In the store-rooms of the National Museum of American History curators recently discovered a small microscope made around 1750 by John Cuff (1708-1772), a talented instrument maker whose shop was found “directly against Serjeant’s-Inn Gate in Fleet-Street,” London. Click here to learn more.
Articles on this Page
- 10/15/15--05:31: _Climbing plants dis...
- 10/29/15--04:53: _Nano Bible donated ...
- 12/02/15--09:42: _Smithsonian lab rec...
- 12/22/15--05:37: _Research shows same...
- 12/23/15--13:48: _The Power of Touch:...
- 01/07/16--12:20: _Trees employ simila...
- 01/19/16--12:26: _Elusive bush dog wi...
- 02/16/16--10:58: _invasive cobia spre...
- 02/22/16--08:39: _‘The Wrong Wrights’...
- 01/12/15--04:42: _Asteroids: Breaking...
- 01/30/15--11:36: _Reptile rejuvenatio...
- 02/13/15--05:18: _Mismatched Twin Sta...
- 04/21/15--08:04: _Panda Semen from Ch...
- 04/28/15--10:45: _Water may Have Been...
- 05/11/15--05:51: _Scientists Find And...
- 05/14/15--06:02: _The oldest microsco...
- 05/28/15--09:39: _Geologic Mapping of...
- 06/24/15--09:22: _Oasis in the city
- 07/08/15--10:18: _Smithsonian and Par...
- 07/15/15--11:41: _A Precocious Black ...
- 10/15/15--05:31: Climbing plants disturb carbon storage in tropical forests
- 10/29/15--04:53: Nano Bible donated to Smithsonian
- 12/02/15--09:42: Smithsonian lab receives GreenGov Presidential Award
- 12/22/15--05:37: Research shows same growth rate for farming, non-farming societies
- 12/23/15--13:48: The Power of Touch: Sex-changing snails switch sooner when together
- 01/07/16--12:20: Trees employ similar strategies to outcompete their neighbors
- 01/19/16--12:26: Elusive bush dog widespread in Panama
- 02/16/16--10:58: invasive cobia spreads in Panama
- 02/22/16--08:39: ‘The Wrong Wrights’: A Graphic Novel from Smithsonian Books
- 01/12/15--04:42: Asteroids: Breaking up is Hard to Do
- 01/30/15--11:36: Reptile rejuvenation at National Zoo
- 02/13/15--05:18: Mismatched Twin Stars Spotted in the Delivery Room
- 04/21/15--08:04: Panda Semen from China arrives at Zoo
- 04/28/15--10:45: Water may Have Been Abundant in First Billion Years after big bang
- 05/11/15--05:51: Scientists Find Andean Bears with Camera Traps In Peru
- 05/14/15--06:02: The oldest microscope in the museum
- 05/28/15--09:39: Geologic Mapping of Mars
- 06/24/15--09:22: Oasis in the city
- Make sure that the garden offers a host source and a pollen source. There would be no butterflies or beetles to pollinate the different flowering plants if there are no caterpillars or larvae first. Make sure that the larvae or caterpillars’ essential food sources (for example, milkweed for monarch caterpillars) are available.
- Plant a variety of plants with differing flower shapes, colors, and bloom times to attract a diverse group of pollinators. Different pollinators have different methods of pollination. A variety of plants helps to give that pollinator the opportunity to find the plant that works best for them.
- Planting native species for that area in the garden is one of the most efficient and sustainable ways to support your local pollinators.
- 07/08/15--10:18: Smithsonian and Partners To Preserve Earth’s Genomic Plant Diversity
- 07/15/15--11:41: A Precocious Black Hole
Although useful to Tarzan, vines endanger tropical forests’ capacity to store carbon. In a major experimental study in Panama, Smithsonian researchers showed that woody vines, or lianas, slow tropical forest tree growth and may even cause premature tree death. Lianas reduced aboveground carbon uptake by more than three-quarters, threatening the forests’ ability to buffer climate change.
Tropical forests account for a third of the total carbon fixed by photosynthesis. Lianas’ increasing abundance may be driven by changing climate, increased disturbance or by more severe seasonal drought. By reducing the ability of tropical forests to accumulate and store carbon released through burning fossil fuels, lianas could cause a positive feedback loop, accelerating climate change.
“This study has far-reaching ramifications,” said co-author Stefan Schnitzer, a biology professor at Marquette University and a long-term research associate at the Smithsonian Tropical Research Institute. “Lianas contribute only a small fraction of the biomass in tropical forests, but their effects on trees dramatically alter how carbon is accumulated and stored.”
Proceedings of the National Academy of Sciences published the article co-authored by Geertje van der Heijden, a postdoctoral fellow at STRI and in Schnitzer’s lab, and Jennifer Powers, a professor at the University of Minnesota.
Lianas are characteristic of lowland tropical forests, often making up more than 25 percent of species and woody stems. Because they depend on trees for support as they climb into sunlit treetops, they can invest a greater percentage of their own biomass in leaves.
Previous research by Schnitzer and colleagues showed that lianas can have significant negative effects on forest biomass growth and accumulation. These studies, however, focused primarily on tree growth, were restricted to forest gaps or were only observational. In this experimental study in Panama’s Barro Colorado Nature Monument, all lianas were cut in eight experimental plots in a 60-year-old secondary forest, but were left intact in eight others. For the next three years, researchers monitored the growth in diameter of trees and lianas in the plot, and collected and weighed dead leaves and other debris falling from the forest canopy.
By the third year, lianas reduced net biomass accumulation by 76 percent per year in plots where they were present compared to where they had been removed. This decrease was due both to lower tree growth and to an increase in tree mortality where lianas were present. The proportion of biomass in leaves versus wood differed as well: forest canopy productivity–mostly leaves–decreased by 14 percent in liana-free plots, while the productivity of woody stems rose by almost 65 percent. Lianas not only lowered biomass accumulation, but also shifted it from wood, which stores carbon for a long time, to leaves, which rot quickly and release carbon back to the atmosphere.
These results have dramatic implications for the capacity of tropical forests to serve as a sink for carbon in the future. Simulating the change of biomass stocks over the next 50 years in forests with lianas and without them, the authors found lianas could reduce long-term storage of carbon by 35 percent. Even greater reductions could take place if liana-tree competition intensifies due to the spread of lianas, or causes an increase in the fast-growing tree species with low wood density.
While lianas clearly reduce the capacity for tropical forests to store carbon, Schnitzer emphasizes that lianas are an important and valuable component of tropical forests: “In terms of carbon, lianas may be detrimental; however, lianas provide a wide range of resources for wildlife, such as fruits, seeds and fresh leaves, and by connecting trees together lianas provide aerial pathways that are used by the vast majority of arboreal animals to move through the forest.”
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Smithsonian Secretary David J. Skorton will accept a Nano Bible from Peretz Lavie, president of the Technion-Israel Institute of Technology, at the Smithsonian’s National Museum of American History on Oct. 30. The Nano Bible will be part of the Smithsonian Libraries collection, housed in the Dibner Library of the History of Science and Technology at the National Museum of American History.
The Nano Bible was produced by researchers at the Russell Berrie Nanotechnology Institute at the Technion-Israel Institute of Technology in Haifa, Israel. Engraved on a gold-plated silicon chip the size of a sugar grain, the bible’s text consists of more than 1.2 million letters carved with a focused beam of gallium ions. The text engraved on the chip must be magnified 10,000 times to be readable.
“We are excited to enrich the Libraries’ collections with this marvelous gift, which marries one of the world’s oldest and most significant texts with one of the newest technologies of the 21st century,” said Nancy E. Gwinn, director of Smithsonian Libraries. “As one of our principal values is to share our collections with the public, it is appropriate that the only copy in the United States be located here, as part of the national collections.”
At less than 100 atoms thick, the Nano Bible demonstrates how people can process, store and share data through tiny dimensions using nanotechnology. The Smithsonian’s Nano Bible will be the first one received in the United States.
Throughout 2015 the Smithsonian Environmental Research Center (SERC) in Edgewater, Md., has marked its 50th year of operation. Now there’s another reason for SERC to celebrate: One year after opening its Leadership in Energy & Environmental Design (LEED)-certified Mathias Laboratory, SERC has received a prestigious GreenGov Presidential Award for the building’s green design and sustainable operation.
The White House announced eight awards in seven different categories on Nov. 23. The recipients were people and projects that have made extraordinary achievements in the pursuit of President Obama’s Federal Sustainability goals.
As one of the most energy-efficient laboratories in the country, the Mathias Lab received the GreenGov Building the Future Award. The lab, which is LEED-certified “Platinum,” is the Smithsonian’s greenest building and emits 37 percent less carbon dioxide than a comparable laboratory that does not meet LEED standards.
“This award recognizes SERC’s commitment to lead a sustainable future and help reverse climate change; and it provides a wonderful facility for our innovative research on the most pressing environmental problems of the next 50 years,” says Anson Hines, SERC director.
The new laboratory’s specially designed features include:
• Roof-mounted panels that provide sun-heated hot water to an innovative interconnected system that recycles 100 percent of its water
• An HVAC system supplied by a large geothermal well field (250 wells 430 feet deep)
• Low-flow fume hoods for chemistry experiments
• Space for nearly 650 solar panels that provide almost 16 percent of the building’s electricity
With its completion, LEED certification and now the honor of a GreenGov Presidential Award, SERC’s Mathias Lab has set the bar high for the Smithsonian.
“Our current goal for all Smithsonian new construction and renovation is LEED Gold, but the Mathias Laboratory exceeded our policy by achieving LEED Platinum certification,” says Nancy Bechtol, director of Smithsonian’s Office of Facilities Engineering and Operations. “Our next objective is to build a Net Zero facility at SERC, and we are up for the challenge!”
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Prehistoric human populations of hunter-gatherers in a region of North America grew at the same rate as farming societies in Europe, according to a new radiocarbon analysis involving researchers from the University of Wyoming and the Harvard-Smithsonian Center for Astrophysics.
The findings challenge the commonly held view that the advent of agriculture 10,000-12,000 years ago accelerated human population growth. The research is reported this week in the Proceedings of the National Academy of Sciences, a major scientific journal.
“Our analysis shows that transitioning farming societies experienced the same rate of growth as contemporaneous foraging societies,” says Robert Kelly, University of Wyoming professor of anthropology and co-author of the PNAS paper. “The same rate of growth measured for populations dwelling in a range of environments, and practicing a variety of subsistence strategies, suggests that the global climate and/or other biological factors — not adaptability to local environment or subsistence practices — regulated long-term growth of the human population for most of the past 12,000 years.”
The lead author of the paper is Jabran Zahid of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. Erick Robinson, post-doctoral researcher in the University of Wyoming’s Department of Anthropology, also participated in the research.
While the world’s human population currently grows at an average rate of 1 percent per year, earlier research has shown that long-term growth of the prehistoric human population beginning at the end of the Ice Age was just 0.04 percent annually. That held true until about 200 years ago, when a number of factors led to higher growth rates.
For their research, the UW and Harvard-Smithsonian scientists analyzed radiocarbon dates from Wyoming and Colorado that were recovered predominantly from charcoal hearths, which provide a direct record of prehistoric human activity.
For humans in the region that is now Wyoming and Colorado between 6,000 and 13,000 years ago — people who foraged on animals and plants to survive — the analysis showed a long-term annual growth rate of 0.041 percent, consistent with growth that took place throughout North America. During that same period, European societies were farming or transitioning to agriculture, yet the growth rate there was essentially the same.
“The introduction of agriculture cannot be directly linked to an increase in the long-term annual rate of population growth,” the researchers wrote.
In general, similar rates of growth — around 0.04 percent — were measured for prehistoric human populations across a broad range of geographies and climates, the scientists say. “This similarity in growth rates suggests that prehistoric humans effectively adapted to their surroundings such that region-specific environmental pressure was not the primary mechanism regulating long-term population growth.”
Instead, the factors that controlled long-term population growth during that period likely were global in nature, such as climate change or biological factors affecting all humans, such as disease.
While concluding that population growth held steady overall at about 0.04 percent annually for thousands of years, the paper acknowledges that there were short-term fluctuations in human growth rates in certain regions lasting from a few hundred to 1,000 years. The authors suggest further statistical analysis of radiocarbon dates of human remains to study the mechanisms regulating population growth.
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Many animals change sex at some point in their lives, often after reaching a certain size. Snails called slipper limpets begin life as males, and become female as they grow. A new Smithsonian study shows that when two males are kept together and can touch one another, the larger one changes to female sooner, and the smaller one later. Contact, rather than chemicals released into the water, is necessary for the effect.
“I was blown away by this result,” said Rachel Collin, staff scientist at the Smithsonian Tropical Research Institute (STRI). “I fully expected that the snails would use waterborne cues to see their world.”
The article, co-authored by Collin and former STRI intern Allan Carrillo-Baltodano, now a pre-doctoral student at Clark University, was published in The Biological Bulletin.
Tropical slipper limpets, Crepidula cf. marginalis, live under rocks in intertidal areas along the shore, obtaining food by filtering plankton and other particles from the water. Their thin, flattened shells have a built-in shelf. When flipped over, they resemble men’s house slippers. Often found in clusters, they occur alone or as pairs or trios consisting of a large female with one or two smaller males riding piggyback on her shell.
A male limpet has a comparatively enormous penis–sometimes as long as his entire body–which rather incongruously emerges from the right side of his head. This elongated apparatus is necessary to extend around and under the female’s shell in order to reach her genital opening. When a snail changes sex, the penis gradually shrinks and then disappears at the same time that female organs develop. It is thought that this kind of sex change is advantageous because large animals are able to produce larger numbers of eggs as females, while small males can still produce plenty of sperm (which require much less energy to make than eggs).
In experiments, two males differing slightly in size were kept in small cups containing seawater. In some cups they were allowed to be in contact with one another, while in others a mesh barrier kept them apart while allowing water to pass through. The larger snails in the pairs in direct contact with their partners grew more quickly and changed into females sooner than those kept apart. Conversely, the smaller member of a pair that was in contact delayed sex change compared to ones separated by mesh.
In sex-changing coral-reef fishes, visual, behavioral and chemical cues may all influence switching by individuals that associate with each other. Slipper limpets, which are sedentary and have poor vision, were initially expected to depend more on waterborne chemical cues, already known to affect other aspects of their behavior. Surprisingly, slipper limpets turned out to be like fishes in showing a greater response to behavioral interactions or perhaps contact-based chemical cues, than waterborne signals.
“Slipper snails don’t move around much, so you don’t really think of them having complex reactions to each other,” Collin said. “But this study shows that there is more going on there than we thought.”
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How more than 1,000 tree species may occur in a small area of forest in Amazonia or Borneo is an unsolved mystery. Their ability to co-exist may depend on how trees get along with their neighbors. A new study based, in part, on data from the Smithsonian’s Forest Global Earth Observatory (ForestGEO) network shows that trees worldwide compete in some of the same ways, making simpler models of forest response to climate change possible.
Published in Nature, the study demonstrated how ‘personal’ traits such as wood density and leaf morphology influence a tree species’ ability to compete. There are trade-offs. Species with lighter wood usually grow more quickly than species with denser wood. But species with lighter wood also tend to die sooner and be poor competitors. Trees with dense tissues have more impact on their neighbors.
“We uncovered straightforward relationships between tree shape, growth rates and competitive abilities that organize tree communities around the world,” said S. Joseph Wright, co-author and staff scientist at the Smithsonian Tropical Research Institute in Panama.
Tree-to-tree interactions are difficult to study because trees grow slowly and are long-lived. Lead author Georges Kunstler of the Institut National de Recherche en Sciences et Technologies pour l’Environnement et l’Agriculture in France and colleagues used data from 3 million trees of 2,500 species growing at 140,000 sites from all forested biomes, to determine how traits influence tree competition. The study incorporated data from ForestGEO plots, coordinated by the Center for Tropical Forest Science at the Smithsonian Tropical Research Institute, including forest data from Barro Colorado Island, Panama; Luquillo, Puerto Rico; and Fushan, Taiwan.
Their findings strongly support a long-standing ecological idea about how forest succession influences tree diversity. In young forests, trees are more spread out, giving fast-growing species an advantage when there is little competition from surrounding trees. But as a forest matures and neighbors become more abundant, slower-growing trees win out because they are better competitors for resources like minerals, water and light. One of the most prominent ideas about how forest diversity is maintained is that trees can avoid competition by being different from their neighbors in the way they use resources and their life-history strategy. If this were the case, any trait could be advantageous as long as it was different from those of neighboring trees. Instead, this study shows that certain traits are more advantageous at different stages of forest succession whether or not they differ from those of neighbors.
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The bush dog is one of the most enigmatic of the world’s canid species, seldom seen throughout its range in Central and South America. New data from photos taken by automated camera traps in remote areas in Panama, along with other sightings, show the species to be widespread in the country. The new study, co-authored by Smithsonian Research Associate Ricardo Moreno, will assist conservation planning for this near-threatened species.
“Our group of biologists from Yaguará Panama and collaborators are working on an article about big mammals using camera trapping data that spans Panama from the Costa Rican border to the Colombian border,” Moreno said. “The bush dog is one of the rarest species that we photograph.”
Bush dogs, Speothos venaticus, are short-legged and stubby, standing only about a foot tall at the shoulder. They live mainly in tropical forests but have also been recorded in fragmented and altered habitats. Hunting in packs of up to 10 animals, bush dogs give high-pitched whines to maintain contact and yap like puppies when they chase their prey. They feed mostly on large forest rodents like agoutis and pacas, but at one site in Brazil, they mainly ate armadillos. Fierce for their size, a pack of six once was seen chasing a tapir, an animal almost 20 times a bush dog’s weight. Although active by day, bush dogs are remarkably hard to see and are very rarely reported even where they are known to occur.
Digital camera traps, which take pictures automatically when their infrared sensors detect an animal’s body heat, are used in many wildlife studies. Camera traps were set out as part of surveys for other mammals, including jaguars. The cameras fortuitously snapped photos of bush dogs at four sites ranging from Cerro Pirre near the Colombian border in eastern Panama, to Santa Fe National Park in the western part of the country. To give some idea of the difficulty of studying the species, photos were obtained on only 11 occasions out of more than almost 32,000 camera-days (the number of cameras multiplied by the number of days they were in operation).
The article reports bush dog sightings from five additional sites, including Fortuna west of Santa Fe, showing the species is found in suitable habitat nearly throughout Panama. Panama is the only country in Central America where the species is known to occur, aside from a few unconfirmed sightings in easternmost Costa Rica near the Panamanian border. “We think that it will soon cross the border into Costa Rica,” Moreno said.
The International Union for Conservation of Nature has estimated that bush dog populations have declined by up to 25 percent in the past 12 years, and has classified it as “near-threatened” globally. Unlike other some other carnivores in Panama, such as jaguar, puma and coyote, bush dogs do not appear to be directly persecuted by humans. The main threats are habitat loss and encroachment–15 percent of Panama’s forests were lost between 1990 and 2010. Bush dogs have very large home ranges for animals of their size, as much as 270 square miles, and they may require large tracts of forest to survive. Other threats include reduction of the abundance of their prey from hunting by humans and exposure to diseases carried by dogs used by hunters.
Cobia, a promising fish for aquaculture, lives throughout the world’s oceans except in the Central and Eastern Pacific. In August 2015, a large number of young fish escaped from offshore cages in Ecuador. Cobia have recently been reported from the Colombian and Panamanian Pacific coast, indicating their rapid spread from the release site. Voracious carnivores, cobia could have far-reaching impacts on fisheries and marine ecology in the Eastern Pacific, Smithsonian scientists warn.
“The havoc caused by invasive Indo-Pacific lionfish throughout the Caribbean provides a compelling lesson about the strong adverse effects that alien marine fish can have on naïve ecosystems,” said D. Ross Robertson, staff scientist at the Smithsonian Tropical Research Institute.
“The extraordinary success of the lionfish in the Caribbean is due in large part to its being a type of predator with no near relatives or ecological analogs among the Caribbean fish fauna,” Robertson said. “As cobia is the only species in its family, which is most closely related to remoras or shark-suckers, it too represents an unusual type of predator for the tropical East Pacific, which only increases both the degree of uncertainty about its effects and the potential for major disruption of the area’s ecosystems.”
Cobia (Rachycentron canadum) are streamlined in shape with nearly smooth skin, brown above and white below, with a darker brown stripe on the side. Young fish have strong horizontal dark brown and white stripes. They attain a maximum length of two meters (78 inches) and maximum weight of 78 kilograms (172 pounds). They eat crustaceans (especially crabs), squid and fish. Cobia are also known as black kingfish, black salmon (although they are not related), ling, crabeater and several other names.
The species is found in warmer waters on both sides of the Atlantic, and throughout the Indian and Western Pacific Oceans. Cobia occur both offshore and in coastal waters and estuaries and are highly migratory. Eggs and larvae float among plankton, making them capable of spreading widely.
Cobia are considered to be an excellent food fish, with firm texture and good flavor. Although the species is relatively uncommon in most of its natural range, it has high potential for aquaculture due to its hardiness and exceptionally fast growth. Cobia are now being cultivated in Taiwan, Vietnam, China, the Philippines, Indonesia, Belize, Brazil and on Panama’s Caribbean Coast.
Many introduced or non-native species have little or no adverse effect on local ecosystems. However, some become invasive and harm native species via predation, competition or other negative effects. Although examples of invasive species are common in land and freshwater habitats, until recently there were no documented cases in marine environments. In the early 1990s, Indo-Pacific lionfish (Pterois sp.) were introduced to the Florida/Bahamas area, and have since spread throughout much of the Western Atlantic and Caribbean. Rapacious predators on shrimp and fishes and protected from being eaten by venomous spines, lionfish have produced dramatic changes in coral reef communities in their new range.
Fishermen, marine resources agencies and marine ecologists should be aware that cobia are now present in the Eastern Pacific and the potential deleterious effects they may have. While it is not yet certain that they will become established, their broad environmental tolerance and rapid growth make this a distinct possibility. Catches or sightings (verified with photographs) of cobia in Pacific waters should be noted and reported to D. Ross Robertson email@example.com.
In the first volume of the Secret Smithsonian Adventures graphic-novel series from Smithsonian Books, The Wrong Wrights, four middle-school kids visit the Smithsonian’s National Air and Space Museum to find a completely different museum than the one they expected.
On a field trip to the museum, Dominique, Eric, Josephine and Ajay discover that all the airplanes and space ships are gone—in their place are balloons, blimps and dirigibles. Using their knowledge of science and history, the friends set out to solve the mystery of what is going on and who is at the bottom of it.
Al, a museum “fabrications specialist” at the museum leads them back in time to Manhattan’s Battery Park 1909 where early aviators are preparing to demonstrate their flying machines. A computer named “Smitty” (Smithsonian Archive Interface Facilitator) guides the group, and they meet-up with aviation pioneers Orville and Wilbur Wright, Glenn Curtiss and Thomas Scott Baldwin. They also meet Katharine Wright, Orville and Wilbur’s sister, who assisted her brothers with their experiments.
As the kids foil those who are trying to alter aviation history, they learn about aerodynamics and other aviation principles. Their work returns the Air and Space Museum to normal with its display of airplanes and space ships, and the Wright brothers’ place in history is restored.
This colorful book is written by Steve Hockensmith and Chris Kientz and illustrated by Lee Nielsen. Geared to 9-to-12-year-old readers and their parents, grandparents, teachers and librarians, The Wrong Wrights is the first graphic novel in a Smithsonian Book’s series that will include adventures set in the Smithsonian’s National Museum of Natural History (Claws and Effect) and the National Museum of American History.
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Hundreds of thousands of asteroids are known to orbit our Sun at distances ranging from near the Earth to beyond Saturn. The most widely known collection of asteroids, the “main belt,” contains some of the largest and brightest asteroids and lies between the orbits of Mars and Jupiter. Astronomers think that the asteroids, like the planets, formed in the early solar system from the gradual agglomeration of smaller particles but that, in the case of asteroids, their growth was interrupted by mutual collisions that caused them to fragment rather than to coalesce into planets. This is an hypothesis which astronomers are trying to test by gathering new data. Their work has some immediate repercussions: NASA is currently planning an “Asteroid Redirect Mission (ARM)” as part of America’s next human spaceflight enterprise. Understanding the origins of asteroid sizes – and then identifying a good one for an astronaut to recover – are prime US goals.
The discovery rate of asteroids and comets has increased in recent years thanks to new technology detectors. The Solar System today is seen as teeming with activity, and filled with related, evolving small bodies (including asteroids) whose orbits and sizes are shaped by gravitational interactions with the giant planets, but also by other forces like collisions and radiation effects. Radiation effects include the evaporation of water ice or other volatiles, differential thermal expansion, and radiation pressure — and they are critical when addressing the issue of asteroid sizes. Because asteroids are irregularly shaped, the pressure of incident sunlight and also effect of their own outward radiation (which is unevenly directed) can cause them to spin and, when the spinning is fast enough, to break-up.
A “catastrophic disruption” is defined as the breakup of an asteroid into fragments each smaller than half the original mass. Traditionally small asteroids have been thought to be made in collisions between a parent body and a smaller projectile body, but these events seem to be very rare, both from observations and newer modeling. Renewed attention has recently been given to non-collisional break-up mechanisms like radiation effects, especially for asteroids smaller than a few hundred meters in diameter.
CfA astronomer Tim Spahr and his colleagues have completed a new set of calculations for catastrophic disruptions of main belt asteroids, building on new survey results of faint (that is, probably small) asteroids. They find that for asteroids about one hundred meters in diameter collisions are not the primarily cause of break ups – rapid rotation is. Moreover, because the rate of collisions depends on the numbers and sizes of objects but rotation does not, their results are in strong disagreement with previous models of collisionally-produced small asteroids.
Reptiles have a rough exterior that make them seem like they don’t need a lot of very specific care. The reality is quite the opposite. Caretakers at Smithsonian’s National Zoo introduce us to some of the most charismatic reptiles in residence … and their particular grooming routines.
The majority of stars in our galaxy come in pairs. In particular, the most massive stars usually have a companion. These fraternal twins tend to be somewhat equal partners when it comes to mass – but not always. In a quest to find mismatched star pairs known as extreme mass-ratio binaries, astronomers have discovered a new class of binary stars. One star is fully formed while the other is still in its infancy.
“We caught them at just the right time. In effect, we’re seeing these stars in the delivery room,” says lead author Maxwell Moe of the Harvard-Smithsonian Center for Astrophysics (CfA).
The more massive a star is, the brighter it shines. This makes it difficult to identify extreme mass-ratio binaries because the heavier star outshines, and thereby hides, the lighter star.
To combat this effect Moe and his CfA colleague Rosanne DiStefano looked for eclipsing systems, in which the two stars line up in such a way that they periodically pass in front of each other as seen from Earth. When the fainter star eclipses the brighter star, their combined light drops detectably. These systems are rare because they require a precise alignment as seen from Earth.
After sifting through thousands of eclipsing systems, they identified 18 extreme mass-ratio binaries in a neighboring galaxy called the Large Magellanic Cloud. The stars circle each other tightly in orbits with periods of 3 to 9 days. The more massive stars weigh 6 to 16 times as much as the Sun, while the less massive stars weigh about 1 to 2 times the Sun.
A clue to the young nature of these systems came from an unusual feature in the data. The fainter star shows illumination phases, just like phases of the moon, as the two stars orbit each other. This indicates that the companion is reflecting the light of the brighter, more massive star.
We only see phases because the fainter and less massive companion is not yet a full-fledged star. Astronomers describe it as being “pre-main sequence.”
A star forms when a giant clump of gas pulls together under its own gravity, growing denser and hotter until nuclear fusion ignites. This process happens faster for more massive stars.
“Imagine if a human baby shrank as it got older instead of growing. That’s what happens for young stars,” says DiStefano.
In the young systems this research identified, the more massive star is already on the main sequence, while the less massive companion is not. As a result, that companion is puffier than it would be, since it is still contracting. This effectively lets the pre-main sequence star act as a giant mirror, reflecting the brilliance of its partner.
The discovery of these stellar twins could provide invaluable insight into the formation and evolution of massive stars, close binaries, and star nurseries.
These 18 systems were culled from millions of stars in the Large Magellanic Cloud observed by the Optical Gravitational Lensing Experiment. Due to their rarity, finding examples in our galaxy likely will require an extensive survey using facilities like the upcoming Large Synoptic Survey Telescope.
This research has been accepted for publication in The Astrophysical Journal.
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Caitlin Burrell, research scientist at the Smithsonian Conservation Biology Institute, returned from China last night April 20, with frozen giant panda semen that had been stored at the Bifengxia Giant Panda Base’s cryopreservation bank. The sperm may be used for an artificial insemination on the Zoo’s female giant panda Mei Xiang (may-SHONG) when she goes into estrus this spring. This is the first time frozen semen has been transported from China to the National Zoo for breeding.
The semen sample was collected from Hui Hui (h-WEI h-WEI). A cub sired by Hui Hui would be more genetically valuable than a cub sired by the National Zoo’s male Tian Tian (t-YEN t-YEN). Hui Hui lives at the China Research and Conservation Center for the Giant Panda in Wolong, Sichuan Province. He is 9 years old and has not yet sired any cubs.
The frozen semen was flown from Chengdu and kept frozen at minus 196 degrees Celsius in liquid nitrogen for the more than 7,000-mile journey. After landing at Dulles International Airport, the semen was taken to the SCBI’s cryopreservation bank at the National Zoo. The Zoo documented the trip on its @SmithsonianZoo Instagram account using #InstaScience and #PandaStory.
“This is the first time we have imported semen from China for panda breeding,” said Dennis Kelly, director of the Smithsonian’s National Zoo. “I want to thank everyone involved, including the U.S. Fish and Wildlife Service, China’s State Forestry Administration, and our own team of panda scientists, who made this transport possible.”
The National Zoo received the semen as the result of a breeding recommendation. Each year SCBI scientist Jon Ballou calculates the best genetic matches for all of the eligible breeding pandas around the world. He originally developed the mathematical formula used to make the recommendations in the 1990s for golden lion tamarins. It is now used to make breeding recommendations for all species managed by Species Survival Plans in human care. Scientists are working to preserve 90 percent of the genetic diversity of the giant pandas living in human care for the next 200 years. There are currently 392 giant pandas living in human care; scientists hope to grow the population to 500 bears.
The Zoo’s panda team expects that Mei Xiang will go into estrus for 24 to 72 hours this spring. Research shows that females usually go into estrus 45 to 50 days after they have weaned and separated from their cubs. The panda team slowly simulated that natural process for Mei Xiang and 20-month-old juvenile Bao Bao. They have been living separately since March 1.
Mei Xiang and Tian Tian have produced two surviving cubs while living at the National Zoo. Tai Shan, their first cub, was born July 9, 2005. He now lives in China. Bao Bao, their second cub, was born Aug. 23, 2013. She will leave the Zoo and travel to China when she turns 4 years old.
China’s State Forestry Administration released new giant panda census data in February; an estimated 1,864 giant pandas are now living in the wild. That is an increase of 16.8 percent since the last census, which found 1,600 pandas in the wild.
How soon after the Big Bang could water have existed? Not right away, because water molecules contain oxygen and oxygen had to be formed in the first stars. Then that oxygen had to disperse and unite with hydrogen in significant amounts. New theoretical work finds that despite these complications, water vapor could have been just as abundant in pockets of space a billion years after the Big Bang as it is today.
“We looked at the chemistry within young molecular clouds containing a thousand times less oxygen than our Sun. To our surprise, we found we can get as much water vapor as we see in our own galaxy,” says astrophysicist Avi Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA).
The early universe lacked elements heavier than hydrogen and helium. The first generation of stars are believed to have been massive and short-lived. Those stars generated elements like oxygen, which then spread outward via stellar winds and supernova explosions. This resulted in “islands” of gas enriched in heavy elements. Even these islands, however, were much poorer in oxygen than gas within the Milky Way today.
The team examined the chemical reactions that could lead to the formation of water within the oxygen-poor environment of early molecular clouds. They found that at temperatures around 80 degrees Fahrenheit (300 Kelvin), abundant water could form in the gas phase despite the relative lack of raw materials.
“These temperatures are likely because the universe then was warmer than today and the gas was unable to cool effectively,” explains lead author and PhD student Shmuel Bialy of Tel Aviv University.
“The glow of the cosmic microwave background was hotter, and gas densities were higher,” adds Amiel Sternberg, a co-author from Tel Aviv University.
Although ultraviolet light from stars would break apart water molecules, after hundreds of millions of years an equilibrium could be reached between water formation and destruction. The team found that equilibrium to be similar to levels of water vapor seen in the local universe.
“You can build up significant quantities of water in the gas phase even without much enrichment in heavy elements,” adds Bialy.
This current work calculates how much water could exist in the gas phase within molecular clouds that will form later generations of stars and planets. It doesn’t address how much water would exist in ice form (which dominates within our galaxy) or what fraction of all the water might actually be incorporated into newly forming planetary systems.
This work has been accepted for publication in the Astrophysical Journal Letters and is available online. The authors are Shmuel Bialy & Amiel Sternberg (Tel Aviv University) and Avi Loeb (CfA). This joint project was carried out as part of the Raymond and Beverly Sackler Tel Aviv University-Harvard Astronomy Program.
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For the first time, a team from the Smithsonian Conservation Biology Institute’s (SCBI) Center for Conservation Education and Sustainability collected photo evidence of an Andean bear (also known as the spectacled bear) in Peru’s Amarakaeri Comunal Reserve using camera traps—automated cameras with motion sensors. Three camera trapping locations within the Reserve documented the species between late February and early March 2015. The data collected from these cameras will help the Amarakaeri Comunal Reserve protect this culturally and ecologically important species. Andean bears are listed as vulnerable on the International Union for Conservation of Nature‘s Red List of Threatened Species. It is estimated that there are only 20,000 left in the wild due to threats including hunting and habitat loss from deforestation, mining, and road construction.
The team, including Tremaine Gregory and Hadrien Vanthomme from SCBI, Alejandro Portillo from the Universidad de Cusco, Peru, and Alcides Fernandez, from the local Yine community of Diamante, is conducting studies in the Southern Peruvian Amazon to understand changes in the distribution of large mammals over the course of the construction of a natural gas well. Since June 2014, researchers have recorded more than 25 mammals in the Reserve using camera traps.
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Geologic mapping is an integral part of exploration and understanding a planetary landscape, because it shows the relationships between geologic units and helps delineate the history of a surface. New orbiting spacecraft are obtaining data with progressively higher resolution, and as a consequence maps constantly need to be updated and improved. Read more from the National Air and Space Museum…
Pollinators like butterflies, bees, beetles, flies, and moths help to pollinate almost 80 percent of the world’s flowering plants, one benefit of which is providing food for humans. Because their daily activities have such beneficial consequences for all life, it is important to make sure pollinators have places to rest, feed and reproduce.
James Gagliardi, lead horticulturist with Smithsonian Gardens at the Smithsonian’s National Museum of Natural History, says that the museum’s Butterfly Habitat Garden is setting the example by offering a balanced ecosystem for these pollinators right in the middle of Washington, D.C.
“Our garden offers butterflies a place to stop, pollinate, lay their eggs and get the rest they need,” Gagliardi says, pointing to the garden as a great example of how the Smithsonian is complying with the recent memorandum from President Obama asking federal buildings to make a concerted effort to be more pollinator friendly.
The Smithsonian has been making an effort to help pollinator populations for years, and continues to focus on helping educate the public about what they can do in their own backyard to attract and help pollinators.
“When people step into our garden they aren’t just getting to see the butterflies. We offer wonderful education panels so the average homeowner can produce the same pollinator-friendly spaces in their own yard,” Gagliardi says of the upgrades being made to the Butterfly Habitat Garden in anticipation of its upcoming name change to the Pollinator Garden. “The garden has always functioned as a pollinator garden. Now with the broad emphasis on supporting all pollinators we want our garden to reflect that commitment” Gagliardi says.
Gagliardi’s top three tips for creating a pollinator-friendly garden:
The Smithsonian’s National Museum of Natural History announced today that scientists with the museum’s Global Genome Initiative will attempt to capture the genomic diversity of half the world’s living plant genera in the next two years. To start, GGI scientists and field teams from the museum’s Department of Botany have begun sampling plants in the holdings of Smithsonian Gardens, the U.S. Botanic Garden and the U.S. Department of Agriculture’s U.S. National Arboretum.
Tissue samples from these collections will be preserved by freezing in liquid nitrogen and then stored indefinitely in the Smithsonian’s biorepository at its Museum Support Center in Suitland, Md. A pressed specimen of each plant will be housed in the U.S. National Herbarium at the National Museum of Natural History. Scientists worldwide will be able to access the samples through the Global Genome Biodiversity Network’s data portal.
“This pilot collaborative effort between the Smithsonian, U.S. National Arboretum and the U.S. Botanic Garden comes at an urgent time when the scientific community’s access to the world’s plant genomes—the blueprint of life—is limited due to biodiversity loss and lackluster genomic-research infrastructure,” says Jonathan Coddington, director of the National Museum of Natural History’s Global Genome Initiative. Scientists have estimated that the recent rate of species extinction is faster than at any other time in recorded history, perhaps 100 times faster than normal.
The gardens in Washington, D.C. contain plants from around the world, culled from desert climates to lush tropical rainforests. Young and aspiring scientists will assist the sampling project as part of GGI’s commitment to train the next generation of genomic scientists.
“Now more than ever, the Smithsonian is dedicated to increasing our knowledge about life on Earth through emerging genomic technologies and capabilities,” said John Kress, the Smithsonian’s interim Under Secretary for Science. “Partnering with botanical gardens around the world is an essential step in opening new doors to the hidden benefits that can emerge from the world’s plant genomes.”
To read a blog about this effort click here.
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Researchers have discovered a black hole that grew much more quickly than its host galaxy. The discovery calls into question previous assumptions on the development of galaxies.
The black hole was originally discovered using NASA’s Hubble Space Telescope, and was then detected in the Sloan Digital Sky Survey and by ESA’s XMM-Newton and NASA’s Chandra X-ray Observatory.
Benny Trakhtenbrot, from ETH Zurich’s Institute for Astronomy, and an international team of astrophysicists, performed a follow-up observation of this black hole using the 10 meter Keck telescope in Hawaii and were surprised by the results. The data, collected with a new instrument, revealed a giant black hole in an otherwise normal, distant galaxy, called CID-947. Because its light had to travel a very long distance, the scientists were observing it at a period when the universe was less than two billion years old, just 14 percent of its current age (almost 14 billion years have passed since the Big Bang).
An analysis of the data collected in Hawaii revealed that the black hole in CID-947, with nearly 7 billion solar masses, is among the most massive black holes discovered up to now. What surprised researchers in particular was not the black hole’s record mass, but rather the galaxy’s mass. The result was so surprising that two of the astronomers, including Hyewon Suh from the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA, had to verify the galaxy mass independently. Both came to the same conclusion. The team reports its findings in the current issue of the scientific journal Science.
The distant young black hole observed by the team weighs about 10% of its host galaxy’s mass. In today’s local universe, black holes typically reach a mass of 0.2% to 0.5% of their host galaxy’s mass. That means this black hole grew much more efficiently than its galaxy – contradicting the models that predicted a hand-in-hand development. From the available Chandra data for this source, the researchers also concluded that the black hole had reached the end of its growth. However, other data suggests stars were still forming throughout the host galaxy. Contrary to previous assumptions, the energy and gas flow, propelled by the black hole, did not stop the creation of stars.
The galaxy could continue to grow in the future, but the relationship between the mass of the black hole and that of the stars would remain unusually large. The researchers believe that CID-947 could thus be a precursor of the most extreme, massive systems that we observe in today’s local universe, such as the galaxy NGC 1277 in the constellation of Perseus, some 220 million light years away from our Milky Way.
NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for the agency’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.
(Source: Chandra X-ray Center, Cambridge, Mass)