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Analysing large carbonaceous molecules in cosmic environments – Innovation News Network

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Dr Christine Joblin of the CNRS and her colleague Dr Hassan Sabbah of the University of Toulouse III – Paul Sabatier highlight the ability of the AROMA molecular analyser to understand the origin of large carbonaceous molecules in cosmic environments.

The James Webb Space Telescope (JWST, NASA/ESA/CSA) has just revealed its amazing capabilities to study the Universe at infrared wavelengths. Among the data, we expect unprecedented information about large carbonaceous molecules that are key species in star- and planet-forming regions.2 These molecules are dominated by the family of polycyclic aromatic hydrocarbons (PAHs) – well-known terrestrial pollutants that are major by-products of combustion processes. It remains to be understood why these PAHs are so abundant in astrophysical environments (they typically contain 10% of the carbon).

What are the mechanisms that recycle carbon in space and (preferentially) form these molecules? So far, the research has been mainly guided by our knowledge of flame chemistry and the proposal that astro-PAHs are produced at the end of the life of carbon-rich stars, in hot and dense envelopes in which the formation of dust and molecular species, such as PAHs, is favoured. Still, as of today, we have no clear observational diagnosis to demonstrate this scenario. In addition, the individual PAHs that have been identified so far (indene C9H8 and cyano-naphthalene C10H7CN)4,5 are present in the TMC-1 dark molecular cloud and are most likely products of very low temperature gas-phase chemistry.

The PAH model

Over the past decade, the unambiguous detection of C60 buckminsterfullerene and its C60+ cation in a variety of astrophysical environments has been a major achievement. It has allowed support for the PAH model. This model, proposed in the 1980s, explains that all the strong aromatic infrared bands observed in emission come from radiative cooling of PAHs heated by ultraviolet photon absorption. We now know that other carriers, such as fullerenes, must be included. Compared to PAHs, the formation of fullerenes requires more extreme conditions – in particular, higher temperatures. This issue motivates studies to propose formation scenarios for C60 in astrophysical environments. These include processing of grains by heat, shocks or high-energy ions and UV photo-processing of large PAHs.6,7

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In this paper, we present our approach to address the question of the formation of astro-PAHs and fullerenes from an experimental point of view. This approach is based on two pillars. The first pillar is to use a variety of reactors to produce samples that can be considered as laboratory analogues of stardust. Although it is impossible to mimic the physical and chemical conditions of dying stars, a new machine, Stardust,8 has been built in Madrid (ICMM/CSIC) to advance in this field by offering features not available in other experimental setups, such as the controlled production of (e.g, carbon, silicon) atoms to drive the chemistry.

Cold plasmas are also used as an alternative method to study the impact of complexity on chemistry. In particular, we study the role of metal (e.g., iron) atoms in the formation of dust and large carbonaceous molecules with our colleagues from LAPLACE (CNRS/ Université Toulouse III-Paul Sabatier).9 The second pillar consists of studying samples of extra-terrestrial matter (meteorites) that are rich in carbon. This is the case of carbonaceous chondrites like Murchison and Allende but also of the polymict ureilite meteorite Almahata Sitta (AhS). These two pillars share the common interest of probing the carbonaceous molecular content of samples that may be in the form of dusty deposits or bulk materials, as illustrated in Fig. 1. This topic motivated the development of the Astrochemistry Research of Organics with Molecular Analyzer (AROMA) setup.

Fig. 1: Different types of samples analysed with the AROMA setup. On the left, atomic force microscopic image of Stardust analogues showing the presence of carbon nanoparticles8 and a scanning electron microscope image of dusty plasma analogues showing organosilicon dust decorated with silver nanoparticles.9 In the middle, small fragments of the AhS meteorite observed with a digital microscope12 and image of one of the Hayabusa2 sample container (Yada et al., DOI: 10.1038/s41550-021-01550-6). On the right, picture of the emission of soot particles (Source: COLOA Studio/Shutterstock) and asphaltenes from oil pipelines (Credit: Schlumberger). The structures of the PAH prototype, C16H10 pyrene and C60 fullerene are shown at the bottom

AROMA: the molecular analyzer

The AROMA setup10 has been developed in the framework of the Nanocosmos ERC Synergy project.1 The construction was done by Fasmatech, a young Greek company, following the requirements of our scientific and engineering team. The main objective is to trace the molecular content of various solid samples, especially in large molecules such as polycyclic aromatic hydrocarbons, carbon clusters and fullerenes.

AROMA, as shown in Fig. 2a, consists of three main components: the ion source, the ion trap, and the mass analyzer.

In the ion source, millimetre-sized samples are positioned on an XY manipulator and subjected to laser desorption/ionisation (LDI) techniques. LDI techniques, using a single laser step, are powerful tools for directly probing non-volatile organic species in native or artificial matrices without the need for tedious extraction procedures. In the case of high molecular weight compounds, such as biomolecules, a matrix-assisted LDI (MALDI) technique is typically used. The specificity of AROMA is the use of the L2MS technique, in which the desorption and ionisation processes are separated in time and space and performed with two different lasers. A pulsed infrared laser is used to desorb neutral molecules, followed after a few microseconds by a pulsed ultraviolet laser to selectively ionise the molecules of interest.13 L2MS offers a much higher sensitivity than one-step LDI to the targeted molecules (e.g., in our case, PAHs and fullerenes). In addition, AROMA offers the possibility to isolate and trap ions of a specific mass and to study their fragmentation by collisions with a gas or by absorption of photons from a tuneable laser. Both techniques help us to elucidate the molecular structures of the dominant species. Finally, the ions are mass separated using a high-resolution time-of-flight mass spectrometer (104 resolving power).

large carbonaceous molecules
Fig. 2: (a) Mass spectrum recorded from a bulk sample of the Murchison meteorite. Some of the identified peaks are shown with their mass-to-charge ratio (m/z), associated chemical formula and possible molecular structure. (b) Schematic representation of the AROMA setup highlighting all its components

Fig. 2 shows an example of a mass spectrum recorded for a few mg of crushed powder from the Murchison meteorite. It plots the intensity of the ion signal as a function of the mass-to-charge ratio. This allows us to unequivocally assign a chemical formula to each detected peak and associate it with a pure carbon (Cx) or hydrocarbon (CxHY) species. Other elements, especially in atomic form, may also be present (for example, Na, Al, K, Fe, etc.). Our assignment accuracy approaches 0.01 at a mass/charge ratio m/z ~300. This is our limitation to assign with high confidence organic compounds with N, O and S atoms in their chemical formula. Eventually, hundreds of peaks are identified in the mass spectra with notable discrepancies between different samples. The latter can be used to trace the chemical history of each sample and are not a bias of our analysis.

For example, in the analysis of terrestrial soot samples,11 we were able to track the evolution of carbonaceous molecular families, as a function of height above the burner (Z) and demonstrate efficient thermal processing of the large PAH population to produce hydrogenated carbon clusters (HC clusters) and then fullerenes (see Fig. 3a). To recover this chemical information, large mass spectrometry datasets must be reduced to relevant parameters such as molecular families. For this, our methodology consists in calculating double bond-equivalent (DBE) values, which are representative of the unsaturation level of the molecules. The different ranges of DBE values allow us to disentangle the molecular families: PAHs, HC clusters, aliphatic species (very rare in our samples because the ultraviolet laser is not adapted to their ionisation), carbon clusters and fullerenes.

large carbonaceous molecules
Fig. 3: Compositional diversity in the four molecular families (PAHs, HC clusters, C clusters, and fullerenes) obtained after DBE analysis. (a) Soot samples collected at different heights above the burner11 and analogues produced with the Stardust machine using atomic carbon and different gases (H2 from8 and C2H2 from Santoro et al, DOI: 10. 3847/1538-4357/ab9086 ). (b) Murchison, Allende and two AhS meteorite fragments10,12

Fig. 3 illustrates the method and shows the results of molecular family analysis for several samples, including terrestrial soot, stardust analogues (Fig. 3a), and several meteorites (Fig. 3b). PAHs dominate the molecular composition of carbonaceous chondrites (Murchison and Allende). In contrast, the two AhS fragments, AhS#04 and AhS#48, show a greater diversity of molecular families, which have been shown to originate from different cosmic reservoirs.

All mass spectra associated with published work are publicly available in the AROMA database. The database provides the ability to calculate and plot DBE values, and to perform molecular family analyses. We are also developing a method to assess the similarity between recorded mass spectra and how it can be used to provide faster investigation and additional information about the chemical history of a sample.

Amazing results and perspectives

Initially seen as an analytical tool to support the Stardust machine, AROMA has now become a key facility to contribute to our understanding of the origin of large carbonaceous molecules in cosmic environments. In the term cosmic, we include astrophysical environments (e.g., evolved stars as stardust factories) but also our Solar System, via extra-terrestrial samples that we can access in the laboratory.

In connection with the Stardust machine, the most important result we have obtained so far is the near absence of aromatics formed in the chemistry of atomic carbon with molecular hydrogen. This casts doubt on the possibility of forming abundant PAHs by gas-phase chemistry in the envelopes of evolved stars.

But the result that opens up the greatest prospects is certainly the unexpected but firm detection of fullerenes, from C30 to at least C100, in the Almahata Sitta (AhS) polymict ureilite meteorite. We are now in a rather unique position to search for fullerenes in a variety of extra-terrestrial samples. In particular, we were recently fortunate to receive two grains from the asteroid Ryugu that were carried by JAXA’s Hayabusa2 sample return mission. Ryugu is a C-type asteroid that is considered one of the most pristine objects in the Solar System. The analysis of this type of object will allow us to circumvent the problem of meteorite alteration linked to the shocks during their ejection and to the heating during their entry into the Earth’s atmosphere, as well as to a possible terrestrial contamination. We believe that this work can give us new insight into the origin of fullerenes in astrophysical environments.

We also expect a big step forward with the next JWST results, including the identification of individual species among the molecular families studied by AROMA: fullerenes, PAHs, C clusters, as well as new information on the chemical relationship between these families and with the dust particles.

The prospect of changing our view of the cosmic carbon cycle has never been closer and it is quite exciting. In addition to the fantastic challenges that JWST and Hayabusa2 have met, innovation will also be required on the laboratory side. A major advance that we hope to address in our research activity is the possibility to couple the L2MS technique to an OrbitrapTM mass analyser that offers very high mass resolution and thus opens new perspectives to trace the origin of organic matter in samples of cosmic interest.

Acknowledgements

This research was supported over the period 2014-2021 by the ERC under the European Union’s Seventh Framework Programme ERC-2013-SyG, Grant Agreement no. 610256, Nanocosmos.

References (with open access)

1: Nanocosmos ERC Synergy project: J Cernicharo, C. Joblin, J.-A. Martín Gago, https://nanocosmos.iff.csic.es/

2: Early Release Science of JWST: “Radiative feedback from massive stars”: Berné, O, Habart, E, Peeters, E, et al., Publ. Astron. Soc. Pac. 134 (1035) (2022), id.054301; https://arxiv.org/abs/2201.05112

3: “Astro-PAHs from space missions to laboratory astrophysics”; Joblin, C, The Innovation Platform issue 8 (2021), p.228-231; https://www.innovationnewsnetwork.com/astro-pahs-space-missions-to-laboratory-astrophysics/15527/

4: Observation of indene in the dark molecular cloud TMC-1: Cernicharo, J, et al., Astron. & Astrophys. 649 (2021), id.L15, 12 pp.; https://doi.org/10.1051/0004-6361/202141156

5: Observation of cyanonaphthalene in the dark molecular cloud TMC-1: McGuire, B. A., et al., Science 371 (2021), 1265–1269; https://arxiv.org/pdf/2103.09984.pdf

6: Discussion about formation scenarios of C60 in planetary nebulae: Cami, J., et al., Galaxies 6 (4) (2018), p. 101; https://www.mdpi.com/2075-4434/6/4/101

7: Scenario to form C60 from large PAHs: Berné, O, Tielens, A G G M, Proc. Natl. Acad. Sci. U.S.A. 109 (2012), 401-406; https://doi.org/10.1073/pnas.111420710

8: Stardust machine and the (non)formation of aromatics in evolved stars: Martínez, L, Santoro, G, Merino, P, et al., Nature Astron. 4 (2020), 97-105; https://hal.archives-ouvertes.fr/hal-03085475

9: Role of metals in (star)dust chemistry investigated in cold plasmas: Bérard, R, et al., Front. astron. space sci. 8 (2021), 654879; https://hal.archives-ouvertes.fr/hal-03227179

10: AROMA setup: Sabbah, H, et al., Astrophys. J. 843 (2017), id. 34, 8 pp.; https://arxiv.org/ftp/arxiv/papers/1705/1705.09974.pdf

11: Analysis of soot samples with AROMA: Sabbah, H, et al., Proc Combust Inst 38 (2021), 1241–1248; https://doi.org/10.1016/j.proci.2020.09.022

12: Detection of fullerenes in the Almahata Sitta meteorite: Sabbah, H, et al., Astrophys. J. 931 (2022), id.91; https://iopscience.iop.org/article/10.3847/1538-4357/ac69dd

13: First presentation of the L2MS technique and its application to extra-terrestrial samples: Spencer, M K, Hammond, M R, and Zare, R N, Publ. Astron. Soc. Pac. 105 (2008), 18096-18101; https://doi.org/10.1073/pnas.0801860105

Please note, this article will also appear in the eleventh edition of our quarterly publication.

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NASA to launch sounding rockets into moon's shadow during solar eclipse – Phys.org

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This photo shows the three APEP sounding rockets and the support team after successful assembly. The team lead, Aroh Barjatya, is at the top center, standing next to the guardrails on the second floor. Credit: NASA/Berit Bland

NASA will launch three sounding rockets during the total solar eclipse on April 8, 2024, to study how Earth’s upper atmosphere is affected when sunlight momentarily dims over a portion of the planet.

The Atmospheric Perturbations around Eclipse Path (APEP) sounding rockets will launch from NASA’s Wallops Flight Facility in Virginia to study the disturbances in the created when the moon eclipses the sun. The sounding rockets had been previously launched and successfully recovered from White Sands Test Facility in New Mexico, during the October 2023 .

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They have been refurbished with new instrumentation and will be relaunched in April 2024. The mission is led by Aroh Barjatya, a professor of engineering physics at Embry-Riddle Aeronautical University in Florida, where he directs the Space and Atmospheric Instrumentation Lab.

The sounding rockets will launch at three different times: 45 minutes before, during, and 45 minutes after the peak local eclipse. These intervals are important to collect data on how the sun’s sudden disappearance affects the ionosphere, creating disturbances that have the potential to interfere with our communications.

The ionosphere is a region of Earth’s atmosphere that is between 55 to 310 miles (90 to 500 kilometers) above the ground. “It’s an electrified region that reflects and refracts and also impacts as the signals pass through,” said Barjatya. “Understanding the ionosphere and developing models to help us predict disturbances is crucial to making sure our increasingly communication-dependent world operates smoothly.”

A sounding rocket is able to carry science instruments between 30 and 300 miles above Earth’s surface. These altitudes are typically too high for science balloons and too low for satellites to access safely, making sounding rockets the only platforms that can carry out direct measurements in these regions. Credit: NASA’s Goddard Space Flight Center

The ionosphere forms the boundary between Earth’s lower atmosphere—where we live and breathe—and the vacuum of space. It is made up of a sea of particles that become ionized, or electrically charged, from the sun’s energy or .

When night falls, the ionosphere thins out as previously ionized particles relax and recombine back into neutral particles. However, Earth’s terrestrial weather and space weather can impact these particles, making it a dynamic region and difficult to know what the ionosphere will be like at a given time.

It’s often difficult to study short-term changes in the ionosphere during an eclipse with satellites because they may not be at the right place or time to cross the eclipse path. Since the exact date and times of the are known, NASA can launch targeted sounding rockets to study the effects of the eclipse at the right time and at all altitudes of the ionosphere.

As the eclipse shadow races through the atmosphere, it creates a rapid, localized sunset that triggers large-scale atmospheric waves and small-scale disturbances or perturbations. These perturbations affect different radio communication frequencies. Gathering the data on these perturbations will help scientists validate and improve current models that help predict potential disturbances to our communications, especially high-frequency communication.

This conceptual animation is an example of what observers might expect to see during a total solar eclipse, like the one happening over the United States on April 8, 2024. Credit: NASA’s Scientific Visualization Studio

The APEP rockets are expected to reach a maximum altitude of 260 miles (420 kilometers). Each rocket will measure charged and neutral particle density and surrounding electric and magnetic fields. “Each rocket will eject four secondary instruments the size of a two-liter soda bottle that also measure the same data points, so it’s similar to results from fifteen rockets while only launching three,” explained Barjatya. Embry-Riddle built three secondary instruments on each rocket, and the fourth one was built at Dartmouth College in New Hampshire.

In addition to the rockets, several teams across the U.S. will also be taking measurements of the ionosphere by various means. A team of students from Embry-Riddle will deploy a series of high-altitude balloons. Co-investigators from the Massachusetts Institute of Technology’s Haystack Observatory in Massachusetts and the Air Force Research Laboratory in New Mexico will operate a variety of ground-based radars taking measurements.

Using this data, a team of scientists from Embry-Riddle and Johns Hopkins University Applied Physics Laboratory are refining existing models. Together, these various investigations will help provide the puzzle pieces needed to see the bigger picture of ionospheric dynamics.

The animation depicts the waves created by ionized particles during the 2017 total solar eclipse. Credit: MIT Haystack Observatory/Shun-rong Zhang. Zhang, S.-R., Erickson, P. J., Goncharenko, L. P., Coster, A. J., Rideout, W. & Vierinen, J. (2017). Ionospheric Bow Waves and Perturbations Induced by the 21 August 2017 Solar Eclipse. Geophysical Research Letters, 44(24), 12,067-12,073. https://doi.org/10.1002/2017GL076054

When the APEP- launched during the 2023 annular solar eclipse, scientists saw a sharp reduction in the density of charged particles as the annular eclipse shadow passed over the atmosphere.

“We saw the perturbations capable of affecting radio communications in the second and third rockets, but not during the first rocket that was before peak local eclipse,” said Barjatya. “We are super excited to relaunch them during the total eclipse to see if the perturbations start at the same altitude and if their magnitude and scale remain the same.”

The next total solar eclipse over the contiguous U.S. is not until 2044, so these experiments are a rare opportunity for scientists to collect crucial data.

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Royal Sask. Museum research finds insect changes may have set stage for dinosaurs' extinction – CTV News Regina

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Research by the Royal Saskatchewan Museum (RSM) shows that ecological changes were occurring in insects at least a million years before dinosaur extinction.

Papers published in the scientific journal, Current Biology, describe the first insect fossils found in amber from Saskatchewan and the unearthing of three new ant species from an amber deposit in North Carolina, according to a release from the province.

The amber deposit from in the Big Muddy Badlands of Saskatchewan, which was formed about 67 million years ago, preserved insects that lived in a swampy redwood forest about one million years before the extinction of dinosaurs.

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“Fossils in the amber deposit seem to show that common Cretaceous insects may have been replaced on the landscape by their more modern relatives, particularly in groups such as ants, before the extinction event,” Elyssa Loewen, curatorial assistant, said.

The research team was led by Loewen and Dr. Ryan McKellar, the RSM’s curator of paleontology.

“These new fossil records are closer than anyone has gotten to sampling a diverse set of insects near the extinction event, and they help researchers fill in a 17-million-year gap in the fossil record of insects around that time,” Dr. McKellar said.

The three ant species discovered in North Carolina also belonged to extinct groups that didn’t survive past the Cretaceous period.

“When combined with the work in Saskatchewan, the two recent papers show that there was a dramatic change in ant diversity sometime between 77 and 67 million years ago,” Dr. McKellar said in the release.

“Our analyses of body shapes in the fossils suggests that the turnover was not related to major differences in ecology, but it may have been related to something like the size and complexity of ant colonies. More work is needed to confirm this.”

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Meteors, UFOs or something else? Dawson City, Yukon, residents puzzled by recent sightings in night sky – CBC.ca

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Some residents in Dawson City, Yukon, say they’ve been seeing unusual things in the night sky lately — and it’s not the Northern Lights. 

But some might say it’s equally as fascinating.

Over the past few weeks, some residents have taken to social media to report seeing what they described as a fireball or meteor overhead. And last week, two residents said they both saw something similar.

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Naomi Gladish lives in Henderson Corner, a subdivision approximately 20 kilometres from downtown Dawson City. She told CBC News she saw something while walking her dog Friday morning.

“I looked up and saw a bright star,” Gladish said. “Or what I thought was a star.” 

“Within a fraction of a second, I realized it was actually moving quickly. And then as I watched it, a second later it grew a long tail.”

Dawson City resident Naomi Gladish said she saw something similar to the fireball shown in this image from the American Meteor Society. (American Meteor Society)

Gladish said the unknown object started to change into a pale blue colour, like a gas flame. Then, a few seconds later, it appeared to burn out.

“I could see fire, or coal,” Gladish said. “Like red glowing bits, breaking off of it. And then that was it. I tried watching to see if I could see any dark chunks falling from that spot, or carrying on from that spot, but the sky was dark.”

A minute or two after Gladish saw what she thought was a meteor, she heard a boom in the distance.

“My dog and I both turned our head to that exact direction that I had just seen it,” she said.”I figured it was related.”

Two women walking through snowy mountain terrain.
Naomi Gladish hiking with her sister at Tombstone Park. (Submitted by Naomi Gladish)

Dawson resident Jeff Delisle reported seeing something similar at about the same time. He then took to social media to ask if anyone else had seen it. Two people responded saying they had. 

“It flew right above me,” Delisle wrote.

“Pretty cool looking…. What is it?”

Likely not a meteor, says astronomer

Christa Van Laerhoven, president of the Yukon Astronomical Society, came across Delisle’s post and got in touch. She asked about what he’d seen, such as how long it was in the sky and the colour.

Van Laerhoven told CBC News that based on descriptions from both Delisle and Gladish, she doesn’t believe it could have been a meteor.

She says a meteor would have been moving much faster, and the colouring would have appeared differently. 

“Meteors can be any colour but … as a rule, are a consistent colour. What these people were describing had different colours. So the head looked blue and then the tail was more of an orange,” van Laerhoven said.

“That’s just something that doesn’t happen with meteors.”

a meteor
This zoomed-in still from a dashcam video captured in 2020 by Louise Cooke from Mount Lorne, Yukon, shows what one space science expert said appears to be an unusually-bright meteor travelling across the sky. (Submitted by: Louise Cooke)

Van Laehoven believes there may be another explanation for the recent unusual sightings: space junk, falling to earth.

“Space junk, when it comes in … comes through the atmosphere and starts glowing that can be more irregular, because of the variety of materials that go into a spacecraft.”

Van Laerhoven also suggested it could a very fast plane, or someone playing with rockets.

Gladish, however, doesn’t think anyone in Dawson was playing with rockets on Friday morning.

“Unless they’re talking about someone in China, or like a distant land playing with very high, powerful rockets … then sure,” she said.

“This was not something that someone in Dawson was doing … This came from much, much higher and it was much, much different to anything that would be locally caused.”

Van Laerhoven also dismissed another possibility: alien visitors.

“If aliens were coming to Earth, we would know,” she said.

“Simply because it would take them so much effort to get here that it would be very hard to imagine them getting here and not doing something dramatic enough that we would actually know about it.”

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