Where Does High-mass Star Formation (HMSF) Occur? Does The Magnetic Field Play A Key Role In HMSF? (Cosmology)

Patricio Sanhueza and colleagues reported on ALMA high resolution observations of the high-mass star forming region IRAS 18089-1732. They revealed that, the dense molecular envelope surrounding the high-mass star has a complex spiral pattern at the 0.003–0.1 pc scales. Their study recently appeared in Arxiv.

In order to fully understand high-mass star formation, we have to study the magnetic fields. But, it is by far the least explored. Polarization observations can help us to infer the magnetic field in molecular clouds and denser regions associated with star formation. But, at smaller scales i.e. at core-disk interface ~ 1000 au, these observations are far less. Thus, it is difficult to evaluate the importance of the magnetic field in the high mass star formation process.

IRAS 18089−1732, is the high-mass star forming region, located at a parallax distance of 2.34 kpc with a bolometric luminosity of 1.3 × 10⁴ L. It is an ideal laboratory to assess the importance of the magnetic field with respect to turbulence, gravity, and rotation. Earlier studies at arcsec resolution showed that IRAS 18089−1732 has a deeply embedded hot core and a disklike rotating structure roughly perpendicular to a molecular outflow.

Now, Patricio Sanhueza and colleagues reported ALMA 1.2 mm, high-resolution (700 au) dust polarization and molecular line observations of the rotating hot molecular core embedded in the high-mass star-forming region IRAS 18089−1732.

They revealed that the dense molecular envelope surrounding the high-mass star has a complex spiral pattern (much like whirlpool) at the 0.003–0.1 pc scales. This spiral-like morphology is seen in the gas and dust, as well as in the magnetic field.

They have also modeled the magnetic field and found that, the core is weakly magnetized. The estimated magnetic field strength and Alfven speed are 3.5 mG and 1.26 km s¯1, respectively.

In addition, they analyzed the energy balance of the system and showed that, the high-mass star formation can occur in weakly magnetized environments and that gravity is shaping the immediate surrounding (~1000 au scales) around the high-mass star. While, the magnetic field importance is only comparable to turbulence and rotation.

“The overwhelming importance of gravity with respect to the other energies becomes more evident once we included the magnetic field and rotation and calculated the virial parameters.”

Moreover, the spiral magnetic field indicated that, angular momentum is high enough to twist the field lines, as supported by the model and the energy analysis.

“With these observations, we suggest that the importance of the magnetic field in the process of high-mass star formation depends on the size scales traced and the evolutionary stage of the observed region.”

— concluded authors of the study

Featured image: ALMA 1.2 mm dust continuum emission (color scale and contours) toward IRAS 18089-1732 with overlaid magnetic field vectors, which correspond to the dust polarization vectors rotated by 90 deg. Yellow line segments representing the magnetic field orientation are plotted above the 3σ level, with σ = 31.4 µJy beam¯1, and have an arbitrary length. Contours correspond to the dust continuum emission in steps of 4, 6, 10, 18, 34, 66, 130, 258, 514 times the σ (rms) value of 175 µJy beam¯1. Spatial resolution of 700 au (0.3″) is shown on the bottom left. Scale bar is shown on the bottom, right side of the panel. © Patricio Sanhueza et al.


Reference: Patricio Sanhueza, Josep Miquel Girart, Marco Padovani, Daniele Galli, Charles L. H. Hull, Qizhou Zhang, Paulo Cortes, Ian W. Stephens, Manuel Fernandez-Lopez, James M. Jackson, Pau Frau, Patrick M. Kock, Benjamin Wu, Luis A. Zapata, Fernando Olguin, Xing Lu, Andrea Silva, Ya-Wen Tang, Takeshi Sakai, Andres E. Guzman, Ken’ichi Tatematsu, Fumitaka Nakamura, Huei-Ru Vivien Chen, “Gravity Driven Magnetic Field at ~1000 au Scales in High-mass Star Formation”, Arxiv, 2021. https://arxiv.org/abs/2106.03866


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Exoplanets: Liquid Water On Exomoons of Free-floating Planets (Planetary Science)

The moons of planets that have no parent star can possess an atmosphere and retain liquid water. Astrophysicists at LMU have calculated that such systems could harbor sufficient water to make life possible – and sustain it.

Water – in liquid form – is the elixir of life. It made life possible on Earth and is indispensable for the continuing existence of living systems on the planet. This explains why scientists are constantly on the lookout for evidence of water on other solid bodies in the Universe. Up to now, however, the existence of liquid water on planets other than Earth has not been directly proven. However, there are indications that several moons in the outer reaches of our own solar system – more specifically, Saturn’s Enceladus and three of Jupiter’s moons (Ganymede, Callisto and Europa) may possess subterranean oceans. What then are the prospects for the detection of water on the moons of planets beyond our solar system?

In cooperation with colleagues at the University of Concepción in Chile, LMU physicists Prof. Barbara Ercolano and Dr. Tommaso Grassi (both of whom are members of ORIGINS, a Cluster of Excellence) have now used mathematical methods to model the atmosphere and gas-phase chemistry of a moon in orbit around a free-floating planet (FFP). An FFP is a planet that is not associated with a star.

More than 100 billion planetary nomads

FFPs are of interest mainly because the evidence indicates that there are plenty of them out there. Conservative estimates suggest that our own galaxy hosts at least as many Jupiter-sized orphan planets as there are stars – and the Milky Way itself is home to well over 100 billion stars.

Ercolano and Grassi made use of a computer model to simulate the thermal structure of the atmosphere of an exomoon of the same size as the Earth in orbit around a FFP. Their results suggest that the amount of water present on the moon’s surface would be about 10,000 times smaller than the total volume of our planet’s oceans, but 100 times larger than that found in Earth’s atmosphere. This would be enough to enable life to evolve and thrive.

The model from which this estimate was derived consists of an Earth-sized moon and a Jupiter-sized FFP. Such a system, which has no stellar companion nearby, is expected to be dark and cold. Unlike our solar system, there is no central star that can serve as a reliable source of energy to drive chemical reactions.

Rather, in the researchers’ model, cosmic rays provide the chemical drive necessary to convert molecular hydrogen and carbon dioxide into water and other products. To keep the system stirred up, the authors invoke the tidal forces exerted by the planet on its moon as a source of heat – and assuming that carbon dioxide accounts for 90% of the moon’s atmosphere, the resulting greenhouse effect would effectively retain a large part of the heat generated on the moon. Together, these energy sources would suffice to keep water in the liquid state.
International Journal of Astrobiology, 2021

Featured image: Illustration of a planet floating freely through the universe with a moon that can store water. | © Tommaso Grassi / LMU


Reference: Ávila, P., Grassi, T., Bovino, S., Chiavassa, A., Ercolano, B., Danielache, S., & Simoncini, E. (2021). Presence of water on exomoons orbiting free-floating planets: A case study. International Journal of Astrobiology, 1-12. doi:10.1017/S1473550421000173


Provided by LMU Munchen

A New Technique For Correcting Disease-causing Mutations (Medicine)

Novel method, developed by McGovern Institute researchers, may lead to safer, more efficient gene therapies.

Gene editing, or purposefully changing a gene’s DNA sequence, is a powerful tool for studying how mutations cause disease, and for making changes in an individual’s DNA for therapeutic purposes. A novel method of gene editing that can be used for both purposes has now been developed by a team led by Guoping Feng, the James W. (1963) and Patricia T. Poitras Professor in Brain and Cognitive Sciences at MIT.

“This technical advance can accelerate the production of disease models in animals and, critically, opens up a brand-new methodology for correcting disease-causing mutations,” says Feng, who is also a member of the Broad Institute of Harvard and MIT and the associate director of the McGovern Institute for Brain Research at MIT. The new findings were published online May 26 in the journal Cell.

Genetic models of disease

A major goal of the Feng lab is to precisely define what goes wrong in neurodevelopmental and neuropsychiatric disorders by engineering animal models that carry the gene mutations that cause these disorders in humans. New models can be generated by injecting embryos with gene editing tools, along with a piece of DNA carrying the desired mutation.

In one such method, the gene editing tool CRISPR is programmed to cut a targeted gene, thereby activating natural DNA mechanisms that “repair” the broken gene with the injected template DNA. The engineered cells are then used to generate offspring capable of passing the genetic change on to further generations, creating a stable genetic line in which the disease, and therapies, are tested.

Although CRISPR has accelerated the process of generating such disease models, the process can still take months or years. Reasons for the inefficiency are that many treated cells do not undergo the desired DNA sequence change at all, and the change only occurs on one of the two gene copies (for most genes, each cell contains two versions, one from the father and one from the mother).

In an effort to increase the efficiency of the gene editing process, the Feng lab team initially hypothesized that adding a DNA repair protein called RAD51 to a standard mixture of CRISPR gene editing tools would increase the chances that a cell (in this case a fertilized mouse egg, or one-cell embryo) would undergo the desired genetic change.

As a test case, they measured the rate at which they were able to insert (“knock-in”) a mutation in the gene Chd2 that is associated with autism. The overall proportion of embryos that were correctly edited remained unchanged, but to their surprise, a significantly higher percentage carried the desired gene edit on both chromosomes. Tests with a different gene yielded the same unexpected outcome.

“Editing of both chromosomes simultaneously is normally very uncommon,” explains postdoc Jonathan Wilde. “The high rate of editing seen with RAD51 was really striking, and what started as a simple attempt to make mutant Chd2 mice quickly turned into a much bigger project focused on RAD51 and its applications in genome editing,” says Wilde, who co-authored the Cell paper with research scientist Tomomi Aida.

A molecular copy machine

The Feng lab team next set out to understand the mechanism by which RAD51 enhances gene editing. They hypothesized that RAD51 engages a process called interhomolog repair (IHR), whereby a DNA break on one chromosome is repaired using the second copy of the chromosome (from the other parent) as the template.

To test this, they injected mouse embryos with RAD51 and CRISPR but left out the template DNA. They programmed CRISPR to cut only the gene sequence on one of the chromosomes, and then tested whether it was repaired to match the sequence on the uncut chromosome. For this experiment, they had to use mice in which the sequences on the maternal and paternal chromosomes were different.

They found that control embryos injected with CRISPR alone rarely showed IHR repair. However, addition of RAD51 significantly increased the number of embryos in which the CRISPR-targeted gene was edited to match the uncut chromosome.

“Previous studies of IHR found that it is incredibly inefficient in most cells,” says Wilde. “Our finding that it occurs much more readily in embryonic cells and can be enhanced by RAD51 suggest that a deeper understanding of what makes the embryo permissive to this type of DNA repair could help us design safer and more efficient gene therapies.”

A new way to correct disease-causing mutations          

Standard gene therapy strategies that rely on injecting a corrective piece of DNA to serve as a template for repairing the mutation engage a process called homology-directed repair (HDR).

“HDR-based strategies still suffer from low efficiency and carry the risk of unwanted integration of donor DNA throughout the genome,” explains Feng. “IHR has the potential to overcome these problems because it relies upon natural cellular pathways and the patient’s own normal chromosome for correction of the deleterious mutation.”

Feng’s team went on to identify additional DNA repair-associated proteins that can stimulate IHR, including several that not only promote high levels of IHR, but also repress errors in the DNA repair process. Additional experiments that allowed the team to examine the genomic features of IHR events gave deeper insight into the mechanism of IHR and suggested ways that the technique can be used to make gene therapies safer.

“While there is still a great deal to learn about this new application of IHR, our findings are the foundation for a new gene therapy approach that could help solve some of the big problems with current approaches,” says Aida.

This study was supported by the Hock E. Tan and K. Lisa Yang Center for Autism Research at MIT, the Poitras Center for Psychiatric Disorders Research at MIT, an NIH/NIMH Conte Center Grant, and the NIH Office of the Director.

Featured image: Staining for RAD51 (bright cyan-colored dot) in a fertilized one-cell mouse embryo shows repair of a CRISPR-induced DNA break. Credits: Image courtesy of the researchers.


Paper: “Efficient Homozygous Gene Conversion in Embryos via RAD51-Enhanced Interhomolog Repair”


Provided by MIT

CHIME Telescope Detects More Than 500 Mysterious Fast Radio Bursts in its First Year of Operation (Astronomy)

Observations quadruple the number of known radio bursts and reveal two types: one-offs and repeaters.

To catch sight of a fast radio burst is to be extremely lucky in where and when you point your radio dish. Fast radio bursts, or FRBs, are oddly bright flashes of light, registering in the radio band of the electromagnetic spectrum, that blaze for a few milliseconds before vanishing without a trace.

These brief and mysterious beacons have been spotted in various and distant parts of the universe, as well as in our own galaxy. Their origins are unknown, and their appearance is unpredictable. Since the first was discovered in 2007, radio astronomers have only caught sight of around 140 bursts in their scopes.

Now, a large stationary radio telescope in British Columbia has nearly quadrupled the number of fast radio bursts discovered to date. The telescope, known as CHIME, for the Canadian Hydrogen Intensity Mapping Experiment, has detected 535 new fast radio bursts during its first year of operation, between 2018 and 2019.

Scientists with the CHIME Collaboration, including researchers at MIT, have assembled the new signals in the telescope’s first FRB catalog, which they will present this week at the American Astronomical Society Meeting.

The new catalog significantly expands the current library of known FRBs, and is already yielding clues as to their properties. For instance, the newly discovered bursts appear to fall in two distinct classes: those that repeat, and those that don’t. Scientists identified 18 FRB sources that burst repeatedly, while the rest appear to be one-offs. The repeaters also look different, with each burst lasting slightly longer and emitting more focused radio frequencies than bursts from single, nonrepeating FRBs.

These observations strongly suggest that repeaters and one-offs arise from separate mechanisms and astrophysical sources. With more observations, astronomers hope soon to pin down the extreme origins of these curiously bright signals.

“Before CHIME, there were less than 100 total discovered FRBs; now, after one year of observation, we’ve discovered hundreds more,” says CHIME member Kaitlyn Shin, a graduate student in MIT’s Department of Physics. “With all these sources, we can really start getting a picture of what FRBs look like as a whole, what astrophysics might be driving these events, and how they can be used to study the universe going forward.”

Seeing flashes

CHIME comprises four massive cylindrical radio antennas, roughly the size and shape of snowboarding half-pipes, located at the Dominion Radio Astrophysical Observatory, operated by the National Research Council of Canada in British Columbia, Canada. CHIME is a stationary array, with no moving parts. The telescope receives radio signals each day from half of the sky as the Earth rotates.

A sky map of FRBs based on CHIME detections reveals bursts distributed evenly across the night sky. Credits:Image: Courtesy of CHIME

While most radio astronomy is done by swiveling a large dish to focus light from different parts of the sky, CHIME stares, motionless, at the sky, and focuses incoming signals using a correlator — a powerful digital signaling processor that can work through huge amounts of data, at a rate of about 7 terabits per second, equivalent to a few percent of the world’s internet traffic.

“Digital signal processing is what makes CHIME able to reconstruct and ‘look’ in thousands of directions simultaneously,” says Kiyoshi Masui, assistant professor of physics at MIT, who will lead the group’s conference presentation. “That’s what helps us detect FRBs a thousand times more often than a traditional telescope.”

Over the first year of operation, CHIME detected 535 new fast radio bursts. When the scientists mapped their locations, they found the bursts were evenly distributed in space, seeming to arise from any and all parts of the sky. From the FRBs that CHIME was able to detect, the scientists calculated that bright fast radio bursts occur at a rate of about 800 per day across the entire sky — the most precise estimate of FRBs overall rate to date.

“That’s kind of the beautiful thing about this field — FRBs are really hard to see, but they’re not uncommon,” says Masui, who is a member of MIT’s Kavli Institute for Astrophysics and Space Research. “If your eyes could see radio flashes the way you can see camera flashes, you would see them all the time if you just looked up.”

Mapping the universe

As radio waves travel across space, any interstellar gas, or plasma, along the way can distort or disperse the wave’s properties and trajectory. The degree to which a radio wave is dispersed can give clues to how much gas it passed through, and possibly how much distance it has traveled from its source.

For each of the 535 FRBs that CHIME detected, Masui and his colleagues measured its dispersion, and found that most bursts likely originated from far-off sources within distant galaxies. The fact that the bursts were bright enough to be detected by CHIME suggests that they must have been produced by extremely energetic sources. As the telescope detects more FRBs, scientists hope to pin down exactly what kind of exotic phenomena could generate such ultrabright, ultrafast signals.

Scientists also plan to use the bursts, and their dispersion estimates, to map the distribution of gas throughout the universe.

“Each FRB gives us some information of how far they’ve propagated and how much gas they’ve propagated through,” Shin says. “With large numbers of FRBs, we can hopefully figure out how gas and matter are distributed on very large scales in the universe. So, alongside the mystery of what FRBs are themselves, there’s also the exciting potential for FRBs as powerful cosmological probes in the future.”

This research was supported by various institutions including the Canada Foundation for Innovation, the Dunlap Institute for Astronomy and Astrophysics at the University of Toronto, the Canadian Institute for Advanced Research, McGill University and the McGill Space Institute via the Trottier Family Foundation, and the University of British Columbia.

Featured image: The large radio telescope CHIME, pictured here, has detected more than 500 mysterious fast radio bursts in its first year of operation, MIT researchers report. Credits:Image: Courtesy of CHIME


Provided by MIT

Asteroid 16 Psyche Might Not Be What Scientists Expected (Planetary Science)

New UArizona research finds that the target asteroid of NASA’s Psyche mission may not be as metallic or dense as previously predicted

The widely studied metallic asteroid known as 16 Psyche was long thought to be the exposed iron core of a small planet that failed to form during the earliest days of the solar system. But new University of Arizona-led research suggests that the asteroid might not be as metallic or dense as once thought, and hints at a much different origin story.

Scientists are interested in 16 Psyche because if its presumed origins are true, it would provide an opportunity to study an exposed planetary core up close. NASA is scheduled to launch its Psyche mission in 2022 and arrive at the asteroid in 2026.

UArizona undergraduate student David Cantillo is lead author of a new paper published in The Planetary Science Journal that proposes 16 Psyche is 82.5% metal, 7% low-iron pyroxene and 10.5% carbonaceous chondrite that was likely delivered by impacts from other asteroids. Cantillo and his collaborators estimate that 16 Psyche’s bulk density – also known as porosity, which refers to how much empty space is found within its body – is around 35%.

These estimates differ from past analyses of 16 Psyche’s composition that led researchers to estimate it could contain as much as 95% metal and be much denser.

“That drop in metallic content and bulk density is interesting because it shows that 16 Psyche is more modified than previously thought,” Cantillo said.

Rather than being an intact exposed core of an early planet, it might actually be closer to a rubble pile, similar to another thoroughly studied asteroid — Bennu. UArizona leads the science mission team for NASA’s OSIRIS-REx mission, which retrieved a sample from Bennu’s surface that is now making its way back to Earth.

“Psyche as a rubble pile would be very unexpected, but our data continues to show low-density estimates despite its high metallic content,” Cantillo said.

Asteroid 16 Psyche is about the size of Massachusetts, and scientists estimate it contains about 1% of all asteroid belt material. First spotted by an Italian astronomer in 1852, it was the 16th asteroid ever discovered.

“Having a lower metallic content than once thought means that the asteroid could have been exposed to collisions with asteroids containing the more common carbonaceous chondrites, which deposited a surface layer that we are observing,” Cantillo said. This was also observed on asteroid Vesta by the NASA Dawn spacecraft.

Asteroid 16 Psyche has been estimated to been worth $10,000 quadrillion (that’s $10,000 followed by 15 more zeroes), but the new findings could slightly devalue the iron-rich asteroid.

“This is the first paper to set some specific constraints on its surface content. Earlier estimates were a good start, but this refines those numbers a bit more,” Cantillo said.

The other well-studied asteroid, Bennu, contains a lot of carbonaceous chondrite material and has porosity of over 50%, which is a classic characteristic of a rubble pile.

Such high porosity is common for relatively small and low-mass objects such as Bennu – which is only as large as the Empire State Building – because a weak gravitational field prevents the object’s rocks and boulders from being packed together too tightly. But for an object the size of 16 Psyche to be so porous is unexpected.

“The opportunity to study an exposed core of a planetesimal is extremely rare, which is why they’re sending the spacecraft mission there,” Cantillo said, “but our work shows that 16 Psyche is a lot more interesting than expected.”

Past estimates of 16 Psyche’s composition were done by analyzing the sunlight reflected off its surface. The pattern of light matched that of other metallic objects. Cantillo and his collaborators instead recreated 16 Psyche’s regolith – or loose rocky surface material – by mixing different materials in a lab and analyzing light patterns until they matched telescope observations of the asteroid. There are only a few labs in the world practicing this technique, including the UArizona Lunar and Planetary Laboratory and the Johns Hopkins Applied Physics Laboratory in Maryland, where Cantillo worked while in high school.

“I’ve always been interested in space,” said Cantillo, who is also president of the UArizona Astronomy Club. “I knew that astronomy studies would be heavy on computers and observation, but I like to do more hands-on kind of work, so I wanted to connect my studies to geology somehow. I’m majoring geology and minoring in planetary science and math.”

“David’s paper is an example of the cutting-edge research work done by our undergraduate students,” said study co-author Vishnu Reddy, an associate professor of planetary sciences who heads up the lab in which Cantillo works. “It is also a fine example of the collaborative effort between undergraduates, graduate students, postdoctoral fellows and staff in my lab.”

The researchers also believe the carbonaceous material on 16 Psyche’s surface is rich in water, so they will next work to merge data from ground-based telescopes and spacecraft missions to other asteroids to help determine the amount of water present.


Reference: David C. Cantillo, Vishnu Reddy et al., “Constraining the Regolith Composition of Asteroid (16) Psyche via Laboratory Visible Near-infrared Spectroscopy”, The Planetary Science Journal, 2(3), 2021. Link to paper


Provided by University of Arizona

Scientists Identify Distinctive Deep Infrasound Rumbles of Space Launches (Astronomy)

Signatures of Space Shuttle, Falcon 9 rocket stages heard by international nuclear test monitoring system

After their initial blast, space rockets shoot away from the Earth with rumbles in infrasound, soundwaves too low to be heard by human ears that can travel thousands of miles.

New research used a system for monitoring nuclear tests to track the infrasound from 1,001 rocket launches. The research identified the distinctive sounds from seven different types of rockets, including the Space Shuttles, Falcon 9 rockets, various Soyuz rockets, the European Space Agency’s Ariane 5, Russian Protons and several types of Chinese Long March rockets.

In some cases, like the Space Shuttle and the Falcon 9, the researchers were also able to identify the various stages of the rockets’ journey.

The new information could be useful for finding problems and identifying the atmospheric re-entry or splashdown locations of rocket stages, according to the new study published in Geophysical Research Letters, AGU’s journal for high-impact, short-format reports with immediate implications spanning all Earth and space sciences.

Infrasound represents acoustic soundwaves below the general threshold of frequency that humans can hear. But while higher frequency noises are louder close to the source of things like nuclear explosions, low-frequency infrasound travels longer distances. Infrasound is produced by natural events as well as technological sources, and has been used to detect remote volcanic eruptions or the hum of the ocean swell.

To listen in on rocket launches, the authors tapped into a global monitoring network. After the United Nations General Assembly adopted the Comprehensive Nuclear-Test-Ban Treaty in 1996, scientists set up the International Monitoring System (IMS). This system is currently characterized by a series of 53 certified and operational infrasound stations around the world. Micro barometers at the IMS stations can detect the infrasound released by large nuclear explosions.

These stations also gather the infrasonic sounds released by other large explosions such as volcanic eruptions or space rocket launches. The researchers wanted to see if they could detect and characterize the launch of space rockets around the world.

They examined 7,637 infrasound signatures recorded at IMS stations from 2009 to mid-2020, a period that included 1,001 rocket launches. The team only examined rocket launches that occurred up to 5,000 kilometers from an IMS station, but found the acoustic signals from rocket launches could sometimes be detected up to 9,000 kilometers away, according to author Patrick Hupe, a researcher at the German Federal Institute for Geosciences and Natural Resources.

The researchers found infrasonic signatures for up to 73% of these rockets, or 733. The other 27% of launches they couldn’t detect because the rockets had smaller thrusts or the atmospheric conditions didn’t favor the propagation over long distances.

For the ones they did detect, they could determine the type of rockets launched, everything from the Space Shuttles, the last of which launched in 2011, to Russian Soyuz rockets. In total, they examined the signatures for seven rocket types to derive a relation between the measured amplitude and the rocket thrust: Space Shuttles; Falcon 9s; various Soyuz rockets; the European Space Agency’s Ariane 5; Russian Protons; Chinese Long March 2Cs, 2Ds, 3As, 4Bs, and 4Cs; and Long March 3Bs.

Space Shuttle vs Falcon 9

The researchers also took a closer look at two different rocket types – the Space Shuttle and the Falcon 9.

They found they could identify the infrasonic signals of various stages of flight for these rockets. For the first, a Space Shuttle launched from Kennedy Space Center in November 2009, the team detected the infrasound created by the splash down of the fuel boosters before they detected the acoustic signal of the initial rocket launch because they dropped down closer to the infrasound station than the launch site. In other words, the rocket was faster than sound.

“The rocket was faster than the infrasound propagated through the atmosphere,” Hupe said.

They also examined the launch and descent of SpaceX’s Falcon 9 rocket, which has a partially reusable rocket that reentered the atmosphere and landed successfully on a drone ship in the ocean in January 2020. Hupe’s team could detect both the takeoff of the rocket and the landing of the first booster.

“By processing the data and also applying different quality criteria to the infrasonic signatures we were able to separate different rocket stages,” Hupe said.

“The ability to detect different types of rockets could be helpful,” said Adrian Peter, a professor of computer engineering and sciences at the Florida Institute of Technology that wasn’t involved in Hupe’s work but who has studied the infrasonic signatures of rockets before.

He said the characterization of different stages of rocket launches could be useful for determining future problems. For example, if a rocket didn’t launch properly or exploded, researchers might be able to detect what went wrong by analyzing the infrasonic signature, especially when the information is correlated with sensor readings from the rockets themselves.

Peter adds that it’s great to see researchers harnessing the information gathered by a monitoring network that was initially only intended to watch for nuclear launches and explosions.

“Now we’re leveraging it for other scientific applications,” he said, adding that there are likely further uses for this type of data.

Featured image: Space Shuttle Atlantis mission STS-129 launches from NASA’s Kennedy Space Center in Florida on 16 November 2009. More than 900 miles away, the International Monitoring System infrasound station in Bermuda recorded infrasound from the launch and booster splashdown. Credit: NASA/Scott Andrews, Public domain, via Wikimedia Commons


Provided by AGU