четверг, 14 февраля 2019 г.

2400 Year Old Kingsteignton Oak Figure, Royal Albert Memorial Museum, Exeter.




2400 Year Old Kingsteignton Oak Figure, Royal Albert Memorial Museum, Exeter.


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Iron Age Chariot Linchpin and Replica, Royal Albert Memorial Museum, Exeter. Linchpins...


Iron Age Chariot Linchpin and Replica, Royal Albert Memorial Museum, Exeter.


Linchpins pass through a chariot axle to keep the wheels on.


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Wired for Weight While it may be tempting to blame your…


Wired for Weight


While it may be tempting to blame your rumbling tummy for feelings of hunger, it’s actually the brain the controls food intake – specifically a region known as the hypothalamus, a small clump of nerve cells buried deep in the centre of the brain. Using zebrafish as a convenient laboratory model for human brains, researchers are figuring out how the wiring in the hypothalamus controls bodyweight. This image shows the hypothalamus from a zebrafish, which has been stained to show the circuit of nerve cells that control body weight (red and green), revealing bright pathways of connections and dark regions that the nerve cells avoid. These connections are controlled by molecules known as semaphorins, which act as a ‘road map’ for the brain. Interfering with semaphorins leads to increased body weight, and alterations in sempahorin genes are found in some overweight humans, confirming this important link between brain wiring and bodyweight.


Written by Kat Arney



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2019 February 14 Solar System Family Portait Image Credit:…


2019 February 14


Solar System Family Portait
Image Credit: Voyager Project, NASA


Explanation: On Valentine’s Day in 1990, cruising four billion miles from the Sun, the Voyager 1 spacecraft looked back one last time to make this first ever Solar System family portrait. The complete portrait is a 60 frame mosaic made from a vantage point 32 degrees above the ecliptic plane. In it, Voyager’s wide angle camera frames sweep through the inner Solar System at the left, linking up with gas giant Neptune, the Solar System’s outermost planet, at the far right. Positions for Venus, Earth, Jupiter, Saturn, Uranus, and Neptune are indicated by letters, while the Sun is the bright spot near the center of the circle of frames. The inset frames for each of the planets are from Voyager’s narrow field camera. Unseen in the portrait are Mercury, too close to the Sun to be detected, and Mars, unfortunately hidden by sunlight scattered in the camera’s optical system. Closer to the Sun than Neptune at the time, small, faint Pluto’s position was not covered.


∞ Source: apod.nasa.gov/apod/ap190214.html


Safe havens for young planets



Credit: ALMA (ESO/NAOJ/NRAO), S. Andrews et al.; NRAO/AUI/NSF, S. Dagnello



This week’s Picture of the Week focuses on one of twenty protoplanetary discs explored and imaged by ALMA’s first Large Program, known as the Disk Substructures at High Angular Resolution Project (DSHARP). The disc is called AS 209, and its substructures are particularly pronounced thanks to its thin, high-contrast rings and almost face-on orientation towards us.


Though concentric rings — shown here in particularly beautiful clarity — are a common substructure among such discs, their widths, separations, and number can vary greatly. It’s still unclear how these substructures form, and how planets emerge from them. Quantifying and studying these similarities and differences was a motivator for constructing ALMA, and was the main objective of DSHARP. These details may hold clues to the type of planetary system that will eventually emerge.


One interpretation is that there may be a rapid and complex interplay between young protoplanets and the disc itself far earlier in the evolution of the planetary system than previously thought. A leading theory of planet formation requires dust within these discs to clump into grains, then pebbles, and eventually planetesimals. This theory has always been stumped, however, by the fact that once an object reaches a certain mass, the dynamics of these discs would cause it to be sucked into the host star at the centre, thus halting its growth into a true planet. The results from the DSHARP program suggest that disc substructures may perturb these dynamics and provide safe havens where young planetesimals can continue growing — making the substructures observed here crucial to our own existence.


Next week’s picture will be the final instalment in the DSHARP series, and will showcase another of the twenty images: this time a multiple star system.


Source: ESO/Potw



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Worlds with many suns


Credit: ALMA (ESO/NAOJ/NRAO), S. Andrews et al.; NRAO/AUI/NSF, S. Dagnello


This week’s Picture of the Week highlights another of the 20 images to come out of ALMA’s first Large Program, the Disk Substructures at High Angular Resolution Project (DSHARP). DSHARP explored a number of nearby protoplanetary discs to learn more about the earliest stages of planet formation, and a staggering quantity of data from the project has just been released.


This object, called AS 205, is notable for being a multiple star system, one of two such systems imaged by DSHARP (the other being HT Lup). While two discs are discernible here, the lower right disc is in fact shared by two stars in a binary system, so we are actually looking at a system of three fledgling stars.


Although most high-resolution studies have so far focused on single stars, multiple systems are far from uncommon in the Universe. It is thought that over half of all stars may exist in multiple systems, an estimate that may be even higher for young stars. The presence of companion stars is likely to have complex implications for a disc and its substructures. This is due to as the gravitational influence of a stellar neighbour, which may distort and redistribute the material within the disc. Data from AS 205 and HT Lup indicate that stars and their neighbouring discs interact strongly.


Despite their unsettled birth environments, planets have been detected in multiple stellar systems — some orbiting just one of the stars, others orbiting the entire system. The latter are more likely to have stable orbits than the former, which get caught up in volatile interstellar dynamics.



Source: ESO/Potw



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Ancient Caucasus open analysis and discussion

The following samples from the recent Wang et al. paper on the genetic prehistory of the Caucasus are now in the Global25 datasheets:



Catacomb RK4001
Catacomb RK4002
Darkveti-Meshoko I2056
Kura-Araxes_Kaps ARM001
Kura-Araxes_Kaps ARM002-003
Kura-Araxes_Velikent VEK007-009
Maykop_Late MK5004
Maykop_Late SIJ003
Maykop_Novosvobodnaya I6266
Maykop_Novosvobodnaya I6272
North_Caucasus_MBA KDC001
North_Caucasus_MBA KDC002
Progress_Eneolithic PG2001
Progress_Eneolithic PG2004
Steppe_Maykop AY2001
Steppe_Maykop AY2003
Steppe_Maykop SA6001
Steppe_Maykop SA6004
Steppe_Maykop_o SA6013
Vonyuchka_Eneolithic VJ1001
Yamnaya_Caucasus RK1001
Yamnaya_Caucasus ZO2002



A lot of people don’t seem to be aware of this, but the links are always the same for all of the datasheets, even after major updates:



Global 25 datasheet (scaled)
Global 25 pop averages (scaled)
Global 25 datasheet
Global 25 pop averages



Feel free to analyze the data in any way you wish and share your findings in the comments. Did the authors miss anything?
See also…
Big deal of 2018: Yamnaya not related to Maykop

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NASA’s Record-Setting Opportunity Rover Mission on Mars Comes to End


NASA – Mars Exploration Rover B (MER-B) patch.


Feb. 13, 2019


One of the most successful and enduring feats of interplanetary exploration, NASA’s Opportunity rover mission is at an end after almost 15 years exploring the surface of Mars and helping lay the groundwork for NASA’s return to the Red Planet.


The Opportunity rover stopped communicating with Earth when a severe Mars-wide dust storm blanketed its location in June 2018. After more than a thousand commands to restore contact, engineers in the Space Flight Operations Facility at NASA’s Jet Propulsion Laboratory (JPL) made their last attempt to revive Opportunity Tuesday, to no avail. The solar-powered rover’s final communication was received June 10.


“It is because of trailblazing missions such as Opportunity that there will come a day when our brave astronauts walk on the surface of Mars,” said NASA Administrator Jim Bridenstine. “And when that day arrives, some portion of that first footprint will be owned by the men and women of Opportunity, and a little rover that defied the odds and did so much in the name of exploration.”



Animation above: Side-by-side movies shows how dust has enveloped the Red Planet, courtesy of the Mars Color Imager (MARCI) wide-angle camera onboard NASA’s Mars Reconnaissance Orbiter (MRO). Animation Credits: NASA/JPL-Caltech/MSSS.


Designed to last just 90 Martian days and travel 1,100 yards (1,000 meters), Opportunity vastly surpassed all expectations in its endurance, scientific value and longevity. In addition to exceeding its life expectancy by 60 times, the rover traveled more than 28 miles (45 kilometers) by the time it reached its most appropriate final resting spot on Mars – Perseverance Valley.


“For more than a decade, Opportunity has been an icon in the field of planetary exploration, teaching us about Mars’ ancient past as a wet, potentially habitable planet, and revealing uncharted Martian landscapes,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate. “Whatever loss we feel now must be tempered with the knowledge that the legacy of Opportunity continues – both on the surface of Mars with the Curiosity rover and InSight lander – and in the clean rooms of JPL, where the upcoming Mars 2020 rover is taking shape.”



Image above: The dramatic image of NASA’s Mars Exploration Rover Opportunity’s shadow was taken on sol 180 (July 26, 2004) by the rover’s front hazard-avoidance camera as the rover moved farther into Endurance Crater in the Meridiani Planum region of Mars. Image Credits: NASA/JPL-Caltech.


The final transmission, sent via the 70-meter Mars Station antenna at NASA’s Goldstone Deep Space Complex in California, ended a multifaceted, eight-month recovery strategy in an attempt to compel the rover to communicate.


“We have made every reasonable engineering effort to try to recover Opportunity and have determined that the likelihood of receiving a signal is far too low to continue recovery efforts,” said John Callas, manager of the Mars Exploration Rover (MER) project at JPL.


Opportunity landed in the Meridiani Planum region of Mars on Jan. 24, 2004, seven months after its launch from Cape Canaveral Air Force Station in Florida. Its twin rover, Spirit, landed 20 days earlier in the 103-mile-wide (166-kilometer-wide) Gusev Crater on the other side of Mars. Spirit logged almost 5 miles (8 kilometers) before its mission wrapped up in May 2011.



Mars Exploration Rover (MER): Image Credits: NASA/JPL-Caltech

From the day Opportunity landed, a team of mission engineers, rover drivers and scientists on Earth collaborated to overcome challenges and get the rover from one geologic site on Mars to the next. They plotted workable avenues over rugged terrain so that the 384-pound (174-kilogram) Martian explorer could maneuver around and, at times, over rocks and boulders, climb gravel-strewn slopes as steep as 32-degrees (an off-Earth record), probe crater floors, summit hills and traverse possible dry riverbeds. Its final venture brought it to the western limb of Perseverance Valley.


“I cannot think of a more appropriate place for Opportunity to endure on the surface of Mars than one called Perseverance Valley,” said Michael Watkins, director of JPL. “The records, discoveries and sheer tenacity of this intrepid little rover is testament to the ingenuity, dedication, and perseverance of the people who built and guided her.”



Opportunity: NASA Rover Completes Mars Mission

Video above: Drive along with the NASA’s Opportunity Mars rover and hear the voices of scientists and engineers behind the mission. Designed to run for 90 days, the exploration spanned more than 15 years from 2004 to 2019. Along the way, it discovered definitive proof of liquid water on ancient Mars and set the off-world driving record. For more information on the Mars Exploration Rovers and all of NASA’s Mars missions, visit mars.nasa.gov. Video Credits: NASA/JPL-Caltech.


More Opportunity Achievements


– Set a one-day Mars driving record March 20, 2005, when it traveled 721 feet (220 meters).


– Returned more than 217,000 images, including 15 360-degree color panoramas.


– Exposed the surfaces of 52 rocks to reveal fresh mineral surfaces for analysis and cleared 72 additional targets with a brush to prepare them for inspection with spectrometers and a microscopic imager.


– Found hematite, a mineral that forms in water, at its landing site.


– Discovered strong indications at Endeavour Crater of the action of ancient water similar to the drinkable water of a pond or lake on Earth.


All of the off-roading and on-location scientific analyses were in service of the Mars Exploration Rovers’ primary objective: To seek out historical evidence of the Red Planet’s climate and water at sites where conditions may once have been favorable for life. Because liquid water is required for life, as we know it, Opportunity’s discoveries implied that conditions at Meridiani Planum may have been habitable for some period of time in Martian history.


“From the get-go, Opportunity delivered on our search for evidence regarding water,” said Steve Squyres, principal investigator of the rovers’ science payload at Cornell University. “And when you combine the discoveries of Opportunity and Spirit, they showed us that ancient Mars was a very different place from Mars today, which is a cold, dry, desolate world. But if you look to its ancient past, you find compelling evidence for liquid water below the surface and liquid water at the surface.”


All those accomplishments were not without the occasional extraterrestrial impediment. In 2005 alone, Opportunity lost steering to one of its front wheels, a stuck heater threatened to severely limit the rover’s available power, and a Martian sand ripple almost trapped it for good. Two years later, a two-month dust storm imperiled the rover before relenting. In 2015, Opportunity lost use of its 256-megabyte flash memory and, in 2017, it lost steering to its other front wheel.



Opportunity wheel traces : Image Credit: NASA.

Each time the rover faced an obstacle, Opportunity’s team on Earth found and implemented a solution that enabled the rover to bounce back. However, the massive dust storm that took shape in the summer of 2018 proved too much for history’s most senior Mars explorer.


“When I think of Opportunity, I will recall that place on Mars where our intrepid rover far exceeded everyone’s expectations,” Callas said. “But what I suppose I’ll cherish most is the impact Opportunity had on us here on Earth. It’s the accomplished exploration and phenomenal discoveries. It’s the generation of young scientists and engineers who became space explorers with this mission. It’s the public that followed along with our every step. And it’s the technical legacy of the Mars Exploration Rovers, which is carried aboard Curiosity and the upcoming Mars 2020 mission. Farewell, Opportunity, and well done.”


Mars exploration continues unabated. NASA’s InSight lander, which touched down on Nov. 26, is just beginning its scientific investigations. The Curiosity rover has been exploring Gale Crater for more than six years. And, NASA’s Mars 2020 rover and the European Space Agency’s ExoMars rover both will launch in July 2020, becoming the first rover missions designed to seek signs of past microbial life on the Red Planet.


Related articles:


Opportunity Hunkers Down During Dust Storm
https://orbiterchspacenews.blogspot.com/2018/06/opportunity-hunkers-down-during-dust.html


Shades of Martian Darkness
https://orbiterchspacenews.blogspot.com/2018/06/shades-of-martian-darkness.html


Update on Opportunity Rover after Martian Dust Storm
https://orbiterchspacenews.blogspot.com/2018/10/update-on-opportunity-rover-after.html


NASA Encounters the Perfect Storm for Science
https://orbiterchspacenews.blogspot.com/2018/06/nasa-encounters-perfect-storm-for.html


JPL managed the Mars Exploration Rovers Opportunity and Spirit for NASA’s Science Mission Directorate in Washington. For more information about the agency’s Mars Exploration program, visit: https://www.nasa.gov/mars


Mars Exploration Rovers (Spirit and Opportunity): https://www.nasa.gov/mission_pages/mer/index.html


Images (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/Dwayne Brown/JoAnna Wendel/Karen Northon/JPL/DC Agle.


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NASA Selects New Mission to Explore Origins of Universe


NASA logo.


Feb. 13, 2019


NASA has selected a new space mission that will help astronomers understand both how our universe evolved and how common are the ingredients for life in our galaxy’s planetary systems.



Image above: NASA’s Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer (SPHEREx) mission is targeted to launch in 2023. SPHEREx will help astronomers understand both how our universe evolved and how common are the ingredients for life in our galaxy’s planetary systems. Image Credits: Caltech.


The Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer (SPHEREx) mission is a planned two-year mission funded at $242 million (not including launch costs) and targeted to launch in 2023.


“I’m really excited about this new mission,” said NASA Administrator Jim Bridenstine. “Not only does it expand the United States’ powerful fleet of space-based missions dedicated to uncovering the mysteries of the universe, it is a critical part of a balanced science program that includes missions of various sizes.”


SPHEREx will survey the sky in optical as well as near-infrared light which, though not visible to the human eye, serves as a powerful tool for answering cosmic questions. Astronomers will use the mission to gather data on more than 300 million galaxies, as well as more than 100 million stars in our own Milky Way.


“This amazing mission will be a treasure trove of unique data for astronomers,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate. “It will deliver an unprecedented galactic map containing ‘fingerprints’ from the first moments in the universe’s history. And we’ll have new clues to one of the greatest mysteries in science: What made the universe expand so quickly less than a nanosecond after the big bang?”


SPHEREx will survey hundreds of millions of galaxies near and far, some so distant their light has taken 10 billion years to reach Earth. In the Milky Way, the mission will search for water and organic molecules – essentials for life, as we know it – in stellar nurseries, regions where stars are born from gas and dust, as well as disks around stars where new planets could be forming.


Every six months, SPHEREx will survey the entire sky using technologies adapted from Earth satellites and Mars spacecraft. The mission will create a map of the entire sky in 96 different color bands, far exceeding the color resolution of previous all-sky maps. It also will identify targets for more detailed study by future missions, such as NASA’s James Webb Space Telescope and Wide Field Infrared Survey Telescope.


NASA’s Astrophysics Explorers Program requested proposals for new missions in September 2016. Nine proposals were submitted, and two mission concepts were selected for further study in August 2017. After a detailed review by a panel of NASA and external scientists and engineers, NASA determined that the SPHEREx concept study offered the best science potential and most feasible development plan.


The mission’s principal investigator is James Bock of the California Institute of Technology (Caltech) in Pasadena, California. Caltech will work with NASA’s Jet Propulsion Laboratory (JPL) to develop the mission payload. JPL will also manage the mission.


Ball Aerospace in Broomfield, Colorado, will provide the SPHEREx spacecraft and mission integration. The Korea Astronomy & Space Science Institute in Daejeon, Republic of Korea, will contribute test equipment and science analysis.


NASA’s Explorer program, managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, is the agency’s oldest continuous program, designed to provide frequent, low-cost access to space using principal investigator-led space science investigations relevant to the Astrophysics and Heliophysics programs in NASA’s Science Mission Directorate.


The program has launched more than 90 missions, beginning in 1958 with Explorer 1, which discovered the Earth’s radiation belts. Another Explorer mission, the Cosmic Background Explorer, which launched in 1989, led to a Nobel Prize.


More information about the Explorer program is available online at: https://explorers.gsfc.nasa.gov


Image (mentioned), Text, Credits: NASA/Steve Cole/Karen Northon.


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The Opportunity to Rove on Mars! 🔴

Today, we’re expressing gratitude for the opportunity to rove on Mars (#ThanksOppy) as we mark the completion of a

successful mission that exceeded our expectations.  


Our Opportunity Rover’s last communication with Earth was received on June 10, 2018, as a planet-wide dust storm blanketed the solar-powered rover’s location on the western rim of Perseverance Valley, eventually blocking out so much sunlight that the rover could no longer charge its batteries. Although the skies over Perseverance cleared, the rover did not respond to a final communication attempt on Feb. 12, 2019.


As the rover’s mission comes to an end, here are a few things to know about its opportunity to explore the Red Planet.


90 days turned into 15 years!



Opportunity launched on July 7, 2003 and landed on Mars on Jan. 24, 2004 for a planned mission of 90 Martian days, which is equivalent to 92.4 Earth days. While we did not expect the golf-cart-sized rover to survive through a Martian winter, Opportunity defied all odds as a 90-day mission turned into 15 years!


image



The Opportunity caught its own silhouette in this late-afternoon image taken in March 2014 by the rover’s rear hazard avoidance camera. This camera is mounted low on the rover and has a wide-angle lens.





Opportunity Set  Out-Of-This-World Records


Opportunity’s achievements, including confirmation water once flowed on Mars. Opportunity was, by far, the longest-lasting lander on Mars. Besides endurance, the six-wheeled rover set a roaming record of 28 miles.


image


This chart illustrates comparisons among the distances driven by various wheeled vehicles on the surface of Earth’s moon and Mars. Opportunity holds the off-Earth roving distance record after accruing 28.06 miles (45.16 kilometers) of driving on Mars.



It’s Just Like Having a Geologist on Mars



Opportunity was created to be the mechanical equivalent of a geologist walking from place to place on the Red Planet. Its mast-mounted cameras are 5 feet high and provided 360-degree two-eyed, human-like views of the terrain. The robotic arm moved like a human arm with an elbow and wrist, and can place instruments directly up against rock and soil targets of interest. The mechanical “hand” of the arm holds a microscopic camera that served the same purpose as a geologist’s handheld magnifying lens.


image

There’s Lots to See on Mars



After an airbag-protected landing craft settled onto the Red Planet’s surface and opened, Opportunity rolled out to take panoramic images. These images gave scientists the information they need to select promising geological targets that tell part of the story of water in Mars’ past. Since landing in 2004, Opportunity has captured more than 200,000 images. Take a look in this photo gallery.


image



From its perch high on a ridge, the Opportunity rover recorded this image on March 31, 2016 of a Martian dust devil twisting through the valley below. The view looks back at the rover’s tracks leading up the north-facing slope of “Knudsen Ridge,” which forms part of the southern edge of “Marathon Valley




There Was Once Water on Mars?!


Among the mission’s scientific goals was to search for and characterize a wide range of rocks and soils for clues to past water activity on Mars. In its time on the Red Planet, Opportunity discovered small spheres of the mineral hematite, which typically forms in water. In addition to these spheres that a scientist nicknamed “blueberries,” the rover also found signs of liquid water flowing across the surface in the past: brightly colored veins of the mineral gypsum in rocks, for instance, which indicated water flowing through underground fractures.


image



The small spheres on the Martian surface in this close-up image are near Fram Crater, visited by the Opportunity rover in April 2004.



For more about Opportunity’s adventures and discoveries, see: https://go.nasa.gov/ThanksOppy.


Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com


New technique pinpoints milestones in the evolution of bacteria

Bacteria have evolved all manner of adaptations to live in every habitat on Earth. But unlike plants and animals, which can be preserved as fossils, bacteria have left behind little physical evidence of their evolution, making it difficult for scientists to determine exactly when different groups of bacteria evolved.











New technique pinpoints milestones in the evolution of bacteria
An exoskeleton-consuming gene found in bacteria sheds light on the first arthropods
 to walk the Earth [Credit: MIT News]

Now MIT scientists have devised a reliable way to determine when certain groups of bacteria appeared in the evolutionary record. The technique could be used to identify when significant changes occurred in the evolution of bacteria, and to reveal details about the primitive environments that drove such changes in the first place.


In a paper published in the journal BMC Evolutionary Biology, the researchers report using the technique to determine that, around 450 to 350 million years ago, during the Paleozoic Era, several major groups of soil bacteria acquired a specific gene from fungi that allowed them to break down chitin — a fibrous material found in the cell walls of fungi and in the exoskeletons of arthropods — and use its products to grow.


This evolutionary adaptation in bacteria may have been driven by a significant shift in the environment. Around the same time, arthropods such as early spiders, insects, and centipedes, were moving from the oceans onto land. As these terrestrial arthropods spread and diversified, they left behind chitin, creating richer soil environments and a new opportunity for bacteria — particularly those that acquired the chitinase gene — to thrive.


“Before this period, you would have had soils, but it might have looked like the dry valleys of Antarctica,” says Gregory Fournier, the Cecil and Ida Green Assistant Professor of Geobiology in MIT’s Department of Earth, Atmospheric, and Planetary Sciences. “With animals living in soils for the first time, that provided new opportunities for microbes to take advantage and diversify.”


Fournier says that, by tracing certain genes such as chitinase in bacteria, scientists can gain new insight into the early history of animals and the environments in which they lived.


“Microbes contain in their genomes a shadow history of animal life that we can use to fill gaps in our understanding of not only microbes, but also of the early history of animals,” Fournier says.


The paper’s authors include lead author Danielle Gruen PhD ’18, and former postdoc Joanna Wolfe, now a research scientist at Harvard University.


Missing fossils


Without a fossil record, scientists have used other techniques to lay out bacteria’s “tree of life” — a map of genetic relationships, showing many branches and splits as bacteria have evolved into hundreds of thousands of species through time. Scientists have established such maps by analyzing and comparing the gene sequences of existing bacteria.


Using a “molecular clock” approach, they can estimate the rates at which certain genetic mutations may have occurred, and calculate the time at which two species may have diverged.


“But that can only tell you relative time, and there’s a huge uncertainty associated with these estimates,” Fournier says. “We have to anchor this tree somehow to the geological record, to absolute time.”


The team found they could use fossils from an entirely different organism to anchor the time at which certain groups of bacteria evolved. While in the vast majority of cases, genes are passed down through generations, from parent to offspring, every so often, a gene can hop from one organism to another, via a virus or through the environment, in a process known as horizontal gene transfer. The same genetic sequence, therefore, can appear in two organisms that otherwise would have entirely different genetic histories.


Fournier and his colleagues reasoned that if they could identify a common gene between bacteria and an entirely different organism — one with a clear fossil record — they might be able to pin bacteria’s evolution to the point at which this gene was transferred from the fossil-dated organism, to bacteria.


Splitting trees


They looked through the genome sequences of thousands of organisms and identified a single gene, chitinase, that appeared in several major bacterial groups, as well as in most species of fungi, which have a well-established fossil record.


They then used algorithms to produce a tree of all the different species with the chitinase genes, showing the relationships between species based on mutations in their genomes. Next, they employed a molecular clock approach to determine the relative times at which each species of bacteria containing chitinase branched from its respective ancestor. They repeated this same process for fungi.


The researchers traced chitinase in fungi to the point at which it most resembled the gene when it first appeared in bacteria, and reasoned that that must have been when fungi transferred the gene to bacteria. They then used fungi’s fossil record to pinpoint the time at which transfer likely occurred.


They found that, following the subsequent transfer of this gene across several groups of bacteria, three major groups of soil bacteria containing the chitinase gene all diversified around 450 to 350 million years ago. This rapid burst of microbe diversity was likely in response to a similar diversification of land animals, and specifically, chitin-producing arthropods, which occurred around this same period, as the fossil record shows.


“This result supports [the idea] that microbial groups tend to acquire genes for using resources as soon as they are available in the environment,” Fournier notes. “In principle, this approach can therefore be used to date many more groups of microbes, using the transfer of other genes that use other resources.”


Fournier is now developing an automated pipeline for detecting useful gene transfers between bacteria and other organisms, from huge amounts of gene data. For instance, he is looking at microbial genes responsible for breaking down collagen, a compound that is produced only in animals, and is found in soft body tissues.


“If we have a shadow history in the microbes of genes that eat soft body tissue, we could maybe reconstruct the early history of soft body tissues, which don’t preserve well in the fossil record,” Fournier says.


Author: Jennifer Chu | Source: Massachusetts Institute of Technology [February 07, 2019]



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DNA provides insights into penguin evolution and reveals two new extinct penguins

New University of Otago research has improved our understanding of when and why penguins evolved, and has identified two recently extinct penguins from New Zealand’s remote Chatham Islands.











DNA provides insights into penguin evolution and reveals two new extinct penguins
This original artwork shows Eudyptes warhami in the foreground, with Megadyptes antipodes richdalei
in the background [Credit: Sean Murtha]

In the study, published online today in the scientific journal Molecular Biology and Evolution, an international team of researchers sequenced mitochondrial genomes from all living and recently extinct penguin species. By analysing the genetic relationships of species, and using ancient fossil penguins to put a time scale on these, the team showed that many penguin species arose soon after the geological formation of islands, including those inhabiting the Antipodes and Chatham Islands, Macquarie Island, Gough Island and Galápagos Islands.


Lead author of the study, Otago University PhD candidate Theresa Cole, says: “From an evolutionary perspective, it’s fascinating to understand how and why species evolve. We were able to provide a comprehensive framework for exploring these questions about penguins, and demonstrated for the first time that islands may have played a key role in penguin evolution.”


The study, which included sequencing DNA and examining hundreds of prehistoric bones across New Zealand, also confirmed that a now extinct, unique crested penguin species existed on the Chatham Islands until a few centuries ago.


The former existence of this species had long been suspected by study co-author Alan Tennyson of Te Papa, who had previously examined penguin bones from these islands. However the study also threw up a complete surprise – revealing that a previously unknown small subspecies of yellow-eyed penguin also once existed on the Chatham Islands.











DNA provides insights into penguin evolution and reveals two new extinct penguins
Composite fossil skull of Eudyptes warhami, an extinct penguin species from the Chatham Islands
[Credit: Jean-Claude Stahl]

Study authors, including Cole, Tennyson, Daniel Thomas from Massey University, Dan Ksepka from the US Bruce Museum, named the two new penguins Eudyptes warhami and Megadyptes antipodes richdalei in honour of John Warham and Lance Richdale, who carried out pioneering studies on penguins in New Zealand.


“Evidence suggests Eudyptes warhami and Megadyptes antipodes richdalei inhabited the Chatham Islands up until the last few hundred years, and became extinct only after humans arrived,” Cole says. “The discovery of these two new penguins adds greatly to our understanding of how humans impacted New Zealand’s marine biodiversity in the past.”


“The more we learn about New Zealand’s past ecosystems, the more we realise how dramatically they have changed since human arrival.” says Otago Professor Jon Waters, who helped supervise the study.


This new study follows another led by Cole and published recently in the journal Molecular Phylogenetics and Evolution, which used ancient DNA to show that prehistoric penguin bones from New Zealand included several species that no longer breed there.


The researchers are now extending the study by sequencing whole genomes to explore penguin evolution and adaptation.


Source: University of Otago [February 07, 2019]



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Asteroid from ‘rare species’ sighted in the cosmic wild

Astronomers have discovered an asteroid looping through the inner solar system on an exotic orbit. The unusual object is among the first asteroids ever found whose orbit is confined almost entirely within the orbit of Venus. The asteroid’s existence hints at potentially significant numbers of space rocks arcing unseen in uncharted regions nearer to the sun.











Asteroid from 'rare species' sighted in the cosmic wild
The orbit of asteroid 2019 AQ3, discovered by ZTF, is shown in this diagram. The object has
the shortest “year” of any recorded asteroid, with an orbital period of just 165 days
[Credit: NASA/JPL-Caltech]

A state-of-the-art sky-surveying camera, the Zwicky Transient Facility, or ZTF, detected the asteroid on January 4, 2019. Designated 2019 AQ3, the object has the shortest “year” of any recorded asteroid, with an orbital period of just 165 days. It also appears to be an unusually big asteroidal specimen.


“We have found an extraordinary object whose orbit barely strays beyond Venus’ orbit—that’s a big deal,” said Quanzhi Ye, a postdoctoral scholar at IPAC, a data and science center for astronomy at Caltech. Ye called 2019 AQ3 a “very rare species,” further noting that “there might be many more undiscovered asteroids out there like it.”


ZTF is installed on the 48-inch Samuel Oschin Telescope at the Palomar Observatory, located about 122 miles south-east of Los Angeles. It began operations in March 2018 and has already observed more than a billion Milky Way stars, as well as over a thousand of supernovae outside the Milky Way, and other extreme transient cosmic events. ZTF was made possible by funding from the National Science Foundation (NSF). Asteroid research with ZTF is also directly funded by NSF through support of Ye as a Caltech postdoctoral scholar.


A chief science goal of ZTF is rounding up near-Earth asteroids (NEAs), which along with comets that buzz our planet are known as near-Earth objects (NEOs). Scientists at ZTF are especially interested in finding NEAs between about 10 and 100 meters in diameter—not monstrous in size, but that could still be large enough to severely impact a city should they collide with Earth. Of this potentially Earth-bound set of space rocks, the most concerning are those that come from the direction of the sun, which get lost in the glare and are difficult to measure.


“These small asteroids are only bright enough to be detected during the short period that they are very close to the Earth,” said Tom Prince, the Ira S. Bowen Professor of Physics at Caltech with a joint appointment as a senior research scientist at the Jet Propulsion Laboratory, managed by Caltech for NASA, who works on finding NEOs using ZTF. “During this brief window, the asteroids are moving very fast, posing challenges for astronomers to find and track them.”


To have any hope of locating such objects, the sky must be scanned very frequently. ZTF surveys the entire northern visible sky every three nights. This excellent coverage comes courtesy of its vast field of view, which in a single exposure, can image approximately two hundred and thirty times the size of the full moon. “The large field-of-view makes ZTF an ideal instrument to find and track rare objects, such as near-Earth asteroids,” said Frank Masci, a Staff Scientist at Caltech / IPAC, who oversees and manages the ZTF science data processing system, which is located at IPAC. “ZTF is definitely up to the game.”


Leveraging ZTF’s capabilities, Ye and Wing-Huen Ip—a professor of astronomy and space science at the Institute of Astronomy and Space Science at the National Central University in Taiwan—proposed the Twilight Survey, which looks for asteroids inbound from the sun. This survey turned up 2019 AQ3 and could yield other interesting asteroids down the road.


A history of asteroidal and cometary successes


Finding NEOs before they find us has long been a major topic at Caltech / IPAC. The center has led the science operations and data processing for NASA’s Wide-field Infrared Survey Explorer (WISE) and NEOWISE missions since their launch in 2009. This asteroid hunter has discovered more than 34,000 new asteroids, including nearly 300 NEAs. ZTF”s predecessor, the Palomar Transient Factory, likewise revealed a bevy of NEOs during its sky survey.


“The sizes of NEOs are best estimated by combining visible and infrared data, which is precisely what we strive to do here at IPAC,” said George Helou, Research Professor of Physics at Caltech and the Executive Director of IPAC. “Since its inception, IPAC has been involved in infrared studies of asteroids.”


So far, ZTF has logged nearly 60 new near-Earth asteroids. Two of these were spotted in July 2018 mere hours before they gave Earth quite a close shave. Designated 2018 NW and 2018 NX, the duo of bus-sized asteroids whipped past at a distance of about 70,000 miles, or only a third of the way to the moon. Fortunately, the newfound 2019 AQ3 poses no threat; the closest it ever comes to Earth is about 22 million miles.


Tracking down 2019 AQ3


The story of how researchers nailed down 2019 AQ3’s orbit begins with Ye noting the object in ZTF’s images on January 4, 2019. Ye reported the object to the IAU Minor Planet Center, the official worldwide organization charged with gathering data on sun-orbiting objects that are not full planets, such as asteroids and comets. Ye then spent some time mining the ZTF images taken before and after this date to improve projections of the asteroid’s orbit.


Two days later, Marco Micheli, a scientist at the European Space Agency, pointed out the target’s uniqueness to the global astronomical community. Multiple other telescopes observed 2019 AQ3 on January 6 and 7, further documenting its uniqueness. A dig through the archives of the Pan-STARRS 1 telescope at the Haleakalā Observatory on the island of Maui, Hawaii, turned up evidence of 2019 AQ3 going back to 2015. With those data in hand, astronomers confidently mapped the object’s complete path around the sun.


The orbit, as it turns out, is angled vertically, taking 2019 AQ3 above and below the plane where the planets run their laps around the sun. Over its short year, 2019 AQ3 plunges inside of Mercury, then swings back up just outside of Venus’ orbit.


For now, 2019 AQ3 is placed among a peculiar population usually referred to as the Atira or Apohele asteroids, which have orbits interior to Earth’s orbit. Among the approximately 800,000 known asteroids, only 20 or so are Atiras. Far greater numbers of these potentially dangerous space rocks are thought to exist, however, the discovery and characterization of which are among the motivations behind the proposed Near-Earth Object Camera (NEOCam) infrared space telescope. Presently funded by NASA for an extended concept study phase, NEOCam is designed to look closer to the sun than previous surveys, which would empower it to pick out hidden asteroids that have long defied detection.


Learning more about known and newfound Atiras, for example their sizes, is an additional goal of ZTF and its fellow instruments. Although the true size of 2019 AQ3 is not yet discernible, limited readings relating to the asteroid’s brightness, mass, and density suggest it could be nearly a mile across. If so, 2019 AQ3 would stack up as one of the largest members of the exclusive Atiras group. “In so many ways, 2019 AQ3 really is an oddball asteroid,” said Ye.


Finding more space rocks in 2019 AQ3’s neck of the woods could lend credence to the long-held idea of vulcanoids—asteroids that swarm inside the orbit of Mercury. The hypothetical population’s name derives from a likewise hypothetical planet, Vulcan. Bearing no relation to the fictional home world of Mr. Spock in Star Trek, Vulcan was proposed in the 19th century as the planet closest to the sun whose gravity would explain anomalies measured in Mercury’s orbit. Albert Einstein’s gravitational framework, the theory of general relativity, explained away these anomalies in 1915, nixing the Vulcan conjecture.


Although ZTF will not have the ability to find vulcanoids, its observing prowess, coupled with that of future telescopes, will enable scientists to at last examine an uncharted region in the inner solar system. ZTF should turn up fresh surprises, as well as give old ideas new chances of being substantiated. “The origin of Atiras is an intriguing and open question,” said Ip. “With every additional object, we get closer to formulating and testing models about that origin, and about the history of our Solar System.”


For more information about the data in this release visit the IAU Minor Planet Center.


Source: California Institute of Technology [February 08, 2019]




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Case study documents bone cancer in 240-million-year-old stem-turtle

Bone cancer has been found in a prehistoric ancestor of the turtle that swam the seas 240 million years ago.











Case study documents bone cancer in 240-million-year-old stem-turtle
Morphology of Osteosarcoma on Fossil Stem-Turtle Femur: A micro-computed tomography scan shows the undisturbed
cortical bone and the extent of the periosteal mass (circled area). CB indicates cortical bone; OS, osteosarcoma;
SP, spicular outgrowth. The black scale bar represents 1 cm [Credit: JAMA Oncology (2019)]

The tumour was identified in the thigh of a primitive animal known as a shell-less stem turtle. It was highly malignant and aggressive, meaning the creature would have been in pain.


Early turtles didn’t have shells and some were up to eight feet long with a beak and a very long tail. Their broad ribs, flat bodies and strong limbs were adapted for digging in the mud to bury its eggs or forage for food on the bottom of shallow waters near the shore.


The turtle lived during the Triassic at a time when the first dinosaurs were just beginning to appear – suggesting otherwise.


Yara Haridy, a master of science at the Natural History Museum, Berlin, said: “This study provides evidence tumours occurred as early as the Triassic period and that cancer is not a modern physiological defect but rather a vulnerability that is rooted deep in vertebrate evolutionary history. The appearance of the tumour in the fossilised specimen conforms with present-day osteosarcoma in humans.”











Case study documents bone cancer in 240-million-year-old stem-turtle
Micro-computed Tomography (CT) Virtual Thin Sections of Osteosarcoma on Triassic Stem-Turtle Femur:
A, The red lines represent the locations of the thin sections shown in panels B and C. The white scale
bars on panels B and C represent 1 mm. CB indicates cortical bone; MC, medullary cavity;
OS, osteosarcoma [Credit: Jama Oncology (2019)]

Osteosarcoma is the most common type of bone cancer and can develop anywhere in the body, and most commonly strikes teenagers and young adults. Its illness helps provide more data about the history of cancer in tetrapods. This includes all species of four limbed animals – including humans, said lead author Ms Haridy.


She said: “This is a case study about a highly malignant bone tumour on the thigh bone of a shell-less stem-turtle.”


The reptile was unearthed in the town of Vellberg, south west Germany, in 2013. Its deadly illness was identified under powerful microscopes and scanners.


The most affected region was at the back of the left leg, towards the hip joint. It is oldest instance of bone cancer in a reptile, bird or mammal, said the researchers.











Case study documents bone cancer in 240-million-year-old stem-turtle
Artistic reconstruction of Pappochelys rosinae [Credit: WikiCommons]

Named Pappochelys rosinae, meaning ‘grandfather turtle’ in Greek, it had a wide body, small skull and was only about eight inches long, including its long tail.


The skull was pointed with large eye sockets. There were several turtle-like features including expanded ribs and other bones that appeared to be the precursors of a shell.


Paleopathology, the study of ancient disease, is a vital way by which we understand the evolution of pathogens, immune systems, healing and the environment.


Ms Haridy said: “Cancer research has focused on its prevalence in various organisms and has found that although some animals have a high propensity for cancer, others seem to be resistant. ‘The prevalence of cancer in the tree of life is certainly interesting, but its antiquity should be regarded with equal interest considering the increase in human cancer, which has been related to environmental and genetic changes, and the extreme rarity of cancer in the fossil record.”


The earliest known case of bone cancer in a human was recently discovered in the toe of an early ancestor who died in Swartkrans Cave, South Africa, between 1.6 and 1.8 million years ago.


The full findings of the study were published in the journal JAMA Oncology.


Author: Tim Collins | Source: Daily Mail [February 08, 2019]



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Diverse scents of woodland star wildflowers driven by coevolution with pollinators

A study of woodland star wildflowers in the western United States has found remarkable diversity in the scent compounds produced by their flowers. Every species of woodland star, and even different populations within a species, may produce a unique floral bouquet, sometimes composed of dozens of scent compounds, to attract specialized insect pollinators.











Diverse scents of woodland star wildflowers driven by coevolution with pollinators
The moth Greya politella pollinates Lithophragma flowers while laying its eggs in the flowers,
as seen in this photo of the moth on a flower cut open to show the inside of the flower
[Credit: John Thompson]

Twelve species and subspecies of woodland star (Lithophragma) occur in a wide range of habitats throughout western North America. They have coevolved with a group of specialized moths, called Greya moths, that pollinate and lay eggs only in woodland star flowers. Although the plants lose some of their developing seeds to the moth larvae, the benefits the plants receive from pollination usually outweigh the costs.


The floral scent study, published in Proceedings of the National Academy of Sciences, adds a surprising new layer to the complex relationship between woodland stars and their pollinators. Senior author John Thompson, professor of ecology and evolutionary biology at UC Santa Cruz, has been studying the coevolution of these species for several decades. The new study builds on previous work showing that the interactions of woodland star with Greya moths have widely varying outcomes in different ecosystems depending on which pollinators are present.


“We had already shown in previous studies that the moths can find their local host plants using only the floral bouquets produced by the local Lithophragma plants. So we knew that floral scent was important to the plants and the moths,” Thompson said.


He and his collaborators set out to characterize the floral scents produced by each Lithophragma species in a wide range of ecosystems and see just how different they are. The researchers sampled almost a hundred populations of woodland stars in ecosystems from southern California to Washington. Although they expected to find at least some differences in the floral bouquets, the results were surprising.


The first surprise was that the floral bouquets include an unexpectedly large number compounds. Many populations the researchers sampled had scents composed of more than 20 compounds, and some populations emitted almost 50 different kinds of scent molecules. A second surprise was that the compounds in these bouquets arise from a wide range of biosynthetic pathways, rather than one or a few pathways.


“These flowers are making a lot of scent compounds, both in number and in the diversity of biochemical pathways, and natural selection has mixed and matched the biochemistry of floral bouquets in very different ways among different populations,” Thompson said.











Diverse scents of woodland star wildflowers driven by coevolution with pollinators
UC Santa Cruz researchers collected scent compounds from woodland star flowers at field sites
across the western United States [Credit: Magne Friberg]

One local population may have a bouquet dominated by a variety of terpenes supplemented with a few other kinds of compounds. A population in another ecosystem may have a bouquet dominated by nitrogenous compounds, and yet others by aromatic esters or ethers. Why populations should differ so greatly in the biochemistry of their bouquets is not yet clear, but part of the answer may be in the ways that plant chemistry evolves with other traits as natural selection molds local adaptation of these plants to their pollinating moths.


There are two different Greya moth species, and they select for different floral morphologies because of differences in how they pollinate the flowers. So a population’s flower shape often depends on which moth species is present. Furthermore, the researchers have found that different scent compounds are produced by different parts of the flower, so changes in floral morphology may affect scent production.


In addition to the Greya moths, other insects that are less specialized may also pollinate woodland star flowers in some ecosystems. In those sites, the presence of other pollinators disrupts the tight coevolution between flowers and moths, and Lithophragma may even evolve to exclude Greya moths (by aborting flowers in which the moths have laid eggs) to avoid paying the cost of losing seeds to moth larvae.


“There are several components to this interaction,” Thompson explained. “What creates a geographic mosaic of populations with different traits is the tight coevolution between flowers and moths in some environments, which gets swamped in other environments by the presence of different pollinators.”


The background of competing scents in different ecosystems may also influence floral scents. “The plants need to attract their pollinators in the presence of a huge array of other chemicals in that environment, so they come up with a unique signal,” Thompson said. “Also, we don’t have the insect side of this yet. These plants make a lot of scent compounds, but which ones can the moths detect?”


These studies are part of a long-term effort to understand how the process of coevolution works in nature and how it shapes and reshapes the adaptation of species over broad geographic scales.


“As we’ve learned more about coevolution, one of the things we’ve come to realize is just how complex the traits are that coevolve among species,” Thompson said. “These are the kinds of studies we need if we are to make scientifically informed plans for conserving the Earth’s many highly coevolved interactions at a time when environments are changing quickly. These results tell us that species coevolve as a geographic mosaic in which each local interaction between species may include unique evolutionary solutions. If we are to conserve species in a world in which environments are changing rapidly, we need to conserve as many of these links as possible.”


Source: University of California – Santa Cruz [February 11, 2019]



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Six Things to Know About NASA’s Opportunity Mars Rover


NASA – Mars Exploration Rover B (MER -B) patch.


Feb. 13, 2019



Image above: This scene from the panoramic camera on NASA’s Mars Exploration Rover Opportunity looks back toward part of the west rim of Endeavour Crater that the rover drove along, heading southward, during the summer of 2014. Image Credits: NASA/JPL-Caltech/Cornell/ASU.


After 15 years, the mission of NASA’s Opportunity rover has come to an end, but its successes on Mars have earned it a spot in the robot hall of fame. Here’s what you need to know about our intrepid Martian overachiever:


1. Opportunity was a twin.



Image above: This infographic highlights NASA’s twin robot geologists, the Mars Exploration Rovers (MER) Spirit and Opportunity. Image Credits: NASA/JPL-Caltech.


The Mars Exploration Rovers mission featured two identical, golf-cart-sized, solar-powered rovers: Spirit and Opportunity. Spirit landed at Gusev Crater on Jan. 4, 2004. Opportunity landed on the opposite side of Mars at Meridiani Planum on Jan. 24, 2004 PST (Jan. 25 EST). Both rovers were managed for NASA by NASA’s Jet Propulsion Laboratory in Pasadena, California.


2. Opportunity and Spirit showed that Mars had the wet and warm conditions in its ancient past that were potentially hospitable to life.



Image above: The small spherules on the Martian surface in this close-up image are near Fram Crater, visited by NASA’s Mars Exploration Rover Opportunity during April 2004. Image Credits: NASA/JPL-Caltech/Cornell/USGS.


Foremost among Spirit and Opportunity’s many science discoveries: Mars was likely wetter and warmer in the past. These conditions could have served as a cradle for life on Mars at a time when life first emerged on Earth.


Opportunity contributed several key findings to this conclusion. It was the first rover to identify and characterize sedimentary rocks on a planet other than Earth. Opportunity’s measurements showed these rocks formed in ancient ephemeral playas. Opportunity also discovered small spheres of hematite nicknamed “blueberries” that formed late from rising, acidic groundwater. Once Opportunity reached the rim of Endeavour crater, the rover found white veins of the mineral gypsum — a telltale sign of water that traveled through underground fractures. Opportunity also found more compelling signs of Mars’ watery past in the rocks of Endeavour Crater: clay minerals that formed in neutral-pH (not too acidic, not too basic) water. Of all the places studied by Opportunity, the environment at Endeavour had the friendliest conditions for ancient microbial life.


3. Opportunity is an off-world record holder.



Image above: NASA’s Mars Exploration Rover Opportunity used its panoramic camera to record this eastward horizon view on the 2,407th Martian day, or sol, of the rover’s work on Mars (Oct. 31, 2010). Image Credits: NASA/JPL-Caltech/Cornell University.


Opportunity worked longer on the surface of Mars than any other robot — more than 14 years. This far exceeded the original 90-day mission planned for Opportunity and Spirit.


During Opportunity’s time on Mars, it also drove a total of 28.06 miles (45.16 kilometers), clinching the record for longest drive on another world in 2014.


4. Opportunity was the little rover that could.



Image above: This scene from the panoramic camera (Pancam) of NASA’s Mars Exploration Rover Opportunity catches “Pillinger Point,” on the western rim of Endeavour Crater, in the foreground. It is presented in false color to make differences in surface materials more easily visible. Image Credits: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.


Opportunity didn’t survive for over 14 years because its mission was easy. It encountered challenges that required its engineers to be resourceful. For instance, the rover’s right-front wheel sometimes drew more current than the other wheels, so engineers often drove the rover backward to extend the right front wheel’s life.


The terrain was treacherous. After the rover landed at Eagle Crater, its wheels slipped on the loose slopes when it first attempted to drive out of the crater. Rover planners had to come up with creative driving strategies to get out — something they did again at Endurance Crater, where slopes were as steep as 31 degrees. On April 26, 2005, Opportunity’s wheels dug into a soft, wind-sculpted sand ripple and got stuck for several nail-biting weeks at “Purgatory Dune.” But after extensive testing in a Mars-like sandbox at JPL, the team was able to carefully shimmy out of the Martian sand trap.


Opportunity encountered two mission-threatening dust storms that blocked sunlight from reaching its solar panels. It survived a dust storm in 2007 by minimizing activities and maintaining enough power in its batteries to recover when the skies cleared. Unfortunately, the 2018 dust storm blotted out even more sunlight and kept the skies above Opportunity dark about a month longer.


5. Opportunity and Spirit showed us the beauty of Mars.



Image above: From its perch high on a ridge, NASA’s Mars Exploration Rover Opportunity recorded this image of a Martian dust devil twisting through the valley below. The view looks back at the rover’s tracks leading up the north-facing slope of “Knudsen Ridge,” which forms part of the southern edge of “Marathon Valley.” Image Credits: NASA/JPL-Caltech.


Opportunity and Spirit were avid documentarians, giving us a human-scale view of what it was like to be on Mars. They returned over 342,000 raw images, which were promptly posted online for everyone’s enjoyment. These two rovers also produced 31 stunning 360-degree color panoramas.


The most memorable images Opportunity took — including ripples of sand that resembled waves on water, patches of jumbled rock on a crater rim, whirling dust devils and its own tracks along a ridge — revealed the otherworldly beauty of Mars and the drama of exploration.


6. The story of Opportunity and Spirit is not over. Their lessons live on in current and future Mars missions. 



Image above: In this navigation camera raw image, NASA’s Opportunity Rover looks back over its own tracks on Aug. 4, 2010. NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the Mars Exploration Rover Project for NASA’s Science Mission Directorate, Washington. Image Credits: NASA/JPL-Caltech.


The success of the Mars Exploration Rovers helped drive the growth of NASA’s Mars program, building support for orbiters and new kinds of rovers. Spirit and Opportunity showed how mobile robots on Mars could communicate reliably with Earth (either directly or by employing orbiters around Mars as relays back to our home planet), use 3-D vision to navigate the Martian terrain and make autonomous science observations.


Curiosity and the upcoming Mars 2020 rovers build upon the lessons of Spirit and Opportunity. And scientists will continue to make new discoveries from the Mars Exploration Rovers data for years to come.



Mars Exploration Rover (MER). Image Credits: NASA/JPL-Caltech

Spirit and Opportunity have been a fertile training ground for the many hundreds of engineers and planetary scientists who have learned at their robotic knees. A number have gone on to lead other space missions. Many of those currently operating Opportunity are sharing their expertise part-time with other missions exploring our solar system. For most, working on Spirit and Opportunity has been transformative. You can read many of their stories here: https://www.jpl.nasa.gov/opportunity-memories/


For more highlights of the Mars Exploration Rover mission, visit: https://mars.nasa.gov/mer/highlights/


Images (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Jia-Rui Cook.


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Crew Studies Human Body and Checks Cooling Systems


ISS – Expedition 58 Mission patch.


February 13, 2019


Wednesday saw the Expedition 58 crew explore the inner workings of the human body in space and maintain cooling systems aboard the International Space Station.


NASA astronaut Anne McClain spent all day setting up cooling gear inside the U.S. Destiny lab module and Japan’s Kibo lab module. She drained and refilled water pumps inside the Fluid System Servicer and the Internal Thermal Control System. The life support systems help cool the station’s atmosphere and dispel heat generated by electrical systems.



Image above: Astronaut David Saint-Jacques (right) of the Canadian Space Agency becomes a barber aboard the International Space Station and trims Expedition 58 Commander Oleg Kononenko’s hair with clippers attached to a vacuum hose. Image Credit: NASA.


Microgravity’s impact on the human physiology was the focus of Flight Engineer David Saint-Jacques’ day. The Canadian Space Agency astronaut collected and stowed his breath, blood and urine samples for a variety of human research experiments. The research is supporting the long term-collection of human biological samples and observing bone marrow and blood changes.


Saint-Jacques also conducted ultrasound scans in the Zvezda service module for the Fluid Shifts study with assistance from Commander Oleg Kononenko and doctors on the ground. That research is seeking to reverse increased head and eye pressure that occurs in space.



International Space Station (ISS). Image Credit: NASA

Kononenko started Wednesday servicing Russian life support systems. The four-time station resident then spent the afternoon on more space research studying motion coordination, radiation exposure and crew psychology.


Related links:


Expedition 58: https://www.nasa.gov/mission_pages/station/expeditions/expedition58/index.html


Destiny lab module: https://www.nasa.gov/mission_pages/station/structure/elements/us-destiny-laboratory


Kibo lab module: https://www.nasa.gov/mission_pages/station/structure/elements/japan-kibo-laboratory


Long term-collection of human biological samples: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=954


Bone marrow and blood changes: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1673


Zvezda service module: https://www.nasa.gov/mission_pages/station/structure/elements/zvezda-service-module.html


Fluid Shifts: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1126


Motion coordination: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1594


Radiation exposure: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=633


Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html


International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html


Images (mentioned), Text, Credits: NASA/Mark Garcia.


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