The Research Staff of the North Carolina Museum of Natural Sciences includes experts in a wide variety of scientific disciplines who conduct exciting research investigations, maintain and expand the Museum’s natural science Research Collections, and participate in the Museum’s public education and outreach mission. Check this blog often to learn about all of the great science happening at the Museum!
This year’s Independence Day holiday was a special one for planetary science, as the NASA spacecraft Juno successfully entered the dense atmosphere of our solar system’s giant, Jupiter, yesterday at 11:53 PM, EDT. After 5 years and traveling nearly 550 million miles, Juno reached Jupiter at nearly 130,000 miles per hour, poised to orbit the planet 32 times, gathering unprecedented data on Jupiter’s atmosphere, magnetic, and gravitational fields, all lending clues to how it formed about 4.57 billion years ago.
Scientists think that Jupiter may have been the first planet to form from the swirling disk of gas and dust from which the rest of the solar system formed. Juno’s science will help unravel the detailed composition of Jupiter’s atmosphere which hold clues to its formation history, including how and where it formed relative to Earth and the Sun.
Unlike Earth and the other terrestrial planets, Venus and Mars, Jupiter is a “gas giant,” composed mostly of Hydrogen and Helium, and may have a rocky core. Juno will closely examine the rollicking storms in Jupiter’s clouds, including its mysterious Great Red Spot that has been shrinking over the several centuries since its discovery.
Jupiter’s largest moons, Io, Europa, Ganymede and Callisto, were discovered by Galileo in 1610, and imaged in detail first by the Voyager mission — twin probes launched in 1977 and now heading to interstellar space — followed by the Galileo flyby in 1995.
Juno will study Jupiter’s atmosphere and (possible) core in unprecedented detail, hopefully unraveling many of the mysteries surrounding fundamental processes during solar system formation, including that of planet Earth. As an observational astronomer interested in the earliest chemical pathways of planet formation, I am particularly eager to learn what Juno uncovers in the depths of Jupiter’s primitive, roiling atmosphere.
Here you can watch Juno approach Jupiter and the Galilean moons in this time-lapse capture by one of Juno’s imagers:
The mission will end in 2018 with Juno taking a nosedive into Jupiter’s atmosphere in a planned maneuver of final demise, similar to previous mission terminations.
In the meantime, we will stay tuned for Juno’s exciting new discoveries! You can watch the NASA’s Juno mission trailer for a brief yet informative and entertaining overview of the exciting science to come!
This summer, I joined a team of scientists and university students participating in a long-term study of the biodiversity of the Iwokrama Forest, a sustainable-use reserve covering almost one million acres in central Guyana. Iwokrama’s mission is to develop novel strategies to preserve biodiversity while also earning income from the forest, thereby demonstrating that it is possible to preserve functional ecosystems in the course of economic development.
I capture and band birds on study plots that I resample year after year to assess changes in species composition and abundance, and the age structure of populations. I also monitor avian diversity using automated sound recorders to document species at each site. The Iwokrama Forest boasts an impressive bird list – almost 500 species have been observed in the reserve!
Here I highlight some of the most interesting birds we captured this summer.
Antbirds are one of the most diverse bird families at Iwokrama, and we catch many in our nets. Students often ask me if they are called antbirds because they eat ants. The truth is much more interesting! Several species of antbirds are obligate army-ant followers. Army ants are common in rainforests of Central and South America, where they form large swarms that move across the forest floor, exploring every nook and crevice for prey.
No animal is safe from the ants – and as they attempt to flee, many are devoured by antbirds such as this Rufous-throated Antbird, one of two species of obligate army-ant followers at Iwokrama. These birds spend their entire day in the company of army ants, and their churring calls are a sure indicator that an ant swarm is nearby.
It is fascinating to watch these birds dart back and forth over the ants, clinging to vertical saplings with their powerful feet, snapping up insects as they try frantically to escape.
Although rainforests may look homogeneous, they are very complex places where many species coexist, often by specializing on particular resources.
The Black-chinned Antbird occurs only in a flooded forest, where it forages for insects in dense tangles along rivers and creeks. This specialization allows it to live in close proximity to other, ecologically similar species.
Within a single patch of rainforest, there can be several different vegetation types. One of the most common of these is seasonally flooded forest. During the annual rainy seasons at Iwokrama, the Essequibo River swells into the surrounding floodplain, bringing nutrients into the forest and influencing its structure and plant species composition.
Manakins are one of the most abundant birds in the forest understory at Iwokrama. This dazzling adult male White-crowned Manakin looks very different from his younger counterparts, which are clad in dull gray and green, resembling the females. Manakins are frugivores – their diet is almost entirely fruit – which means that they are constantly moving through the understory from one food source to the next, and this is why we catch so many of them in our nets.
Aside from eating, the most important activity in a male manakin’s day is displaying for females! Since fruit requires little effort to “hunt”, these birds can fill up fast and spend the rest of the day on their display perches, or leks.
Competition is fierce, and the end result is that the manakins include among their ranks some of the most beautiful plumages and complex displays in the bird world. This adult male – whose black body plumage still has a speck of green from his younger days – will glow iridescent blue on his display perch in the middle levels of the forest.
Here is one of the more bizarre birds we catch. The puffbirds are distantly related to kingfishers and resemble them in certain respects – both have large heads, oversized bills, and small feet, and both nest in cavities. But rather than hunting for fish along rivers and creeks, as kingfishers do, puffbirds are solitary predators of the forest, sitting still for long periods of time and darting out for large insects and small vertebrates such as lizards, frogs, and snakes. They spend so much time sitting still that they can easily be overlooked, and seeing one in the hand is a treat.
Puffbirds are named for their soft, lax plumage, and they often fluff themselves and open their bill when handled, as this one is doing.
The function of the curious notch on the tip of the bill is unknown – it could help them hold onto struggling prey, or perhaps it is used as a tool to dig their nest burrows, which are often in arboreal termite nests.
This bird puts on a show like no other – behold the Royal Flycatcher, an outlandish member of the most diverse bird family in the Neotropics, the Tyrannidae or Tyrant-Flycatchers. Although we catch relatively few species of flycatchers in forest understory at Iwokrama, this is the one we always hope to find in our nets! The spectacular crest is usually held flat along the top of the head, its colors subdued.
But when caught in a mist net, the Royal Flycatcher becomes a different beast entirely, as you can see here. The bird contorts itself, constantly turning its head almost completely upside down and from side to side, in a mesmerizing performance that will last for as long as it is handled.
Although the display is thought to be used in territorial encounters, few people have seen it in free-flying birds, since this species normally lives quietly in pairs along creeks and forest edges, where it is rather difficult to see. Royal Flycatcher nests are distinctive hanging structures, sometimes up to one meter long, usually placed over stream beds or narrow roads in the forest.
Many thanks to the staff of the Iwokrama Centre for Rainforest Conservation and Development, EPA-Guyana, the village of Surama, and to Operation Wallacea, for their support of my research.
Summer is here, it’s hot, the kids are out of school, and by now I expect they’re pretty bored. Perhaps it’s time to go outside and see how bored other things are. For instance, if you’re at the beach, you might find a clam shell with a perfectly circular hole in it. That’s a bored clam shell. Or maybe you’re lucky enough to find a rock or coral with some broad holes in it. Or maybe you notice holes in trees or logs. These are all bored, too.
But what causes all these objects to be so bored? In the case of the shell at the beach, the answer is predatory snails. Some snails – particularly moon snails – soften a clam’s shell by using a boring organ that produces hydrochloric acid, enzymes and other substances. Then the snail rasps the softened clam shell with a hard plate called a radula, resulting in a circular hole. If you look closely at it, you’ll see the hole is wider on the outside than on the inside of the shell. Once the snail breaks through the shell, the snail uses its radula to rasp away the clam’s soft tissues, basically eating the clam alive. Now that’s both boring and exciting!
Broad holes that you might find in rocks or coral are made by boring clams. (This means you can be as happy as a clam or as boring as a clam.) Certain clams, such as angel wings, piddocks or pholad clams, use the rough edges of their shells like files to slowly grind against rocks or corals, twisting themselves in. These clams rotate into rock at a rate of 4 or 5 centimeters (about 2 inches) per year, which is slower than your fingernails grow. Most boring clams stop when they’ve bored a hole the length of their bodies, but some drill themselves several body-lengths deep over the course of their lives. These clams eat by extending tubes called siphons (much like a vacuum-cleaner hose), to filter feed on passing plankton. But once they’ve lodged themselves in a coral or rock, they don’t leave. They’ve literally dug their own graves.
Not only are some snails and clams boring, but certain insects are boring too. Got holes in your floor, wood siding or in the dead tree in your yard? These are likely the result of wood-boring beetles, termites, carpenter ants or carpenter bees. Even non-insect arthropods, such as some isopods (think “roly-poly pillbugs”), can bore into wood. Whatever animal is eating into your wood, you can bet it is boring.
So, let’s say I’m a paleontologist (which I am). I may not find remains of the actual animal that made holes in fossil shells or petrified wood. But by studying the shape of the hole, the bored substratum, and by knowing a little bit about different animals’ behaviors, I can deduce what animal might have been boring. Ichnology, the study of traces, can be a lot like forensic detective investigation. To me, that’s not boring, that’s fascinating.
Reprinted from The Charlotte Observer and Raleigh News & Observer
As temperatures creep toward the triple digits this week, it’s probably not hard to remember that the Sun is our primary source for heat and light. Perhaps less obvious is that the Sun is also responsible for space weather, defined as the varying conditions surrounding the Earth that are due to solar wind and other energetic outbursts from the Sun’s surface. While there is no conclusive linkage between space weather and Earth’s climate, solar particles penetrating Earth’s magnetic field risk disrupting performance and reliability of space-borne and ground-based technological systems, satellites, and even possibly endangering life. One of the main objectives of space missions currently studying the Sun is to better understand extreme space weather events, how and when they occur, and how life on Earth may be affected, now and in the future.
STEREO (Solar Terrestrial Relations Observatory) has revolutionized the study of the Sun-Earth system. Consisting of two nearly identical observatories, one ahead and one behind Earth in its orbit of the Sun, STEREO traces the flow of energy and matter from the Sun to the Earth, revealing 3-dimensional structures of violent eruptions coming off the Sun’s surface. If directed toward Earth, these eruptions, called coronal mass ejections (or CMEs), can trigger severe magnetic storms when they collide with Earth’s magnetic field, disrupting satellites and power grids. CMEs are also extremely hazardous to astronauts on the International Space Station and performing Extra Vehicular Activities. Studying these violent solar storms in detail helps scientists understand their fundamental nature and origin, and the extent to which they can affect life on Earth.
Computer models of superstorms such as the one of 2012, shown above, have helped scientists better understand and predict the onset of storms that could be directed at Earth. By matching their models to past observations, solar astronomers have found that it is not only the origin of CMEs at the Sun’s surface, but also the interactions between successive CMEs farther out in interplanetary space that contribute to extreme space weather events. The Solar Dynamics Observatory (SDO) is another satellite mission taking unprecedented images of the Sun, showing its surface features, storms and flares in great detail, enabling the study of solar prominences and energetic outbursts that regularly spew into space. Orbiting the Earth at nearly 7000 miles per hour, SDO has captured the most detailed imagery of the Sun to date, revealing its surface in amazing fiery and dynamic detail. The image below shows a dark region called a coronal hole in the surface of the Sun, an area where high-speed solar wind particles stream into space.
Solar flares are sudden flashes of brightness from the Sun’s surface, linked to great releases of energy, often occurring just prior to CMEs. Such bright regions can be seen in many SDO images, including the one below, which also shows loops of superheated plasma seen extending off the surface; these loops can’t escape the magnetic filed of the Sun but rather follow the field lines back to the surface.
Solar flares strongly influence space weather near Earth, producing streams of energetic particles in the solar wind. When solar wind particles impact the Earth’s magnetic field, they can generate a geomagnetic storm which presents radiation hazards to satellites and humans on Earth and in space. To generate some of the remarkable imagery and videos for scientists and astronomy enthusiasts, SDO’s instruments capture images of the Sun at frequent intervals, showing how the surface changes rapidly. The gorgeous composite below was made from 25 separate images taken at extreme ultraviolet wavelengths, which enable viewing very high temperature solar material.You can see the Sun changing over the course of 3 years in this video. Because the distance between the SDO spacecraft and the Sun varies over time, the apparent size of the Sun subtly increases and decreases over time in the video. What does extreme space weather mean for our future? Aside from immediate power grid and satellite concerns, short-term radiation risks posed by solar flares are being considering in current planning stages for sending humans to Mars, the Moon, and even other planets. Energetic protons passing through the human body can cause serious biochemical damage, harming astronauts not only during interplanetary travel but also once they arrive at their destination. In the very far future, the Sun will become a red giant and engulf the Earth; but not to worry, as this won’t happen for another 5 billion years or so. In the meantime, scientists are studying space weather and extreme solar events that can affect life on our planet in order to be better prepared for living with our star. This information is further useful for understanding how stars affect life on planets beyond our solar system, some of which may ultimately be the future home for our species long after the Sun is gone. For more amazing solar footage, play the video compilation of SDO’s “best video imagery” from the last 5 years, below:
Want to learn more about the Sun, extreme space weather, and solar missions, and view its surface safely through solar telescopes? Join us for International SUNday (and the first day of summer!) this Sunday, June 21, for special presentations and solar viewing (weather permitting). More details on International SUNday can be found here.
The little space-bot, Philae, made history last November by being the first-ever robot to land on a comet. While amazing in its technological feats and detailed measurements of comet 67P taken at close range, all was not perfect with this historic landing, leading European Space Agency (ESA) scientists to admit that, shortly after landing they did not in fact know Philae’s location on the comet.
The glitch was a misfire of Philae’s landing harpoons such that the robot bounced off the comet twice, eventually becoming wedged in one of the comet’s cliffs, the precise location of which, the scientists admitted, was unknown.
Due to the non-sticky landing, the final orientation of Philae’s solar panels were such that it was unable to capture enough sunlight to power its instruments. Yet, not to be undone, mission scientists completed nearly all of the robot’s science goals atop the comet within the 60 hours of the lander’s battery life. Further, through the brief contact window, mission engineers were able to rotate the Philae’s solar panels in such a way that, just possibly, Philae might capture enough sunlight to “reawaken” and continue its groundbreaking science as comet 67P neared the inner solar system, thought to be sometime during the summer of 2015.
Now, Philae has made history again. To great excitement, the little robot has awakened from its long hibernation, with the news revealed via ESA mission Tweet:
Rosetta mission scientists today stated that Philae is doing quite well, communicating with the ground team for 85 seconds. With an operating temperature of -35ºC (-31ºF), it has acquired enough sunlight to power operations so that it may continue exploring the cometary molecules that are the primitive leftovers from solar system formation. Studying these molecules will give scientists clues as to how our solar system, and possibly life, formed and evolved.
Rosetta scientists analyzing the new data think that Philae may actually have been awake even earlier than today. They now await next contact so that the 8000 data packets in the robot’s memory can be analyzed, hopefully revealing clues as to what new information Philae gathered in the past few days of mysterious operations.
Fans of this mission may recall Professor Monica Grady’s sheer joy on landing day, November 12, 2014, a reminder of the true passion scientists have for their work:
If you think that reaction was atypical, Dr. Grady revealed today that, upon hearing Philae’s news while in a taxi, she was so excited she hugged the driver. Congratulations, Philae, your team, and all who root for you!
Jupiter: giant planetary overlord of our solar system. From Earth, Jupiter’s gargantuan presence is hardly evident on a daily basis; to us it is a far-away dot in the night sky (albeit the third-brightest after the Moon and Venus).
But, Jupiter is special and significant. With a mass equal to 2.5 times that of all the other planets combined, it is by far the largest planet in the solar system. Light from Jupiter can be bright enough to cast shadows on Earth, which is impressive given that its average distance from us hovers between ~ 460 million and 510 million miles. And, while it is the great giant of our planets, Jupiter is made up primarily of the lightest of gases: hydrogen (primarily) and helium. While it may have a rocky core, it has no solid surface to speak of, rendering it most difficult to imagine as either a haven for extraterrestrial life, or a destination for futuristic human space travelers.Due to its large mass and consequently strong gravitational pull, Jupiter acts as a “cosmic vacuum cleaner,” protecting Earth from being pelted with many more asteroids and comets than have reached the surface throughout its history. The impact rate on Jupiter has been estimated to be between two- and eight- thousand times greater than Earth, and without Jupiter it is hypothesized that life on Earth may not have made it this far. In fact, scientists think that habitability on any Earth-like planet — in exoplanetary systems in the Galaxy — may in part depend on a nearby Jupiter-like giant that attracts a large percentage of space debris.
As recently as the 1990s, Jupiter has shown it can do the job. In 1992, astronomers witnessed the break up of comet Shoemaker-Levy 9, torn apart by Jupiter’s gravitational forces, leading to it being described as a “string of pearls”:In 1994, the comet’s 21 discernible fragments, with diameters up to 2 km (~ 1.2 miles), collided with Jupiter at speeds exceeding 130,000 miles per hour. If even one of those fragments had reached a populated region of Earth, the result would likely have been more than just a cosmic light show.
In addition to their physical grandeur, Jupiter and its four most prominent moons — Io, Europa, Io, Ganymede, and Callisto (see the image montage, above) — figure prominently in the evolution of our understanding of the solar system. Now aptly referred to as the “Galilean Satellites”, these four moons were discovered by Galileo Galilei in 1610, marking one of the most significant contributions to science. Galileo used a homemade telescope to make these observations which helped him prove that, without doubt, the Sun, not the Earth (as thought at the time), was the center of the solar system.
Galileo Galilei is often referred to as “the father of modern observational astronomy” for his work on the Jupiter system, the phases of Venus, and sunspots, and he laid the foundation for today’s modern space probes and telescopes. In the more than 400 years since, we’ve certainly come a long way technologically. Data and images from the Voyager and Galileo missions to Jupiter and the outer planets have revealed incredible details of these foreign worlds. The year 2012 marked the 35th Anniversary of Voyager, now in interstellar space, making it the farthest spacecraft ever launched from Earth.
While our record of state-of-the-art space exploration is, rightfully, marked by missions backed by multinational consortia of space agencies and years of development, it should also be remembered developments in technology now give us hand-held devices that can help put astronomy at your fingertips.
I was recently involved in a public observing night, led by my colleague Professor Daniel Caton, at Appalachian State University’s Dark Sky Observatory in the mountains of Boone. It was a wonderfully clear night, during which we got a wonderful glimpse of the Geminid meteor shower. At one point, Jupiter and its four sparkling moons were put into view through the Observatory’s excellent 32-inch telescope. After the crowd dispersed I took a few minutes to fiddle with aligning my iPhone just so, and captured the image below:
I’ll stay tuned for a device one can whip out to capture 200x magnification of the celestial object of their choice — an “iTelescope”, if you will. For now, I like knowing that it’s not that hard to take a pretty decent image of a far-away system through the eyepiece of a moderately sized telescope, just with an iPhone. And now I have Jupiter in my pocket.
One of the comments on the earlier blog post came from Richard Jacquot:
firstname.lastname@example.org commented …In an article published with Ed Speer in Volume 1, Issue 2 of American Rockhound magazine in June, 2014, we discussed 15 diamonds that were found in Reedy Creek in Mecklenburg County. These diamonds were found by a gold prospector and sold to a reputable local mineral dealer. They were then sold to various collectors. This was around 1999. The diamonds averaged .5 carat and 1-2mm. The diamonds have been tested and there is no reason not to believe that the prospector found these, in fact, the story is very similar to this one. So what is the criteria for getting them authenticated?
To bring everyone else up to speed, Richard is publisher, editor, and in this case, also a writer for American Rockhound magazine. American Rockhound is a new addition to the world of magazines, so the distribution is not yet large, but I wish him and his co-authors much success. Goodness grows in North Carolina, and that includes the minerals.
As with any scientific question, the question finally revolves around who has the data, and what data do we (I) have in hand? I wasn’t able to get hold of a copy of the article, so I can’t speak to any of the particulars of that diamond find and sale. I don’t know any of the people involved, so I can’t really make a meaningful comment on that, either. I don’t have any evidence one way or the other. I do know about this diamond find, so I’ll go with what I know. Here’s how I approach the problem.
“Authenticate” covers a lot of territory. It’s not like these are antiques. I knew with about 95% certainty that these were diamonds from the moment I opened the package. The next step was to collect data to support that identification. Diamonds are isotropic on my petrographic scope- that is, in cross polarized light, they stay dark. Second was to look at the composition: EDS. With the great big carbon peak, there wasn’t much doubt.
The next question was natural vs. synthetic. For that I needed the assistance of a genuine diamond expert, and Diamonds Direct Crabtree came to the rescue. The verdict from the Gemological Institute of America was that the diamonds are natural.
The final step is like any other scientific study: reproduction of results. Could we reproduce Jeff’s findings, and then find the source of the diamonds? We were still working at that when Jeff died.
Rockhounds in the field tend to be very focused on what they want. I’m not a rockhound, I’m a research scientist. Rockhounds and other amateur geologists tend to be surprised at what I want, which is everything. A prospector may find gold in quartz veins, but then he’s surprised that I want the quartz, and the sulfide minerals. These minerals contain oxygen, hydrogen and sulfur isotopes that illuminate the origins of the gold-bearing fluid. Size is not an issue for analysis. The quartz usually contains fluid inclusions, fossil water that can be used to determine the temperature at which the veins formed. I want to know the relationships between the minerals and the gold, who’s first, who’s second, etc. Minerals are information to me.
Anyone discovering diamonds has a choice about what to do with that information. Do they withhold it, so they have monopoly on the sources? Good business sense, but not good scientific sense. Jeff shared data, and we got started on finding the source rocks. The burden of proof that these were North Carolina diamonds was clearly on him, and he was cooperative and helpful in working on the problem. I analyzed the other minerals that were panned with the diamonds, using the petrographic microscope and the SEM/EDS. We made thin sections of possible candidates for the source rock. I was confident enough to make the recent announcement, but prudent enough to keep working on the problem. A quick check of my birth certificate shows that I wasn’t born yesterday.
I don’t think so much about “authentication” as much as I do about “reproducing results.” Science is a good discipline for separating out what you know, what you can surmise, and what you don’t know, and for building multiple working hypotheses to test along the way. I have the diamonds, I have some of the minerals from the streams. I have several working hypotheses about source rocks to target.
I can understand skepticism about the discovery of the diamonds. Even if we had TV cameras on Jeff as he found them, there would still be suspicion about the sediments being salted, or even that the diamonds were purchased somewhere else. If we can reproduce Jeff’s results that would be strong support that these diamonds are from North Carolina. Finding the source would certainly clinch the question.
Astute readers will notice that I have been very vague about location of this discovery. True. I have a responsibility as an employee of the state of North Carolina to preserve a good relationship with land owners. Field guides to collecting minerals or fossils in North Carolina tend to result sites being destroyed or placed off limits to collection. Most collectors in the state are very careful and responsible, but it only takes one bad one to ruin things for everybody.
Early next year, we will be crowdfunding the costs of the research. The work has several lines of inquiry: (1) identification of the inclusions in the diamonds; (2) field work to obtain more samples of heavy minerals from the streams; and (3) microanalysis of mineral separates taken from the streams.
Stay tuned. Next blog up, multiple working hypotheses and geological research.