASA statement. “This region of space has been ignored for far too long. So far, the images received to date reveal a complex surface that seems to have preserved some of the earliest events in Vesta’s history, as well as logging the onslaught that Vesta has suffered in the intervening eons.”
An Enhanced View of Vesta's South Polar Region. This image, taken by the framing camera instrument aboard NASA's Dawn spacecraft, shows the south polar region of this object, which has a diameter of 330 miles (530 kilometers). The image was taken through the clear filter on July 9, 2011, as part of a rotation characterization sequence, and it has a scale of about 2.2 miles (3.5 kilometers) per pixel. To enhance details, the resolution was enlarged to 0.6 miles (1 kilometer) per pixel. This region is characterized by rough topography, a large mountain, impact craters, grooves and steep scarps. The original image was map-projected, centered at 55 degrees southern latitude and 210 degrees eastern longitude. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDAAnaglyph Image of Vesta's South Polar Region
This anaglyph image of the south polar region of the asteroid Vesta was put together from two clear filter images, taken on July 9, 2011 by the framing camera instrument aboard NASA's Dawn spacecraft. Each pixel in this image corresponds to roughly 2.2 miles (3.5 kilometers). The anaglyph image shows the rough topography in the south polar area, the large mountain, impact craters, grooves, and steep scarps in three dimensions. The diameter of Vesta is about 330 miles (530 kilometers). Use red-green (or red-blue) glasses to view in 3-D. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA3 D Viewing Demo
STS-135 twins show the right and wrong way to wear nifty 3-D glasses. Remember; red on the left (Ken Kremer – at right & Mike Barrett – at left, wrong) – backdropped by Space Shuttle Atlantis at the base of Launch Pad 39A at the Kennedy Space Center. Credit: Julian Leek
Hubble and Dawn Views of Vesta. These views of the protoplanet Vesta were obtained by NASA's Dawn spacecraft and NASA's Hubble Space Telescope. The image from Dawn, on the left, is a little more than twice as sharp as the image from Hubble, on the right. The image from Hubble, which is in orbit around the Earth, was obtained on May 14, 2007, when Vesta was 109 million miles (176 million kilometers) away from Earth. Dawn's image was taken on June 20, 2011, when Dawn was about 117,000 miles (189,000 kilometers) away from Vesta. The framing cameras were developed and built under the leadership of the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/PSI and NASA/ESA/STScI/UMd
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A new world in our Solar System is about to be unveiled for the first time – the mysterious protoplanet Vesta, which is the second most massive object in the main Asteroid Belt between Mars and Jupiter.
NASA’s Dawn Asteroid orbiter has entered its final approach phase to Vesta and for the first time is snapping images that finally exceed those taken several years ago by the iconic Hubble Space Telescope.
“The Dawn science campaign at Vesta will unveil a mysterious world, an object that can tell us much about the earliest formation of the planets and the solar system,” said Jim Adams, Deputy Director, Planetary Science Directorate at NASA HQ at a briefing for reporters.
Vesta holds a record of the earliest history of the solar system. The protoplanet failed to form into a full planet due to its close proximity to Jupiter.
Check out this amazing NASA approach video showing Vesta growing in Dawn’s eyes. The compilation of navigation images from Dawn’s framing camera spans about seven weeks from May 3 to June 20 was released at the NASA press briefing by the Dawn science team.
Dawn’s Approach to Vesta – Video
Best View from Hubble – Video
Be sure to notice that Vesta’s south pole is missing due to a cataclysmic event eons ago that created a massive impact crater – soon to be unveiled in astounding clarity. Some of that colossal debris sped toward Earth and survived the terror of atmospheric entry. Planetary Scientists believe that about 5% of all known meteorites originated from Vesta, based on spectral evidence.
After a journey of four years and 1.7 billion miles, NASA’s revolutionary Dawn spacecraft thrusting via exotic ion propulsion is now less than 95,000 miles distant from Vesta, shaping its path through space to match the asteroid.
The internationally funded probe should be captured into orbit on July 16 at an initial altitude of 9,900 miles when Vesta is some 117 million miles from Earth.
After adjustments to lower Dawn to an initial reconnaissance orbit of approximately 1,700 miles, the science campaign is set to kick off in August with the collection of global color images and spectral data including compositional data in different wavelengths of reflected light.
Dawn Approaching Vesta
Dawn obtained this image on June 20, 2011. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/PSI and NASA/ESA/STScI/UMd
Dawn will spend a year investigating Vesta. It will probe the protoplanet using its three onboard science instruments – provided by Germany, Italy and the US – and provide researchers with the first bird’s eye images, global maps and detailed scientific measurements to elucidate the chemical composition and internal structure of a giant asteroid.
“Navigation images from Dawn’s framing camera have given us intriguing hints of Vesta, but we’re looking forward to the heart of Vesta operations, when we begin officially collecting science data,” said Christopher Russell, Dawn principal investigator, at the University of California, Los Angeles (UCLA). “We can’t wait for Dawn to peel back the layers of time and reveal the early history of our solar system.”
Because Dawn is now so close to Vesta, the frequency of imaging will be increased to twice a week to achieve the required navigational accuracy to successfully enter orbit., according to Marc Rayman, Dawn Chief Engineer at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif.
“By the beginning of August, it will see Vesta with more than 100 times the clarity that Hubble could ever obtain,” says Rayman.
Vesta in Spectrometer View
On June 8, 2011, the visible and infrared mapping spectrometer aboard NASA's Dawn spacecraft captured the instrument's first images of Vesta that are larger than a few pixels, from a distance of about 218,000 miles (351,000 kilometers). The image was taken for calibration purposes. An image obtained in the visible part of the light spectrum appears on the left. An image obtained in the infrared spectrum, at around 3 microns in wavelength, appears on the right. The spatial resolution of this image is about 60 miles (90 kilometers) per pixel. Credit: NASA/JPL-Caltech/UCLA/ASI/INAF
Dawn will gradually edge down closer to altitudes of 420 miles and 120 miles to obtain ever higher resolution orbital images and spectal data before spiraling back out and eventually setting sail for Ceres, the largest asteroid of them all.
Dawn will be the first spacecraft to orbit two celestial bodies, only made possible via the ion propulsion system. With a wingspan of 65 feet, it’s the largest planetary mission NASA has ever launched.
“We’ve packed our year at Vesta chock-full of science observations to help us unravel the mysteries of Vesta,” said Carol Raymond, Dawn’s deputy principal investigator at JPL.
“This is an unprecedented opportunity to spend a year at a body that we know almost nothing about,” added Raymond. “We are very interested in the south pole because the impact exposed the deep interior of Vesta. We’ll be able to look at features down to tens of meters so we can decipher the geologic history of Vesta.”
Possible Piece of Vesta
Scientists believe a large number of the meteorites that are found on Earth originate from the protoplanet Vesta. A cataclysmic impact at the south pole of Vesta, the second most massive object in the main asteroid belt, created an enormous crater and excavated a great deal of debris. Some of that debris ended up as other asteroids and some of it likely ended up on Earth. Image Credit: NASA/JPL-CaltechDawn Trajectory and Current Location on June 29, 2011. Credt: NASA/JPLDawn launch on September 27, 2007 by a Delta II rocket from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer
This is one of the Tagish Lake meteorite fragments. Credit: Michael Holly, Creative Services, University of Alberta
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We’re all familiar with the hypothesis of panspermia – that life can be “seeded” from the contents of asteroids, comets and planetoids vis-a-vis meteorite impacts – but so far no direct evidence has been found. So why should we even consider meteorites to be potential parents? The truth is out there – they contain the essentials – right down to amino acids. Up until now, what we’ve recovered has been considered structured. Then along came Tagish Lake…
In January, 2000, a large meteoroid exploded in Earth’s atmosphere over northern British Columbia, Canada, resulting in a debris fall over frozen Tagish Lake. It was a rare observed fall, and the meteorites were meticulously gathered, documented and preserved in their frozen state. The reason was twofold: to preserve the integrity of the space stones and to ensure no contamination could occur either to Earth or to the specimens.
“The Tagish Lake meteorite fell on a frozen lake in the middle of winter and was collected in a way to make it the best preserved meteorite in the world,” said Dr. Christopher Herd of the University of Alberta, Edmonton, Canada, lead author of a paper about the analysis of the meteorite fragments published June 10 in the journal Science.
For meteorite collectors, we’re well aware of the value of an observed fall and equally aware of the documentation needed to make a meteorite valuable both to market and scientific study. It’s more than just writing down the date and time of the observation and where the fragments were collected. To be done properly, the field needs to be measured. Each fragment needs to be photographed in the position in which it was found. The depth measured and more. Nothing is left to speculation.
“The first Tagish Lake samples – the ones we used in our study that were collected within days of the fall – are the closest we have to an asteroid sample return mission in terms of cleanliness,” adds Dr. Michael Callahan of NASA’s Goddard Space Flight Center in Greenbelt, Md., a co-author on the paper.
What the scientists found was the Tagish Lake meteorites are rich in carbon – and contain an assortment of organic matter including amino acids. While these “building blocks of life” aren’t new to meteoritic structure, what was out of the ordinary was different pieces had greatly differing amounts of amino acids. This varies way off the beaten path.
“We see that some pieces have 10 to 100 times the amount of specific amino acids than other pieces,” said Dr. Daniel Glavin of NASA Goddard, also a co-author on the Science paper. “We’ve never seen this kind of variability from a single parent asteroid before. Only one other meteorite fall, called Almahata Sitta, matches Tagish Lake in terms of diversity, but it came from an asteroid that appears to be a mash-up of many different asteroids.”
The team set to work on the recovered fragments – identifying different minerals present in each meteorite. What they were looking for was to see how much each had been changed by the presence of water. What they found was the different fragments each had a different water signature not accounted for from their landing on Earth. Some had more interaction and others less. This alteration may explain the diversity in amino acid production.
“Our research provides new insights into the role that water plays in the modification of pre-biotic molecules on asteroids,” said Herd. “Our results provide perhaps the first clear evidence that water percolating through the asteroid parent body caused some molecules to be formed and others destroyed. The Tagish Lake meteorite provides a unique window into what was happening to organic molecules on asteroids four-and-a-half billion years ago, and the pre-biotic chemistry involved.”
How does this change the way we look at the panspermia theory? If future falls continue to show this widespread variability, scientists are going to have to be a bit more reserved in their judgements about whether or not meteorites could deliver enough bio-molecules to make the hypothesis viable.
“Biochemical reactions are concentration dependent,” says Callahan. “If you’re below the limit, you’re toast, but if you’re above it, you’re OK. One meteorite might have levels below the limit, but the diversity in Tagish Lake shows that collecting just one fragment might not be enough to get the whole story.”
While the Tagish Lake samples are undoubtedly some of the most carefully preserved specimens collected so far, there is still a possibility of contamination from both Earth atmosphere and their lake landing. But don’t simply write off these new findings just yet. In one fragment, the amino acid abundances were high enough to show they were made in space by analyzing their isotopes. These versions of elements with different masses can tell us a lot more about the story. For example, the carbon 13 found in the Tagish Lake samples is a much heavier, and less common, variety of carbon. Because amino acids prefer lighter forms of carbon, the enriched and heavier carbon 13 deposits were most likely created in space.
“We found that the amino acids in a fragment of Tagish Lake were enriched in carbon 13, indicating they were probably created by non-biological processes in the parent asteroid,” said Dr. Jamie Elsila of NASA Goddard, a co-author on the paper who performed the isotopic analysis.
The team compared their results with researchers at the Goddard Astrobiology Analytical Lab for their expertise with the difficult analysis. “We specialize in extraterrestrial amino acid and organic matter analysis,” said Dr. Jason Dworkin, a co-author on the paper who leads the Goddard laboratory. “We have top-flight, extremely sensitive equipment and the meticulous techniques necessary to make such precise measurements. We plan to refine our techniques with additional challenging assignments so we can apply them to the OSIRIS-REx asteroid sample return mission.”
A bright field scanning transmission electron microscope (STEM) micrograph showing a Wassonite grain in dark contrast. Credit: NASA
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It’s a brand new mineral, and it’s from space. Researchers taking a new look at an old meteorite with a high-tech electron microscope have found a new mineral, now called Wassonite, in a space rock found in Anarctica back in 1969, the Yamato 691 enstatite chondrite. The meteorite likely originated from the Asteroid Belt between Mars and Jupiter and is about 4.5 billion years old.
“Wassonite is a mineral formed from only two elements, sulfur and titanium, yet it possesses a unique crystal structure that has not been previously observed in nature,” said Keiko Nakamura-Messenger, a NASA scientist who headed the research team.
Wassonite now joins the list of 4,500 official minerals, approved by the International Mineralogical Association. It was named after meteorite researcher John T. Wasson, from the University of California, Los Angeles (UCLA).
But there could be more unknown minerals inside the meteorite. The researchers found Wassonite surrounded by additional minerals that have not been seen before, and the team is continuing their investigations.
The amount of Wassonite in the rock is less than one-hundredth the width of a human hair or 50×450 nanometers wide. Without NASA’s transmission electron microscope, which is capable of isolating the Wassonite grains and determining their chemical composition and atomic structure, the mineral would have been impossible to see.
In 1969, members of the Japanese Antarctic Research Expedition discovered nine meteorites on the blue ice field of the Yamato Mountains in Antarctica. This was the first significant recovery of Antarctic meteorites and represented samples of several different types. As a result, the United States and Japan conducted systematic follow-up searches for meteorites in Antarctica that recovered more than 40,000 specimens, including extremely rare Martian and lunar meteorites.
“More secrets of the universe can be revealed from these specimens using 21st century nano-technology,” said Nakamura-Messenger.
“Meteorites, and the minerals within them, are windows to the formation of our solar system,” said Lindsay Keller, space scientist at NASA’s Johnson Space Center in Houston, who was the principal investigator of the microscope used to analyze the Wassonite crystals. “Through these kinds of studies we can learn about the conditions that existed and the processes that were occurring then.”
For more information see this NASA pdf. which provides more images and details about the Wassonite detection.
Image of permineralized remains in the one of the meteorites studied by Richard Hoover. Credit: Journal of Cosmology
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A recent paper published by a NASA scientist claims the discovery evidence of fossil bacteria in a rare subclass of carbonaceous meteorite. The claims are extraordinary, and were the paper published somewhere other than the Journal of Cosmology, (and given an “exclusive preview” on Fox News) more people might be taking this seriously. But, even so, the topic went viral over the weekend.
Titled “Fossils of Cyanobacteria in CI1 Carbonaceous Meteorites” and written by NASA scientist Dr. Richard Hoover of the Marshall Space Flight Center, the paper makes the bold claim that meteorites found in France and Tanzania in the 1800s (the Alais, Ivuna, and Orgueil CI1 meteorites) have clear evidence pointing to space-dwelling microbes, with inferences of panspermia — the theory that microbes brought to Earth in comets and meteorites could have started life on our planet. “The implications,” says an online synopsis of the paper, “are that life is everywhere, and that life on Earth may have come from other planets.”
The paper states: “Filaments found in the CI1 meteorites have also been detected that exhibit structures consistent with the specialized cells and structures used by cyanobacteria for reproduction (baeocytes, akinetes and hormogonia), nitrogen fixation (basal, intercalary or apical heterocysts) and attachment or motility (fimbriae).”
Dr. Chris McKay, a planetary scientist and astrobiologist at NASA Ames Research Center, pointed out to Universe Today that Hoover’s claims are “extraordinary, because of the ecological setting implied. Cyanobacteria live in liquid water and are photosynthetic.”
McKay said finding heterocysts (cells formed by some filamentous cyanobacteria) would certainly be indicative of life from an actively thriving environment. “The implication of these results is that the meteorite hosted a liquid water environment in contact with sunlight and high oxygen,” he told Universe Today in an email.
Image at 1000 X of multiple filaments and sheaths embedded in Orgueil meteorite. Credit: Journal of Cosmology
There have been previous reports of bacteria in meteorites, but most have turned out to be contamination or misunderstanding of the microscopic structures within rocks (remember the Alan Hills Meteorite claim from 1996 –which is still widely controversial.) It turns out that Dr. Hoover has reported fossil bacteria previously, but none have actually been proven. And, it also turns out that Hoover’s paper was submitted to the Astrobiology Journal in 2007, but the review was never completed.
“Richard Hoover is a careful and accomplished microscopist so there is every reason to believe that the structures he sees are present and are not due to contamination,” McKay said. “If these structures had been reported from sediments from a lake bottom there would be no question that they were classified correctly as biological remains.”
There are two possibilities, McKay said. “One, the structures are not biological but are chance shapes. In a millimeter square area of meteorite there are million possible 1 micron squares. Perhaps any diversity of shapes can be found if searching is extensive.”
Or the second possibility, McKay said is that “the environments on meteorites are, or were, radically different from what we would expect. There are suggestions for how meteorite parent bodies could have sustained interior liquid water. But not in a way that could have the liquid water exposed to sunlight. It also seems unlikely that high oxygen concentrations would be implied.”
There’s also the question of why Hoover would choose to publish in the somewhat dubious Journal of Cosmology, an open access, but supposedly peer-reviewed online journal, which has come under fire for errors found in some of their articles, and for the rather sensational claims made by some of the papers published within.
But word also was released by the Journal of Cosmology that they will cease publication in May 2011. In a press release titled, “Journal of Cosmology To Stop Publishing–Killed by Thieves and Crooks,” (posted by journalist David Dobbs), the press release said that the “JOC threatened the status quo at NASA,” and that “JOC’s success posed a direct threat to traditional subscription based science periodicals, such as “science” magazine; just as online news killed many newspapers. Not surprisingly, JOC was targeted by science magazine and others who engaged in illegal, criminal, anti-competitive acts to prevent JOC from distributing news about its online editions and books.”
UPDATE: NASA has released a statement on Hoover’s paper, saying that “NASA cannot stand behind or support a scientific claim unless it has been peer-reviewed or thoroughly examined by other qualified experts. This paper was submitted in 2007 to the International Journal of Astrobiology. However, the peer review process was not completed for that submission. NASA also was unaware of the recent submission of the paper to the Journal of Cosmology or of the paper’s subsequent publication. Additional questions should be directed to the author of the paper.” – Dr. Paul Hertz, chief scientist of NASA’s Science Mission Directorate in Washington
But Hoover’s work is generating a huge buzz.
The journal’s editor in chief, Rudy Schild of the Harvard-Smithsonian Centre for Astrophysics, said Hoover is a “highly respected scientist and astrobiologist with a prestigious record of accomplishment at NASA. Given the controversial nature of his discovery, we have invited 100 experts and have issued a general invitation to over 5,000 scientists from the scientific community to review the paper and to offer their critical analysis.”
“No other paper in the history of science has undergone such a thorough analysis, and no other scientific journal in the history of science has made such a profoundly important paper available to the scientific community, for comment, before it is published,” Schild added. Those commentaries will be published March 7 through March 10, and can be found here.
Certainly, further review of Hoover’s work needs to be conducted.
False-color compositional x-ray image of the rim and margin of a ~4.6 billion-year-old calcium aluminum refractory inclusion (CAI) from the Allende carbonaceous chondrite. Credit: Erick Ramon and Justin Simon
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Feast your eyes on some of the solar system’s earliest materials: the pink core comprises melilite, spinel and perovskite. The multi-colored rim contains hibonite, perovskite, spinel, melilite/sodalite, pyroxene, and olivine. This close-up reveals part of a pea-sized chunk of meteorite, a calcium-aluminum rich inclusion, formed when the planets in our solar system were still dust grains swirling around the sun — and it can tell an early part of the story about what happened next.
Pieces of the Allende meteorite, the largest carbonaceous chondrite ever found on Earth. Estimated to have been the size of a car, it broke up as it fell through the atmosphere in 1969, showering the ground in Chichuahua, Mexico, with hundreds of pieces, many collected for subsequent study. Credit: NASA
Meteorites have puzzled space scientists for more than 100 years because they contain minerals that could only form in cold environments, as well as minerals that have been altered by hot environments. Carbonaceous chondrites, in particular, contain millimeter-sized chondrules and up to centimeter-sized calcium-aluminum-rich inclusions, like the one shown above, that were once heated to the melting point and later welded together with cold space dust.
“These primitive meteorites are like time capsules, containing the most primitive materials in our solar system,” said Justin Simon, an astromaterials researcher at NASA’s Johnson Space Center in Houston, who led the new study. “CAIs are some of the most interesting meteorite components. They recorded the history of the solar system before any of the planets formed, and were the first solids to condense out of the gaseous nebula surrounding our protosun.”
For the new paper, which appears in Science today, Simon and his colleagues performed a micro-probe analysis to measure oxygen isotope variations in micrometer-scale layers of the core and outer layers of the ancient grain, estimated to be 4.57 billion years old.
All of these calcium-aluminum-rich inclusions, or CAIs, are thought to have originated near the protosun, which enriched the nebular gas with the isotope oxygen-16. In the inclusion analyzed for the new study, the abundance of oxygen-16 was found to decrease outward from the center of the core, suggesting that it formed in the inner solar system, where oxygen-16 was more abundant, but later moved farther from the sun and lost oxygen-16 to the surrounding 16O-poor gas.
Credit: Justin Simon/NASA
Simon and his colleagues propose that initial rim formation could have occurred as inclusions fell back into the midplane of the disk, indicated by the dashed path A above; as they migrated outward within the plane of the disk, shown as path B; and/ or as they entered high density waves (i.e., shockwaves). Shockwaves would be a reasonable source for the implied 16O-poor gas, increased dust abundance and thermal heating. The first mineral layer outside the core had more oxygen-16, implying that the grain had subsequently returned to the inner solar system. Outer rim layers had varying isotope compositions, but in general indicate that they also formed closer to the sun, and/or in regions where they had lower exposure to the 16O-poor gas from which the terrestrial planets formed.
The researchers interpret these findings as evidence that dust grains traveled over large distances as the swirling protoplanetary nebula condensed into planets. The single dust grain they studied appears to have formed in the hot environment of the sun, may have been thrown out of the plane of the solar system to fall back into the asteroid belt, and eventually recirculated back to the sun.
This odyssey is consistent with some theories about how dust grains formed in the early protoplanetary nebula, or propylid, eventually seeding the formation of planets.
Perhaps the most popular theory explaining the composition of chrondrules and CAIs is the so-called X-wind theory propounded by former UC Berkeley astronomer Frank Shu. Shu depicted the early protoplanetary disk as a washing machine, with the sun’s powerful magnetic fields churning the gas and dust and tossing dust grains formed near the sun out of the disk.
Once expelled from the disk, the grains were pushed outward to fall like rain into the outer solar system. These grains, both flash-heated chondrules and slowly heated CAIs, were eventually incorporated along with unheated dust into asteroids and planets.
“There are problems with the details of this model, but it is a useful framework for trying to understand how material originally formed near the sun can end up out in the asteroid belt,” said coauthor Ian Hutcheon, deputy director of Lawrence Livermore National Laboratory’s Glenn T. Seaborg Institute.
In terms of today’s planets, the grain probably formed within the orbit of Mercury, moved outward through the region of planet formation to the asteroid belt between Mars and Jupiter, and then traveled back toward the sun again.
“It may have followed a trajectory similar to that suggested in the X-wind model,” Hutcheon said. “Though after the dust grain went out to the asteroid belt or beyond, it had to find its way back in. That’s something the X-wind model doesn’t talk about at all.”
Simon plans to crack open and probe other CAIs to determine whether this particular CAI (referred to as A37) is unique or typical.
Source: Science and a press release from the University of California at Berkeley.
How often have you seen a meteor streak across the sky and wondered where it came from and what it was? A new network of smart cameras that NASA is setting up will hopefully help answer those questions for as many fireballs as possible, at least in the US.
“If someone calls me and asks ‘What was that?’ I’ll be able to tell them,” said William Cooke, head of NASA’s Meteoroid Environment Office. With the new camera network, Cooke and his team hope to have a record of every big meteoroid that enters the atmosphere over the certain parts of the U.S. “Nothing will burn up in those skies without me knowing about it!” he added.
And the exciting part is that Cooke is looking to partner with schools, science centers, and planetaria willing to host his cameras.
It is estimated that every day about 100 tons of meteoroids — fragments of dust and gravel and sometimes even big rocks – enter the Earth’s atmosphere. But surprisingly, not much is known about the origin of all this stuff.
Groups of these smart cameras in the new meteor network will be able to automatically triangulate the fireballs’ paths, and special software will be able to compute their orbits.
In other U.S. meteor networks, someone has to manually look at all the cameras’ data and calculate the orbits – a painstaking process.
“With our network, our computers do it for us – and fast,” said Cooke.
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The network’s first three cameras, each about the size of a gumball machine, are already up and running. Cooke’s team will soon have 15 cameras deployed east of the Mississippi River, with plans to expand nationwide.
How can you get involved? Here is the criteria for the locations Cooke is currently looking for:
1. Location east of the Mississippi River
2. Clear horizon (few trees)
3. Few bright lights (none close to camera)
4. Fast internet connection
The smart meteor network uses ASGARD (All Sky and Guided Automatic Realtime Detection) software, developed at the University of Western Ontario, which hosts the Southern Ontario Meteor Network, which took the video at the top of this article. The software processes the visual information and performs the triangulation needed to determine the orbits and origins of the fireballs.
The cameras can also provide information on where any potential meteorites may have landed, which is great for meteorite hunters and scientists. Getting a piece of a space rock is like a free sample return mission.
NASA's Smart Meteor Network is catching more than fireballs. Click on the image to see a movie where a bird stops to rest on one of the cameras in Georgia.
All cameras in the network send their fireball information to Cooke and to a public website. Teachers can contact Cooke at [email protected] to request teacher workshop slides containing suggestions for classroom use of the data. Students can learn to plot fireball orbits and speeds, where the objects hit the ground, how high in the atmosphere the fireballs burn up, etc.
But anyone can try meteor watching on their own, without being part of the network.
“Go out on a clear night, lie flat on your back, and look straight up,” Cooke said. “It will take 30 to 40 minutes for your eyes to become light adapted, so be patient. By looking straight up, you may catch meteor streaks with your peripheral vision too. You don’t need any special equipment — just your eyes.”
Then – if you are lucky to see some bright fireballs — you can check the fireball website to find out more information about what you saw.
Researchers have teased ammonia of a carbon-containing meteorite from Antarctica, and propose that meteorites may have delivered that essential ingredient for life to an early Earth.
The results appear today in the Proceedings of the National Academy of Sciences, and add to a growing body of evidence that meteorites may have played a key role in the development of life here. The NASA graphic at left was released just last month, when researchers reported that meteorites may have also delivered Earth’s first left-hand amino acids.
A Renazzo stony meteorite. Credit: NASA
Lead author Sandra Pizzarello, of Arizona State University, and her colleagues note in the new paper that carbonaceous chondrites are asteroidal meteorites known to contain abundant organic materials.
“Given that meteorites and comets have reached the Earth since it formed, it has been proposed that the exogenous influx from these bodies provided the organic inventories necessary for the emergence of life,” they write.
The carbonaceous meteorites of the Renazzo-type family (CR) are known to be especially rich in small soluble organic molecules, such as the amino acids glycine and alanine. To test for the presence of ammonia, the researchers collected powder from the much-studied CR2 Grave Nunataks (GRA) 95229 meteorite and treated it with water at high temperature and pressure. They found that the treated powders emitted ammonia, NH4, an important precursor to complex biological molecules such as amino acids and DNA, into the surrounding water.
Next, the researchers analyzed the nitrogen atoms within the ammonia and determined that the atomic isotope did not match those currently found on Earth, eliminating the possibility that the ammonia resulted from contamination during the experiment. Researchers have struggled to pinpoint the origin of the ammonia responsible for triggering the formation of the first biomolecules on early Earth. The authors suggest that now, they may have found it.
“The findings appear to trace CR2 meteorites’ origin to cosmochemical regimes where ammonia was pervasive, and we speculate that their delivery to the early Earth could have fostered prebiotic molecular evolution,” they write.
It’s generally assumed that the Earth’s overall composition is similar to that of chondritic meteorites, the primitive, undifferentiated building blocks of the solar system. But a new study in Science Express led by Frederic Moynier, of the University of California at Davis, seems to suggest that Earth is a bit of an oddball.
Thin section of a chondritic meteorite. Credit: NASA
Moynier and his colleagues analyzed the isotope signature of chromium in a variety of meteorites, and found that it differed from chromium’s signature in the mantle.
“We show through high-precision measurements of Cr stable isotopes in a range of meteorites, which deviate by up to ~0.4‰ from the bulk silicate Earth, that Cr depletion resulted from its partitioning into Earth’s core with a preferential enrichment in light isotopes,” the authors write. “Ab-initio calculations suggest that the isotopic signature was established at mid-mantle magma ocean depth as Earth accreted planetary embryos and progressively became more oxidized.”
Chromium’s origins. New evidence suggests that, in the early solar nebula (A), chromium isotopes were divided into two components, one containing light isotopes, the other heavy isotopes. In the early Earth (B), these components formed a homogeneous mixture. During core partitioning (C), the core became enriched with lighter chromium isotopes, and the mantle with heavier isotopes. Courtesy of Science/AAAS
The results point to a process known as “core partitioning,” rather than an alternative process involving the volatilization of certain chromium isotopes so that they would have escaped from the Earth’s mantle. Core partitioning took place early on Earth at high temperatures, when the core separated from the silicate earth, leaving the core with a distinct composition that is enriched with lighter chromium isotopes, notes William McDonough, from the University of Maryland at College Park, in an accompanying Perspective piece.
McDonough writes that chromium, Earth’s 10th most abundant element, is named for the Greek word for color and “adds green to emeralds, red to rubies, brilliance to plated metals, and corrosion-proof quality to stainless steels.” It is distributed roughly equally throughout the planet.
He says the new result “adds another investigative tool for understanding and documenting past and present planetary processes. For the cosmochemistry and meteoritics communities, the findings further bolster the view that the solar nebula was a heterogeneous mixture of different components.”
Source: Science. The McDonough paper will be published online today by the journal Science, at the Science Express website.
