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Bringing Research to Light

February 18, 2011

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!

Part II- Ten New Diamonds from NC

December 9, 2014
This octahedral diamond cyrstal looks like it has been faceted. These are all growth textures on the triangular crystal faces. Also, this is my favorite picture.

This octahedral diamond cyrstal looks like it has been faceted. These are all growth textures on the triangular crystal faces. Also, this is my favorite picture.

One of the comments on the earlier blog post came from Richard Jacquot:

rick@wncrocks.com 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.

Ten New North Carolina Diamonds

December 4, 2014
This octahedral diamond cyrstal looks like it has been faceted. These are all growth textures on the triangular crystal faces.

NCSM 5997. This octahedral diamond crystal looks like it has been faceted. These are all natural growth textures on the triangular crystal faces.

There have been 13 diamonds found in the state of North Carolina since 1893, the largest of which was four carats. Most of them were found as a result of panning operations for gold or monazite. One of these is in the Geology Collection of the Museum of Natural Sciences: NCSM 3225. It came from Burke County and was part of the collection of J.A.D. Stephenson, the man who discovered emeralds and chromian spodumene (aka hiddenite) in Alexander County.

NCSM 3225, one of the original thirteeen diamonds found in North Carolina. From the collection of J.A.D Stephenson.

NCSM 3225, one of the original thirteeen diamonds found in North Carolina. From the collection of J.A.D Stephenson.

You can imagine my feelings when 13 more diamonds came into my laboratory, all at one time.

In many ways this story belongs to Jeff Moyer of Mount Pleasant, North Carolina, a gold prospector and amateur exploration geologist. Jeff was the most gifted amateur geologist I ever met. He was a keen student of history, consulting records from the old Charlotte Mint and taking time to learn the oral history of the areas where he worked. He designed and patented his own equipment. Our conversations about North Carolina geology were long and detailed, like I was having a thesis defense all over again. His restless and curious intellect eventually became fascinated with the idea of finding the source of North Carolina’s diamonds. So he modified his equipment to trap diamonds as well as gold. And it worked.

I have met all sorts of miners over the years, and Jeff impressed me as genuine. We purchased 10 of the diamonds, and I went to work. Jeff and I made plans to go into the field to reproduce his findings. It never happened. Jeff was diagnosed with Stage 4 lung cancer, and died shortly thereafter.

My instinct was that Jeff was honest, and not trying to put anything over on me and the Museum. But there is always the nagging suspicion that diamonds could be synthetic and not natural. Perhaps someone was salting Jeff’s area as a joke. We needed independent verification of the diamonds. I did everything I could. EDS analysis on the scanning electron microprobe at the Analytical Instrumentation Facility at NC State showed that they were diamonds with traces of iron, silicon and aluminum on the surface, consistent with a natural origin. The diamonds were also a variety of crystal shapes. Synthetic stones tend to be all of one crystal shape.

My own scientific expertise is in mineralogy, particularly thermodynamics and microanalysis. Minerals tell the entire story of the rock, but in this case, I couldn’t read it. The processes of making synthetic diamonds can be shrouded in secrecy, and the engineering moves faster than I can keep track of it. I needed an expert in diamonds, someone conversant in the ways to tell synthetic stones from natural stones. And there the project sat for many years. The Museum did not have the money to send the samples out for independent evaluation.

Fortunately for me, our new Director, Emlyn Koster, took an interest in the project. His commute every day took him past Diamonds Direct Crabtree, a North Carolina based diamond firm. They were diamond experts, why don’t we approach them?  <Facepalm> Why didn’t I think of that?

The Vice President of Diamonds Direct Crabtree, Mr. Barak Henis, took a personal interest in the diamonds. Diamonds Direct has an ongoing relationship with the Gemological Institute of America, so they sponsored the Museum by sending five of the diamonds for evaluation. They saved us a great deal of money.

The verdict came back: the stones were natural diamond. The people at Diamonds Direct Crabtree were as excited as we were.

So, dear readers, the Museum of Natural Sciences, Diamonds Direct Crabtree, and I are pleased to announce the discovery of 10 new diamonds from North Carolina.  This is exciting news for everyone. These diamonds are small, but it means we are one step closer to finding the source of diamonds in North Carolina. It also means that there is a scientific treasure trove waiting to tell us about the mantle far below North Carolina. I’ll take a look at that in later blog posts.

It also means we are one step closer to fulfilling Jeff Moyer’s legacy. Rest in peace, Jeff. You were right.

All ten new NC diamonds, on a millimeter grid for scale.

All ten new NC diamonds, on a millimeter grid for scale.

Pictures shown below were taken with the new Keyance Digital Microscope, purchased for Research and Collections thanks to a bequest from the estate of Renaldo Kuhler.  

NCSM5994.

NCSM5994.

NCSM 5995.

NCSM 5995.

NCSM 5996, a dodecahedral diamond crystal.

NCSM 5996, a dodecahedral diamond crystal.

NCSM 5997, a modified octahedron.

NCSM 5997, a modified octahedron.

NCSM 5998

NCSM 5998.

NCSM 5999. This is a perfect octahedron,

NCSM 5999. This is a perfect octahedron.

NCSM 6000.

NCSM 6000.

NCSM 6001.

NCSM 6001.

NCSM 6002.

NCSM 6002.

NCSM 6003.

NCSM 6003.

Conserving Asian newts could save the world’s salamanders

December 3, 2014

By Dr. Jodi Rowley, Dr. Bryan Stuart

Hong Kong Newt (Paramesotriton hongkongensis), Hong Kong. Copyright Dr. Jodi J L Rowley.

Hong Kong Newt (Paramesotriton hongkongensis), Hong Kong. Copyright Jodi J L Rowley.

Salamanders are popular as pets in many countries. To satisfy this demand, they are harvested from the wild and transported across the planet. But moving animals around the world also moves their parasites and pathogens. Recently, a newly discovered species of chytrid fungus appears to have hitchhiked to Europe on the skin of imported pet Asian salamanders of the family Salamandridae (‘newts’). Researchers have determined that Asian newts have co-existed with this fungus for perhaps 30 million years, and during that time evolved some protection from it. Unfortunately, laboratory experiments have shown that the fungus can be deadly to salamanders that have never been exposed to it, elsewhere in the world (more).

Scientists have rightly recommended that the international trade of live salamanders be more tightly controlled to prevent the spread of this fungal pathogen into European and North American salamander populations. But the plight of the Asian newts, which are threatened by overharvesting for the same pet trade, has received little attention. Controlling the global trade of live salamanders is vital to ensuring the survival of the Asian newts, too.

The tailed amphibians, or salamanders, are beautiful and usually gentle creatures, so it’s not surprising that people enjoy keeping them in terraria and aquaria as pets. However, to supply the pet trade, wild salamanders are collected from around the world, especially the rainforests of Central America and the cool, mountain streams of Asia.

A recent paper reported that a newly discovered amphibian chytrid fungus Batrachochytrium salamandrivorans (Bs) likely originated in Asia and hitchhiked to Europe on the skin of wild Asian newts imported to supply the pet trade.

The paper raised alarm that Bs now poses a threat to wild populations of European and North American salamanders. Already wild salamander populations in Europe appear to be declining. While this paper rightly sparked global alarm for the future of European and North American salamanders, the conservation crisis facing Asian newts themselves has not received enough attention.

More than one-third of all species of Southeast and East Asian newts are at risk of extinction, many due to overharvesting for the international pet trade. The Lao Newt (Laotriton laoensis) is an unusual, colorful species that lives only in a small part of northern Laos, and outside of any the country’s protected areas (more).

Shortly after the species was discovered and described to science in 2002, commercial collectors from Germany and Japan visited villages in Laos to obtain these rare newts for sale into the pet trade back at home (more). The government of Laos has since passed legislation banning the commercial trade of the newts in Laos, but unfortunately, illegal trade continues today. Many of the people who live near the Lao Newt are poor and unable to resist the money offered to them by illegal collectors, who then re-sell the newts to pet markets in Europe, Japan and the United States. Sadly, the Lao Newt is now Endangered in the wild, primarily due to illegal harvesting for the international pet trade.

Despite their protection in Laos, little can be done to stop the transportation and sale of Lao Newts once they leave the country, destined for the pet trade abroad. For example, no Asian newt species are currently listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), an international agreement that is intended to protect certain species from overexploitation.

The discovery of the origin of Bs presents a renewed opportunity to curb the sale of live Asian newts around the world. Lao Newts have not yet been tested for Bs, but the fungus has been in three other, very closely related species of Asian newts, and the Lao Newt probably carries it. Controlling the trade of live Asian newts will prevent European and North American salamanders from being further exposed to this fungal pathogen- and will also keep Asian newts safe in the wild.

Fortunately, some countries, including Australia, do not allow importing salamanders as pets. Other countries should follow suit to protect wild salamanders. In the meantime, many Asian newt species should be listed in the CITES convention. And countries around the world need to control the importation of live Asian newts as seriously as they do live poultry and livestock that also pose disease risks to domestic populations. Western and Asian countries should work together to curb the trade of live Asian newts. Doing so will keep Asian newts in the wild and the Western salamanders fungus-free. Otherwise, a global catastrophe to our world’s salamanders awaits.

Dr Jodi Rowley
Australian Museum Research Institute

Dr Bryan Stuart
North Carolina Museum of Natural Sciences

More information:
Stuart, B. L., Rowley, J.J.L., Phimmachak, S., Aowphol, A. & Sivongxay, N. (2014). Salamander protection starts with the newt.Science 346 (6213): 1067-1068.

Mars, Rainbow Planet

November 22, 2014

In fact, Mars is still our solar system’s beloved “Red Planet”, so-named for the abundance of iron oxide on its surface. And if held in your hand, Mars rocks most Mars rocks will appear rather similar to rocks from our home planet. However, also like rocks from Earth and other planetary bodies, very thin slices, or thin sections, of Martian terrain will look brilliantly colored using polarized light microscopy, a method that depends on how light bends through materials with varying optical properties, and used in identifying crystals and minerals .

We recently started imaging a new set of Martian and other extraterrestrial samples in the Astronomy & Astrophysics Research Lab, beginning with Martian rocks, shown below in brilliant color.

But first, how can we have samples of Mars, since we’ve never had a mission return with any rocks? The answer: meteorites. Out of more than 61,000 meteorites found on Earth, 132 are thought to be from Mars. Their origin is deduced primarily from their unique relative composition of trapped gases (Mars’ atmosphere is nearly 96% carbon dioxide, with nearly 2% each argon and nitrogen, and less than 1% oxygen and carbon monoxide), which we know to great accuracy from our missions to Mars. Some time in the past, these future meteorites were blasted off the surface of Mars from the impact of a large body, most likely an asteroid, then traveled in space for thousands, even millions of years, before reaching Earth.

Compare the two images below. The  first shows the thin section from the Martian meteorite, Tissint, seen with our unaided eye. The second image below shows Tissint in polarized light, revealing the large olivine minerals which are colored due to the way the light bends as it passes through the complex crystalline structures.

Thin section of the Martian meteorite, Tissint, as seen with the unaided eye (Image credit: Anna Morris, Astronomy & Astrophysics Research Lab, NCMNS).

Thin section of the Martian meteorite, Tissint, as seen with the unaided eye (Image credit: Anna Morris, Astronomy & Astrophysics Research Lab, NCMNS).

TissintPano-sm-framed copy

Tissint thin section as seen in polarized light, in the 1/2-wavelength setting. Large olivine crystals are seen as colorful structures in a complex mineral matrix (Image credit: Anna Morris, Astronomy & Astrophysics Research Lab, NCMNS).

The Tissint meteorite is classified as a shergottite, one of the four main subdivisions of meteorites from Mars, and representing nearly 3/4 of all Mars meteorites. Shergottites are igneous, meaning they formed from the cooling and solidification of lava during a time of active volcanism on Mars.  The shergottite group is named after the first of these meteorite types, the Shergotty meteorite, which fell in Sherghati India in 1865. Tissint is an igneous basalt that is rich in the mineral olivine, large inclusions of which are readily evident in thin sections.

Unlike other types of meteorites that are very primitive solar system material, shergottites are most likely younger, with most age estimates ranging from less than one million to several million years old; however, the large degree of processing from magma and impacts make these samples more difficult to age than primitive, pristine samples.  A 2014 (and controversial) paper in the journal Science  suggested that the Mojave crater on Mars could be the source of the shergottite meteorites, and that the samples represent very ancient material — exceeding 4 billion years — that was ejected from the less-than 5 million year-old crater. The precise age of the shergottites remains comsochemistry’s key unanswered questions.

Terrain model of Mojave Crater on Mars, generated from a stereo pair of images provides this synthesized, oblique view of a portion of the wall terraces of Mojave Crater in the Xanthe Terra region of Mars. The model yielding this view combines data from a pair of images taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter (Image credit: NASA/JPL-Caltech/University of Arizona).

Terrain model of Mojave Crater on Mars, generated from a stereo pair of images provides this synthesized, oblique view of a portion of the wall terraces of Mojave Crater in the Xanthe Terra region of Mars. The model yielding this view combines data from a pair of images taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter (Image credit: NASA/JPL-Caltech/University of Arizona).

A fairly substantial body is thought to have been necessary to hit Mars hard enough to eject material from the surface in order to  escape its gravity, which is about 38% that of Earth’s gravity. The large olivine crystals in Tissint show cracks that are the likely signatures from this impact event. Long black veins are also thought to be the result of shocking the rock, and the matrix (the material surrounding the olivine crystals) contains a glassy material called maskelynite plagioclase that formed during impact.

The images below show close-ups of two different olivine crystals in our sample, and their surrounding matrix. The left, middle, and right columns are 1/4, 1/2 and one-wavelength, which describes the different polarizer settings, each of which reveals various features including black veins of shocked glass in the matrix, and deep cracks in the olivine crystals.

Close-up polarized light image of an olivine crystal in our Tissint thin section. Deep cracks can be seen running through the crystal. Left to right: 1/4, 1/2 and 1-wavelength of light. Top to bottom: 5x, 10x, 20x, 50x zoom (Image credit: Anna Morris, Astronomy & Astrophysics Research Lab, NCMNS).

Close-up polarized light image of an olivine crystal in our Tissint thin section. Deep cracks can be seen running through the crystal. Left to right: 1/4, 1/2 and 1-wavelength of light. Top to bottom: 5x, 10x, 20x, 50x zoom (Image credit: Anna Morris, Astronomy & Astrophysics Research Lab, NCMNS).

Close-up polarized light image of an olivine crystal in our Tissint thin section. Deep cracks can be seen running through the crystal. Left to right: 1/4, 1/2 and 1-wavelength of light. Top to bottom: 5x, 10x, 20x, 50x zoom (Image credit: Anna Morris, Astronomy & Astrophysics Research Lab, NCMNS).

Close-up polarized light image of an olivine crystal in our Tissint thin section. Deep cracks can be seen running through the crystal. Left to right: 1/4, 1/2 and 1-wavelength of light. Top to bottom: 5x, 10x, 20x, 50x zoom (Image credit: Anna Morris, Astronomy & Astrophysics Research Lab, NCMNS).

Tissint was discovered by nomads in the small town of Tissint east of Tata, Morocco, on July 18, 2011. It is the fifth Martian meteorite seen to fall to Earth (as opposed to “finds”, or meteorites that are found some time after falling), and is scientifically more valuable than the former given that samples are less weathered, and the trajectory of the meteor can be studied as well. The sky reportedly shown bright yellow during the fall, and two sonic booms were heard.

Anna Morris, Astronomy & Astrophysics Research Lab volunteer, working at our Nikon Polarizing light microscope. Anna's main project in the Lab is to image our meteorite thin sections at a wide range of magnifications and various polarization settings. The images can then be used for identification and further analysis of the minerals.

Anna Morris, Astronomy & Astrophysics Research Lab volunteer, working at our Nikon Polarizing light microscope. Anna’s main project in the Lab is to image our meteorite thin sections at a wide range of magnifications and various polarization settings. The images can then be used for identification and further analysis of the minerals.

We are grateful to Donald Cline, Director and CEO of the Pisgah Astronomical Research Institute, for providing the thin sections to the Museum for our work.

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I am an observational astronomer studying solar system origins from a different vantage point: outside of our solar system. I use the largest ground-based optical/infrared telescopes to study the chemistry of forming planetary systems in our Galaxy, and compare these data to the oldest material from our solar system, including meteorites and the Sun. My astronomical data directly connect to understanding unusual chemistry in the most primitive meteorites, which helps in understanding the earliest processes that influenced how planets formed here, and beyond the solar system. I am interested in expanding our meteorite studies in the Lab. You can visit some key meteorite specimens on display in the meteorite exhibit, adjacent to the Astronomy & Astrophysics Research Lab. Also, visit my Museum webpage and other research blogs if you would like to learn more about my research.

Happy Birthday, Carl Sagan!

November 9, 2014

One of the great astrophysical minds and proponents for reaching beyond our limits as a species, was Dr. Carl Sagan, born today, November 9, 1934. Dr. Sagan died from an illness in 1996, but his voice and contributions to exploring the cosmos live on.

Carl Sagan was a big supporter of SETI — the Search for Extraterrestrial Intelligence — and he convinced NASA to put the Golden Records on the Voyager Probes, now just beyond the solar system, in the slim, slim chance an intelligent alien civilization might eventually find them. He believed in reaching past our limitations as a species, while protecting our small planet and its inhabitants. Dr. Sagan’s original 1980 television series, Cosmos: A Personal Voyage, put astrophysics and exploration of the Universe on the map of public interest — an achievement that survives today. He hoped to one day see a human colony on Mars, and perhaps, if still alive, he might have helped push our space program to achieve that goal.

Perhaps one of Dr. Sagan’s most profound speeches, The Pale Blue Dot, centered on the image of Earth taken, on his suggestion to NASA, with one of the Voyager probes at a distance near the outer planets. This image showed Earth, for the first time, as a tiny dot in a vast sea of space, and generated a more humble perspective of our place in the cosmos. His voice, along with the Voyager images he inspired, can still be enjoyed, below:

You can read more about the Voyager mission and its journey out to interstellar space here.

Revolutionary Image of Planet Formation Around a Young Sun-like Star

November 8, 2014

A few days ago, astronomers using the Atacama Large Millimeter Array telescope (or, ALMA) released this astonishing image:

Protoplanetary disk surrounding the young star HL Tau (Credit: ALMA (NRAO/ESO/NAOJ); C. Brogan, B. Saxton (NRAO/AUI/NSF).

Protoplanetary disk surrounding the young star HL Tau (Credit: ALMA (NRAO/ESO/NAOJ); C. Brogan, B. Saxton (NRAO/AUI/NSF).

This is an image of a protoplanetary disk — the ring of gas and dust that astronomers think surrounds most forming stars (or, protostars). The image amazes for a few reasons. It is the first image to show the detailed concentric rings indicative of planet formation in a protoplanetary disk. This visualization of real-time planet formation looks startlingly like artistic renderings of protoplanetary disks often used in interpreting fuzzy astronomical images.

Artistic rendering of a protoplanetary disk around a young star, much like HL Tau. Planets are shown forming in the gaps in the disk (Credit: National Science Foundation, A. Khan).

Artistic rendering of a protoplanetary disk around a young star, much like HL Tau. Planets are shown forming in the gaps in the disk (Credit: National Science Foundation, A. Khan).

Even more interesting, perhaps, is that the protostar, HL Taurus (often referred to as HL Tau), is less than one million years old, too young, scientists thought, to have a forming system of planets. The now certain fact that there are orbiting bodies well on their way to planet hood implies that planets can form far earlier than originally thought. An earlier history for planet formation means that initial thinking on the chemistry and physics that drive planet formation will need to be reconsidered.

HL Tau is a Sun-like protostar that resides about 450 light-years from Earth in the constellation Taurus (the Bull), but being in the pre-star phase of its evolution and surrounded by a large disk of gas and dust renders it only visible at infrared wavelengths. Being similar in mass and type to our Sun, it is one of the best analogues for the early Solar System, and astronomers study the chemistry of the gas and dust surrounding this and other protostars like it to better understand how our own planetary system evolved.

This image is particularly fascinating for me, since my colleagues and I recently submitted for publication to The Astrophysical Journal (Smith et al., now in revision) one of the most detailed chemical analyses of HL Tau taken with the powerful Very Large Telescope (VLT) in Chile. Our analyses of our very high-resolution observations of carbon monoxide absorption lines in the gas surrounding this object revealed patterns in the oxygen isotopes that are consistent with the as-yet-unexplained patterns seen in the most primitive meteorites, hinting at early solar system processes that could have contributed to this unusual chemistry.

Spectrum of carbon monoxide gas in the protoplanetary disk surrounding the young protostar HL Tau, taken with the Very Large Telescope (Credit: R. Smith, Smith et al., The Astrophysical Journal, paper in revision).

Spectrum of carbon monoxide gas in the protoplanetary disk surrounding the young protostar HL Tau, taken with the Very Large Telescope (Credit: R. Smith, Smith et al., The Astrophysical Journal, paper in revision).

Now it seems that what we once considered primitive, pre-planetary processes could in fact be affecting planets directly as they form. These new revelations will likely change how we interpret our astronomical observations, and how we understand the early chemistry affecting planet formation, organic compounds, and, eventually, life.

You can watch a brief webcast from the National Radio Astronomical Observatory discussing this new image of the HL Tau exoplanetary system below:

 

Click the highlighted links to learn more about my research on solar system origins, and the Astronomy & Astrophysics Research Lab at the Museum!

Making History: Rosetta Catches its Comet on November 12!

November 8, 2014

It’s an exciting time for solar system scientists, as on Wednesday, November 12, 2014, the European Space Agency‘s Rosetta mission will become the first spacecraft in human history to land on a comet — one of the primitive, icy bodies that are left overs from our solar system’s formation about 4.6 billion years ago.

Rosetta is scheduled to touchdown on comet 67P/Churyumov-Gerasimenko (“67P/C-G” for short) at 10:35 AM Eastern Time, with a signal confirming the landing reaching Earth at 11:03 AM. A live-stream of the landing will be available as a webcast, and a special free public program will be held in our Daily Planet Theater, including the live stream and presentation by Dr. Rachel Smith, Director of the Astronomy & Astrophysics Research Lab at the Museum.

Artistic rendering of Rosetta's robotic lander, Philae, touching down on Comet 67P's surface (Credit: NASA).

Artistic rendering of Rosetta’s robotic lander, Philae, touching down on Comet 67P’s surface (Credit: NASA).

Rosetta first made history on August 4, 2014, when it awoke from its ten-year hibernation while en route to comet 67P/C-G to became the first spacecraft to lock in synchronous orbit with a comet. When its robot lander, called Philae, will deploy next week, Rosetta will begin unprecedented detailed studies of the comet’s nucleus — the big chunk of ice and rock that comprises much of the mass, and coma — the material that spews off the surface when it begins to sublime during its approach toward a few hundred million miles of the Sun. This spewed material creates the images that we are perhaps most familiar with when we think of comets coming close to Earth.

Partos

Anatomy of a comet, showing the nucleus, coma, and tail (Credit: NASA).

Comets are thought to be one of the most primitive groups of solar system bodies, vestiges of our early formation that hold clues to our chemical origins. Like the asteroids we see more frequently (and pieces of which we find on Earth as meteorites), comets impacted Earth and other planets and moons in the past. One of the most burning questions that Rosetta will help answer is how Earth obtained its oceans; many scientists think that comets could have seeded our planet’s oceans through impacts during our early history several billion years ago. In 2011, spectroscopic measurements from the Herschel Space Observatory showed that water from comet Hartley 2 was chemically very similar to Earth’s water; Rosetta will analyze the chemistry of water in Comet 67P/C-G in even greater detail to thoroughly investigate the comet origin theory.

Could comets have seeded our oceans billions of years ago? New analyses and missions to comets are helping scientists investigate this question (Credit: NASA/JPL).

Could comets have seeded our oceans billions of years ago? New analyses and missions to comets are helping scientists investigate this question (Credit: NASA/JPL).

Further, in 2006, the mission Stardust passed through the tail of comet Wild 2, collecting tiny particles that were found to be rich in organic matter. These particles support the theory that, like our oceans, organic molecules, including the building blocks of living organisms, could have been seeded by cometary impacts. One of  Rosetta’s key scientific missions will be to study a detailed inventory of Comet 67P/C-G’s chemical, mineralogical, and isotopic composition in order to advance our understanding of organics on comets and how they may relate to the origin of life on Earth.

Comet 67P/C-G is about 3 AU from the Sun, or 450 million km, about 3 times the distance from the Earth to the Sun. After landing its robot onto the surface, Rosetta will travel with 67P/C-G as it travels to the inner solar system and is heated by the Sun, enabling first-ever studies of detailed changes to a comet occurring during its approach to perihelion (a body’s closest distance to the Sun).

Earlier this year, Rosetta’s cameras sent images of the 67P/C-G’s surface, showing its dual-lobed surface in startling, first-ever detail. A few of these spectacular images are shown below; you can find a wider selection of images from Rosetta on the JPL website.

Comet 67P/Churyumov-Gerasimenko's dimensions, as measured from images taken by Rosetta's OSIRIS imaging system. The images shown in the graphic were taken by Rosetta's navigation camera on August 19, 2014. The larger lobe of the comet measures 4.1 x 3.2 x 1.3 km, while the smaller lobe is 2.5 x 2.5 x 2.0 km (Credit: ESA/Rosetta/NAVCAM; Dimensions: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA).

Comet 67P/Churyumov-Gerasimenko’s dimensions, as measured from images taken by Rosetta’s OSIRIS imaging system. The images shown in the graphic were taken by Rosetta’s navigation camera on August 19, 2014. The larger lobe of the comet measures 4.1 x 3.2 x 1.3 km, while the smaller lobe is 2.5 x 2.5 x 2.0 km (Credit: ESA/Rosetta/NAVCAM; Dimensions: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA).

Comet 67P on November 4, 2014. This mosaic comprises four individual  images taken with Rosetta's "NAVCAM" camera from 31.8 km from the center of the comet. The original 1024 x 1024 pixel frame measured 2.8 km across. The mosaic has been slightly rotated and cropped, and measures roughly 4.6 x 3.8 km (Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0).

Comet 67P on November 4, 2014. This mosaic comprises four individual images taken with Rosetta’s navigation camera (NAVCAM) from 31.8 km from the center of the comet. The original 1024 x 1024 pixel frame measured 2.8 km across. The mosaic has been slightly rotated and cropped, and measures roughly 4.6 x 3.8 km (Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0).

Four-image montage comprising images taken by Rosetta's navigation camera (NAVCAM) from a distance of 9.7 km from the center of comet 67P, about 7.7 km from the surface. The corresponding image scale is about 65 cm/pixel, so each 1024 x 1024 pixel frame is about 665 meters across. (Credit: ESA/Rosetta/NAVCAM)

Four-image montage comprising images taken by Rosetta’s navigation camera (NAVCAM) from a distance of 9.7 km from the center of comet 67P, about 7.7 km from the surface. The corresponding image scale is about 65 cm/pixel, so each 1024 x 1024 pixel frame is about 665 meters across. (Credit: ESA/Rosetta/NAVCAM)

Next week’s soft landing will be scientifically groundbreaking, and one of the most exciting times for planetary science! Join us on Wednesday in the Daily Planet theater to witness this live landing, and hear more about Rosetta’s science and technological breakthroughs.

Solar system research at the Museum: I am an observational astronomer studying solar system origins from a different vantage point: outside of our solar system. I use the largest ground-based optical/infrared telescopes to study the chemistry of forming planetary systems in our Galaxy, and compare these data to the oldest material from our solar system, including meteorites, the Sun, and hopefully soon, Comet 67P/C-G. Visit my Museum webpage and other research blogs as well as the astrophysics displays in the Astronomy & Astrophysics Research Lab and the Museum’s meteorite collection to learn more!

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