SPACE
Auburn students gain career skills through space mission launch
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UNDERGRADUATE STUDENTS IN FOGLE'S CLASSROOM EXCITED TO GAIN LIFELONG CAREER SKILLS WITH SATELLITE MISSIONS.
view moreCREDIT: COLLEGE OF SCIENCES AND MATHEMATICS, AUBURN UNIVERSITY.
Auburn University students are acquiring essential workforce skills through an innovative initiative, supported by Firefly Aerospace's award to launch a mission aimed at addressing space debris mitigation.
Leading the Auburn project are Michael Fogle, the Howard Earl and Carolyn Taylor Carr Professor in the Department of Physics, and Mark Adams, the Godbold Associate Professor in Electrical and Computer Engineering. Fogle and Adams are the principal faculty mentors of the Auburn University Small Satellite Program (AUSSP), which currently has several other cubesat missions in the design phase and close to launch.
"This opportunity provides students with hands-on involvement in designing, constructing, testing, flying, and operating small satellites," stated Fogle, underscoring Auburn's commitment to delivering exceptional educational experiences.
Firefly’s Dedicated Research Education Accelerator Mission (DREAM) program has allocated excess capacity on its Alpha rocket to deploy cubesats or small satellites into low Earth orbit.
“These students are working to design and build an electrodynamic tether,” Fogle explained. “Think of a conducting ribbon or cable that moves through a magnetic field. An electrical current is induced. The resulting current moving through the magnetic field then experiences a force in the direction opposite the direction of motion of the satellite. This can help accelerate the ability to get these satellites out of orbit quicker and reduce the total amount of excess dead satellites that represent a debris risk to other missions.”
While historically, cubesats were designed to re-enter and burn up in Earth’s atmosphere after approximately 25 years, recent regulatory changes have shortened this timeline to five years. This project equips students with practical skills to address this pressing space debris issue.
The project targets a potential launch in 2025, with all work conducted on the Auburn University campus.
"Auburn University students will gain a diverse range of skills through this mission," Fogle noted. “This experience spans mechanical, thermal, electrical and software design as well as project management and systems engineering.”
"These skills are transferable across various career paths, enhancing their preparedness for future careers,” emphasized Fogle. "In addition to technical skills, students will develop soft skills critical for their professional journeys.”
"I am immensely proud that Auburn University students have the opportunity to lead a space mission," Fogle remarked. "This endeavor embodies Auburn's ethos, empowering students to participate in the DREAM program and cultivate skills necessary for impactful careers, both on Earth and beyond."
What are Hubble and Webb observing right now? NASA tool has the answer
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NASA’s Space Telescope Live, A WEB APPLICATION ORIGINALLY DEVELOPED IN 2016 TO DELIVER REAL-TIME UPDATES ON HUBBLE TARGETS, NOW AFFORDS EASY ACCESS TO UP-TO-DATE INFORMATION ON CURRENT, PAST, AND UPCOMING OBSERVATIONS FROM BOTH Hubble AND Webb.
view moreCREDIT: STSCI/NASA
It’s not hard to find out what NASA’s Hubble and James Webb space telescopes have observed in the past. Barely a week goes by without news of a cosmic discovery made possible using images, spectra, and other data captured by NASA’s prolific astronomical observatories.
But what are Hubble and Webb looking at right this minute? A shadowy pillar harboring nascent stars? A pair of colliding galaxies? The atmosphere of a distant planet? Galactic light, stretched and distorted on a 13-billion-year journey across space?
NASA’s Space Telescope Live, a web application originally developed in 2016 to deliver real-time updates on Hubble targets, now affords easy access to up-to-date information on current, past, and upcoming observations from both Hubble and Webb.
Designed and developed for NASA by the Space Telescope Science Institute in Baltimore, this exploratory tool offers the public a straightforward and engaging way to learn more about how astronomical investigations are carried out.
With its redesigned user interface and expanded functionality, users can find out not only what planet, star, nebula, galaxy, or region of deep space each telescope is observing at the moment, but also where exactly these targets are in the sky; what scientific instruments are being used to capture the images, spectra, and other data; precisely when and how long the observations are scheduled to occur; the status of the observation; who is leading the research; and most importantly, what the scientists are trying to find out.
Information for observations from approved science programs is available via the Mikulski Archive for Space Telescopes. NASA’s Space Telescope Live offers easy access to this information – not only the current day’s targets, but the entire catalog of past observations as well – with Webb records dating back to its first commissioning targets in January 2022, and Hubble records all the way back to the beginning of its operations in May 1990.
The zoomable sky map centered on the target’s location was developed using the Aladin Sky Atlas, with imagery from ground-based telescopes to provide context for the observation. (Because the Hubble and Webb data must go through preliminary processing, and in many cases preliminary analysis, before being released to the public and astronomy community, real-time imagery is not available in this tool for either telescope.)
Details such as target name and coordinates, scheduled start and end times, and the research topic, are pulled directly from the observation scheduling and proposal planning databases. Links within the tool direct users to the original research proposal, which serves as a gateway to more technical information.
While this latest version of NASA’s Space Telescope Live constitutes a significant transformation from the previous release, the team is already gathering feedback from users and planning additional enhancements to provide opportunities for deeper exploration and understanding.
NASA’s Space Telescope Live is designed to work on desktop and mobile devices, and is accessible via NASA’s official Hubble and Webb websites. Additional details about the content, including public-friendly explanations of the information displayed in the tool, can be found in the User Guide.
The James Webb Space Telescope is the world's premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. Goddard also conducts mission operations with Lockheed Martin Space in Denver, Colorado. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble and Webb science operations for NASA.
Webb Current Observations: https://science.nasa.gov/mission/webb/what-is-webb-observing/
Hubble Current Observations: https://science.nasa.gov/mission/hubble/multimedia/online-activities/what-is-hubble-observing/
UCF scientists use James Webb Space Telescope to uncover clues about Neptune’s evolution
Ana Carolina de Souza Feliciano and Noemí Pinilla-Alonso are part of a team that studies unique spectral properties of small celestial bodies beyond Neptune within the Kuiper Belt
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AN ARTIST’S CONCEPTION OF MORS-SOMNUS, A BINARY DUO COMPRISED OF A PAIR OF ICY ASTEROIDS BOUND BY GRAVITY, IS SHOWN. UCF RESEARCHERS RECENTLY USED THE JAMES WEBB SPACE TELESCOPE (ALSO DEPICTED) TO ANALYZE THEIR SURFACE COMPOSITIONS FOR THE FIRST TIME. IMAGE CREDIT: ANGELA RAMIREZ, UCF
view moreCREDIT: ANGELA RAMIREZ, UNIVERSITY OF CENTRAL FLORIDA
By Eddy Duryea
ORLANDO, March 6, 2024 – A ring of icy rocks orbiting our sun just beyond Neptune may give us a glimpse of how Neptune — and other objects in the outskirts of our solar system — were formed.
Mors-Somnus, a binary duo comprised of a pair of icy asteroids bound by gravity, was recently concluded to have originated within the Kuiper Belt, meaning it can serve as a basis to study and enrich our understanding of the dynamical history of Neptune and celestial bodies known as trans-Neptunian objects (TNOs).
The promising study, published recently in the journal Astronomy & Astrophysics, marks the first time this has been achieved and serves as a significant landmark for the UCF-led Discovering the Surface Compositions of Trans-Neptunian Objects program — or DiSCo-TNOs — which is part of the first cycle of the James Webb Space Telescope’s (JWST) many programs focused on analyzing our solar system.
Ana Carolina de Souza Feliciano and Noemí Pinilla-Alonso, a postdoctoral fellow and professor in planetary science at UCF’s Florida Space Institute respectively, are co-authors of the study and part of the DiSCo team that studies unique spectral properties of small celestial bodies beyond Neptune within the Kuiper Belt.
What is unique to this work is that it is possible to study the surface composition of two components of the binary pair of small-sized TNOs, which had never been done before and can have implications for how we understand the whole region beyond Neptune.
De Souza Feliciano led this particular study as part of Pinilla-Alonso’s greater DiSCo-TNOs program. The team used the JWST’s wide spectral capabilities to analyze the elemental composition of a half-dozen suspected closely related TNO surfaces to confirm that Mors-Somnus has much in common with its neighboring TNOs. These largely undisturbed TNOs are designated as “cold classical” and may serve as points of reference where Neptune didn’t disturb them during its migration.
Together, the binary objects and other nearby TNOs in the same dynamical group can act as an indicator to potentially track Neptune’s migration before it settled into its final orbit, the researchers say.
Binaries separated by distance, as Mors-Somnus is, rarely survive outside of areas bound by gravity and sheltered by other flecks of ice and rock such as the Kuiper Belt. To survive implantation in such areas, they require a slow transportation process toward their destination.
Due to the similar spectroscopic behavior of Mors and Somnus and their similarities with the cold-classical group, the researchers found compositional evidence for the formation of this binary pair beyond 30 astronomical units (nearly 2.7 billion miles away), as is also hypothesized in the previously published literature for the region where the cold-classic TNOs are also formed.
The steady stream of discoveries such as this were somewhat expected, as the first data from the DiSCo-TNOs studies on nearly 60 TNOs began to trickle in as early late 2022.
“As we started to analyze the Mors and Somnus spectra, more data were arriving, and the connection between the dynamic groups and compositional behavior was natural,” de Souza Feliciano says.
More specifically, studying the composition of small celestial bodies such as Mors-Somnus gives us precious information about where we came from, Pinilla-Alonso says.
“We are studying how the actual chemistry and physics of the TNOs reflect the distribution of molecules based on carbon, oxygen, nitrogen and hydrogen in the cloud that gave birth to the planets, their moons, and the small bodies,” she says. “These molecules were also the origin of life and water on Earth.”
However, she says there still remains great opportunity to advance our knowledge of the history of the Trans-Neptunian region with the unprecedented spectral powers of JWST.
“For the first time, we can not only resolve images of systems with multiple components like the Hubble Space Telescope, but we can also study their composition with a level of detail that only Webb can provide,” Pinilla-Alonso says. “We can now investigate the formation process of these binaries like never before.”
Although Pinilla-Alonso conceived the DiSCo-TNOs program, she trusts her colleagues such as de Souza Feliciano to decipher the findings and generate valuable research.
“I am proud to have played a role in providing the necessary data and support to (Ana) Carol(olina), a brilliant UCF postdoctoral researcher who has been the true leader of this work,” Pinilla-Alonso says. “With the Webb telescope set to last for decades, this is an amazing opportunity for the next generation of researchers to step up and lead their science projects.”
Being a trailblazer for such incredible discoveries truly is exciting, de Souza Feliciano adds.
“Before JWST, there was no instrument able to obtain information from these objects in that wavelength range,” she says. “I feel happy to be able to participate in the era inaugurated by the JWST.”
Researchers’ Credentials
De Souza Feliciano received her doctorate in astronomy from Observatório Nacional de Rio de Janeiro, Brazil and is part of UCF’s Preeminent Postdoctoral Program. She works under the supervision of Pinilla-Alonso on the DiSCo-TNOs program.
Pinilla-Alonso is a professor at the Florida Space Institute and joined UCF in 2015. She received her doctorate in astrophysics and planetary sciences from the Universidad de La Laguna in Spain. Pinilla-Alonso also holds a joint appointment as a professor in UCF’s Department of Physics and has led numerous international observational campaigns in support of NASA missions such as New Horizons, OSIRIS-ReX and Lucy.
CONTACT: Robert H. Wells, Office of Research, robert.wells@ucf.edu
JOURNAL
Astronomy and Astrophysics
METHOD OF RESEARCH
Observational study
ARTICLE TITLE
Spectroscopy of the binary TNO Mors–Somnus with the JWST and its relationship to the cold classical and plutino subpopulations observed in the DiSCo-TNO project
Webb unlocks secrets of one of the most distant galaxies ever seen
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THIS IMAGE FROM NASA’S JAMES WEBB SPACE TELESCOPE NIRCAM (NEAR-INFRARED CAMERA) INSTRUMENT SHOWS A PORTION OF THE GOODS-NORTH FIELD OF GALAXIES. AT LOWER RIGHT, A PULLOUT HIGHLIGHTS THE GALAXY GN-Z11, WHICH IS SEEN AT A TIME JUST 430 MILLION YEARS AFTER THE BIG BANG. THE IMAGE REVEALS AN EXTENDED COMPONENT, TRACING THE GN-Z11 HOST GALAXY, AND A CENTRAL COMPACT SOURCE WHOSE COLORS ARE CONSISTENT WITH THOSE OF AN ACCRETION DISK SURROUNDING A BLACK HOLE.
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CREDIT: NASA, ESA, CSA, BRANT ROBERTSON (UC SANTA CRUZ), BEN JOHNSON (CFA), SANDRO TACCHELLA (CAMBRIDGE), MARCIA RIEKE (UNIVERSITY OF ARIZONA), DANIEL EISENSTEIN (CFA)
Looking deeply into space and time, two teams using NASA’s James Webb Space Telescope have studied the exceptionally luminous galaxy GN-z11, which existed when our 13.8 billion-year-old universe was only about 430 million years old.
Initially detected with NASA’s Hubble Space Telescope, this galaxy — one of the youngest and most distant ever observed — is so bright that it is challenging scientists to understand why. Now, GN-z11 is giving up some of its secrets.
Vigorous Black Hole Is Most Distant Ever Found
A team studying GN-z11 with Webb found the first clear evidence that the galaxy is hosting a central, supermassive black hole that is rapidly accreting matter. Their finding makes this the farthest active supermassive black hole spotted to date.
“We found extremely dense gas that is common in the vicinity of supermassive black holes accreting gas,” explained principal investigator Roberto Maiolino of the Cavendish Laboratory and the Kavli Institute of Cosmology at the University of Cambridge in the United Kingdom. “These were the first clear signatures that GN-z11 is hosting a black hole that is gobbling matter.”
Using Webb, the team also found indications of ionized chemical elements typically observed near accreting supermassive black holes. Additionally, they discovered a very powerful wind being expelled by the galaxy. Such high-velocity winds are typically driven by processes associated with vigorously accreting supermassive black holes.
“Webb’s NIRCam (Near-Infrared Camera) has revealed an extended component, tracing the host galaxy, and a central, compact source whose colors are consistent with those of an accretion disk surrounding a black hole,” said investigator Hannah Übler, also of the Cavendish Laboratory and the Kavli Institute.
Together, this evidence shows that GN-z11 hosts a 2-million-solar-mass, supermassive black hole in a very active phase of consuming matter, which is why it's so luminous.
Pristine Gas Clump in GN-z11’s Halo Intrigues Researchers
A second team, also led by Maiolino, used Webb’s NIRSpec (Near-Infrared Spectrograph) to find a gaseous clump of helium in the halo surrounding GN-z11.
“The fact that we don't see anything else beyond helium suggests that this clump must be fairly pristine,” said Maiolino. “This is something that was expected by theory and simulations in the vicinity of particularly massive galaxies from these epochs — that there should be pockets of pristine gas surviving in the halo, and these may collapse and form Population III star clusters.”
Finding the never-before-seen Population III stars — the first generation of stars formed almost entirely from hydrogen and helium — is one of the most important goals of modern astrophysics. These stars are anticipated to be very massive, very luminous, and very hot. Their expected signature is the presence of ionized helium and the absence of chemical elements heavier than helium.
The formation of the first stars and galaxies marks a fundamental shift in cosmic history, during which the universe evolved from a dark and relatively simple state into the highly structured and complex environment we see today.
In future Webb observations, Maiolino, Übler, and their team will explore GN-z11 in greater depth, and they hope to strengthen the case for the Population III stars that may be forming in its halo.
The research on the pristine gas clump in GN-z11’s halo has been accepted for publication by Astronomy & Astrophysics. The results of the study of GN-z11’s black hole were published in the journal Nature on January 17, 2024. The data was obtained as part of the JWST Advanced Deep Extragalactic Survey (JADES), a joint project between the NIRCam and NIRSpec teams.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
This two-part graphic shows evidence of a gaseous clump of helium in the halo surrounding galaxy GN-z11. In the top portion, at the far right, a small box identifies GN-z11 in a field of galaxies. The middle box shows a zoomed-in image of the galaxy. The box at the far left displays a map of the helium gas in the halo of GN-z11, including a clump that does not appear in the infrared colors shown in the middle panel. In the lower half of the graphic, a spectrum shows the distinct “fingerprint” of helium in the halo. The full spectrum shows no evidence of other elements and so suggests that the helium clump must be fairly pristine, made of hydrogen and helium gas left over from the big bang, without much contamination from heavier elements produced by stars. Theory and simulations in the vicinity of particularly massive galaxies from these epochs predict that there should be pockets of pristine gas surviving in the halo, and these may collapse and form Population III star clusters.
CREDIT
NASA, ESA, CSA, Ralf Crawford (STScI)
JOURNAL
Nature
ARTICLE TITLE
A small and vigorous black hole in the early Universe
Can artificial intelligence–based systems spot hard-to-detect space debris?
Peer-Reviewed Publication
An increasing number of space objects, debris, and satellites in Low Earth Orbit poses a significant threat of collisions during space operations. The situation is currently monitored by radar and radio-telescopes that track space objects, but much of space debris is composed of very small metallic objects that are difficult to detect. In a study published in IET Radar, Sonar & Navigation, investigators demonstrate the benefits of using deep learning—a form of artificial intelligence—for small space object detection by radar.
The team modelled a prominent radar system in Europe (called Tracking and Imaging Radar) in tracking mode to produce training and testing data. Then, the group compared classical detection systems with a You-Only-Look-Once (YOLO)–based detector. (YOLO is a popular object detection algorithm that has been widely used in computer vision applications.) An evaluation in a simulated environment demonstrated that YOLO-based detection outperforms conventional approaches, guaranteeing a high detection rate while keeping false alarm rates low.
“In addition to improving space surveillance capabilities, artificial intelligence–based systems like YOLO have the potential to revolutionize space debris management,” said co–corresponding author Federica Massimi, PhD, of Roma Tre University, in Italy. “By quickly identifying and tracking hard-to-detect objects, these systems enable proactive decision-making and intervention strategies to mitigate collisions and risks and preserve the integrity of critical space resources.”
URL upon publication: https://onlinelibrary.wiley.com/doi/10.1049/rsn2.12547
Additional Information
NOTE: The information contained in this release is protected by copyright. Please include journal attribution in all coverage. For more information or to obtain a PDF of any study, please contact: Sara Henning-Stout, newsroom@wiley.com.
About the Journal
IET Radar, Sonar & Navigation is a fully open access distinguished journal that covers the theory and practice of systems and signals for radar, sonar, radiolocation, navigation and surveillance purposes, in aerospace and terrestrial applications.
About Wiley
Wiley is a knowledge company and a global leader in research, publishing, and knowledge solutions. Dedicated to the creation and application of knowledge, Wiley serves the world’s researchers, learners, innovators, and leaders, helping them achieve their goals and solve the world's most important challenges. For more than two centuries, Wiley has been delivering on its timeless mission to unlock human potential. Visit us at Wiley.com. Follow us on Facebook, Twitter, LinkedIn and Instagram.
An increasing number of space objects, debris, and satellites in Low Earth Orbit poses a significant threat of collisions during space operations. The situation is currently monitored by radar and radio-telescopes that track space objects, but much of space debris is composed of very small metallic objects that are difficult to detect. In a study published in IET Radar, Sonar & Navigation, investigators demonstrate the benefits of using deep learning—a form of artificial intelligence—for small space object detection by radar.
The team modelled a prominent radar system in Europe (called Tracking and Imaging Radar) in tracking mode to produce training and testing data. Then, the group compared classical detection systems with a You-Only-Look-Once (YOLO)–based detector. (YOLO is a popular object detection algorithm that has been widely used in computer vision applications.) An evaluation in a simulated environment demonstrated that YOLO-based detection outperforms conventional approaches, guaranteeing a high detection rate while keeping false alarm rates low.
“In addition to improving space surveillance capabilities, artificial intelligence–based systems like YOLO have the potential to revolutionize space debris management,” said co–corresponding author Federica Massimi, PhD, of Roma Tre University, in Italy. “By quickly identifying and tracking hard-to-detect objects, these systems enable proactive decision-making and intervention strategies to mitigate collisions and risks and preserve the integrity of critical space resources.”
URL upon publication: https://onlinelibrary.wiley.com/doi/10.1049/rsn2.12547
Additional Information
NOTE: The information contained in this release is protected by copyright. Please include journal attribution in all coverage. For more information or to obtain a PDF of any study, please contact: Sara Henning-Stout, newsroom@wiley.com.
About the Journal
IET Radar, Sonar & Navigation is a fully open access distinguished journal that covers the theory and practice of systems and signals for radar, sonar, radiolocation, navigation and surveillance purposes, in aerospace and terrestrial applications.
About Wiley
Wiley is a knowledge company and a global leader in research, publishing, and knowledge solutions. Dedicated to the creation and application of knowledge, Wiley serves the world’s researchers, learners, innovators, and leaders, helping them achieve their goals and solve the world's most important challenges. For more than two centuries, Wiley has been delivering on its timeless mission to unlock human potential. Visit us at Wiley.com. Follow us on Facebook, Twitter, LinkedIn and Instagram.
JOURNAL
IET Radar Sonar & Navigation
IET Radar Sonar & Navigation
DOI
ARTICLE TITLE
Deep Learning-based Space Debris Detection for SSA: a feasibility study applied to the radar processing
Deep Learning-based Space Debris Detection for SSA: a feasibility study applied to the radar processing
ARTICLE PUBLICATION DATE
6-Mar-2024
6-Mar-2024
From Tatooine to reality
Exoplanets' role in shaping science fiction
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IMAGE RELABORATED FROM CANVA PREMIUM LIBRARIES - ROYALTY FREE
view moreCREDIT: JOURNAL OF SCIENCE COMMUNICATION - JCOM
An astronomy lesson on binary stars could begin with a series of complex diagrams and data, or with a clip from the movie Star Wars where Luke Skywalker looks up at the sky of his home planet, Tatooine, and sees two suns shining. Which will more easily awaken the interest of a sleepy high school class? Science fiction has always captured our attention, and as many scientists claim, it has often been a source of inspiration for their scientific careers. For this reason, it is sometimes used to communicate science to the public, even conveying complex content. To be sure that this is an effective method, it is necessary to understand how actual science is represented by science fiction. This is what a new paper published in the Journal of Science Communication - JCOM has done, using a quantitative methodology capable of analyzing a large corpus of science fiction works (specifically addressing exoplanets), showing that significant changes in scientific knowledge correspond to changes in science fiction literature as well.
Emma Johanna Puranen, a researcher at the St Andrews Centre for Exoplanet Science (University of St Andrews), along with her colleagues at the Centre, Emily Finer and V Anne Smith, and Christiane Helling, Director of the Space Research Institute (IWF) of the Austrian Academy of Sciences, have applied Bayesian network analysis to a corpus of 142 science fiction works, including novels, films, television programs, podcasts, and video games. For their research, the scientists chose to investigate the representation of extrasolar planets, also called exoplanets. “They're sort of ubiquitous in science fiction. They're everywhere. Most stories that are set in space will eventually have a scene on an exoplanet,” explains Puranen. “The other reason for using exoplanets is that there was a huge shift in our scientific understanding in 1995 when the first exoplanet around a sun-like star was discovered.”
The Bayesian network methodology allowed for quantitative investigation of a subject matter—science fiction—usually analyzed qualitatively, and often only one work at a time. In a Bayesian network, the characteristics of the exoplanets portrayed in the selected works are represented as nodes in an interconnected network, allowing us to understand how each node affects the others. In practice, it can be determined if, for example, a planet in a specific work is represented as favourable to life, whether and how strongly that influences another characteristic. Since the science fiction works analyzed were distributed over a relatively wide time span, before and after 1995, Puranen and colleagues were able to observe that after that date, the representation of exoplanets in science fiction changed.
“Traditionally in science fiction, there have been a high proportion of Earth-like and habitable planets,” explains Puranen, and this is obviously sensible, since these are cultural products made by humans for other humans. “but what has changed since the discovery of real exoplanets is that the fictional exoplanets have actually become a bit less Earth-like.”
Indeed, the large numbers of exoplanets actually observed by science to date contains a vast majority of planets very different from ours, and very rarely positioned in what scientists define as the habitable zone, where conditions are potentially friendlier to life as we know it. This scientific reality, comments Puranen, has percolated into science fiction representation. “I can speculate that maybe authors of science fiction are reading all these headlines about worlds that are covered in lava or where it's raining diamonds, which you see in the media,” comments the researcher.
“I do think science fiction is responsive to discoveries in science. I think it's sort of reflective of what was going on in science at the time that it was written,” concludes Puranen. “So I do think it could be incorporated into science communication in terms of providing a jumping-off point. It can introduce concepts to people.”
The paper “Science Fiction Media Representations of Exoplanets: Portrayals of Changing Astronomical Discoveries” can be read for free on JCOM.
JOURNAL
Journal of Science Communication
METHOD OF RESEARCH
Data/statistical analysis
ARTICLE TITLE
Science fiction media representations of exoplanets: portrayals of changing astronomical discoveries
ARTICLE PUBLICATION DATE
4-Mar-2024
Astronomers spot oldest ‘dead’ galaxy yet observed
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FALSE-COLOUR JWST IMAGE OF A SMALL FRACTION OF THE GOODS SOUTH FIELD, WITH JADES-GS-Z7-01-QU HIGHLIGHTED. THIS KIND OF GALAXY IS EXTREMELY RARE
view moreCREDIT: JADES COLLABORATION
A galaxy that suddenly stopped forming new stars more than 13 billion years ago has been observed by astronomers.
Using the James Webb Space Telescope, an international team of astronomers led by the University of Cambridge have spotted a ‘dead’ galaxy when the universe was just 700 million years old, the oldest such galaxy ever observed.
This galaxy appears to have lived fast and died young: star formation happened quickly and stopped almost as quickly, which is unexpected for so early in the universe’s evolution. However, it is unclear whether this galaxy’s ‘quenched’ state is temporary or permanent, and what caused it to stop forming new stars.
The results, reported in the journal Nature, could be important to help astronomers understand how and why galaxies stop forming new stars, and whether the factors affecting star formation have changed over billions of years.
“The first few hundred million years of the universe was a very active phase, with lots of gas clouds collapsing to form new stars,” said Tobias Looser from the Kavli Institute for Cosmology, the paper’s first author. “Galaxies need a rich supply of gas to form new stars, and the early universe was like an all-you-can-eat buffet.”
“It’s only later in the universe that we start to see galaxies stop forming stars, whether that’s due to a black hole or something else,” said co-author Dr Francesco D’Eugenio, also from the Kavli Institute for Cosmology.
Astronomers believe that star formation can be slowed or stopped by different factors, all of which will starve a galaxy of the gas it needs to form new stars. Internal factors, such as a supermassive black hole or feedback from star formation, can push gas out of the galaxy, causing star formation to stop rapidly. Alternatively, gas can be consumed very quickly by star formation, without being promptly replenished by fresh gas from the surroundings of the galaxy, resulting in galaxy starvation.
“We’re not sure if any of those scenarios can explain what we’ve now seen with Webb,” said co-author Professor Roberto Maiolino. “Until now, to understand the early universe, we’ve used models based on the modern universe. But now that we can see so much further back in time, and observe that the star formation was quenched so rapidly in this galaxy, models based on the modern universe may need to be revisited.”
Using data from JADES (JWST Advanced Deep Extragalactic Survey), the astronomers determined that this galaxy experienced a short and intense period of star formation over a period between 30 and 90 million years. But between 10 and 20 million years before the point in time where it was observed with Webb, star formation suddenly stopped.
“Everything seems to happen faster and more dramatically in the early universe, and that might include galaxies moving from a star-forming phase to dormant or quenched,” said Looser.
Astronomers have previously observed dead galaxies in the early universe, but this galaxy is the oldest yet – just 700 million years after the big bang, more than 13 billion years ago. This observation is one of the deepest yet made with Webb.
In addition to the oldest, this galaxy is also relatively low mass – about the same as the Small Magellanic Cloud (SMC), a dwarf galaxy near the Milky Way, although the SMC is still forming new stars. Other quenched galaxies in the early universe have been far more massive, but Webb’s improved sensitivity allows smaller and fainter galaxies to be observed and analysed.
The astronomers say that although it appears dead at the time of observation, it’s possible that in the roughly 13 billion years since, this galaxy may have come back to life and started forming new stars again.
“We’re looking for other galaxies like this one in the early universe, which will help us place some constraints on how and why galaxies stop forming new stars,” said D’Eugenio. “It could be the case that galaxies in the early universe ‘die’ and then burst back to life – we’ll need more observations to help us figure that out.”
The research was supported in part by the European Research Council, the Royal Society, and the Science and Technology Facilities Council (STFC), part of UK Research and Innovation (UKRI).
JOURNAL
Nature
ARTICLE TITLE
A recently quenched galaxy 700 million years after the Big Bang
ARTICLE PUBLICATION DATE
6-Mar-2024
Discovery tests theory on cooling of white dwarf stars
IMAGE:
ALL SKY VIEW OF THE MILKY WAY TAKEN BY THE EUROPEAN SPACE AGENCY'S GAIA SPACE OBSERVATORY.
CREDIT: ESA/GAIA/DPAC, CC BY SA 3.0 IGO
view moreCREDIT: ALL SKY VIEW OF THE MILKY WAY TAKEN BY THE EUROPEAN SPACE AGENCY'S GAIA SPACE OBSERVATORY CREDIT: ESA/GAIA/DPAC, CC BY SA 3.0 IGO
Open any astronomy textbook to the section on white dwarf stars and you’ll likely learn that they are “dead stars” that continuously cool down over time. New research published in Nature is challenging this theory, with the University of Victoria (UVic) and its partners using data from the European Space Agency’s Gaia satellite to reveal why a population of white dwarf stars stopped cooling for more than eight billion years.
“We discovered the classical picture of all white dwarfs being dead stars is incomplete,” says Simon Blouin, co-principal investigator and Canadian Institute of Theoretical Astrophysics National Fellow at UVic. “For these white dwarfs to stop cooling, they must have some way of generating extra energy. We weren’t sure how this was happening, but now we have an explanation for the phenomenon.”
Understanding the age and other aspects of white dwarf stars helps scientists reconstruct the formation of the Milky Way Galaxy. Using 2019 Gaia data, Blouin collaborated with Antoine Bédard of the University of Warwick and Institute for Advanced Study researcher Sihao Cheng to make the discovery.
Over 97 per cent of stars in the Milky Way will eventually become white dwarfs. Scientists have long considered these stars to be at the end of their lives. Having depleted their nuclear energy source, they stop producing heat and cool down until the dense plasma in their interiors freezes into a solid state, and the star solidifies from the inside out. This cooling process can take billions of years.
According to the new paper, in some white dwarfs, the dense plasma in the interior does not simply freeze from the inside out. Instead, the solid crystals that are formed upon freezing are less dense than the liquid, and therefore want to float. As the crystals float upwards, they displace the heavier liquid downward. The transport of heavier material toward the centre of the star releases gravitational energy, and this energy is enough to interrupt the star’s cooling process for billions of years.
“This is the first time this transport mechanism has been observed in any type of star, which is exciting, as it is not every day we uncover a whole new astrophysical phenomenon,” says Bédard, Research Fellow at the University of Warwick.
Why this happens in some stars and not others is uncertain, but Blouin thinks it is likely due to the composition of the star.
“Some white dwarf stars are formed by the merger of two different stars. When these stars collide to form the white dwarf, it changes the composition of the star in a way that can allow the formation of floating crystals,” says Blouin.
White dwarfs are routinely used as age indicators: the cooler a white dwarf is, the older it is assumed to be. However, due to the extra delay in cooling found in some white dwarfs, some stars of a given temperature may be billions of years older than previously thought.
“This new discovery will not only require that astronomy textbooks be revised but will also require that astronomers revisit the process they use to determine the age of stellar populations,” adds Blouin.
The research is supported by the National Sciences and Engineering Research Council of Canada (NSERC), the Banting Postdoctoral Fellowship program, the European Research Council, and the Canadian Institute for Theoretical Astrophysics (CITA).
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JOURNAL
Nature
ARTICLE TITLE
Buoyant crystals halt the cooling of white dwarf stars
ARTICLE PUBLICATION DATE
6-Mar-2024
New theory explains why white dwarf stars can cheat death
IMAGE:
REPRESENTATION OF WHITE DWARF STAR V391 PEG
view moreCREDIT: CHRIS LAUREL, CELESTIA
In a paper published today in Nature, scholars from the Institute for Advanced Study; the University of Victoria, Canada; and the University of Warwick, U.K., have proposed a new theory that explains why a puzzling population of white dwarf stars stopped cooling for ten billion years.
Open any astronomy textbook to the section on white dwarf stars and you’ll likely learn that they are "dead stars" that continuously cool down over time. The cooling occurs because the white dwarfs have depleted their nuclear heat source. In the classic picture, this causes the dense plasma in a white dwarf’s interior to freeze, leading the star to solidify from the inside out.
However, an analysis of data from the European Space Agency’s Gaia satellite, published in 2019 by Sihao Cheng, Martin A. and Helen Chooljian Member in the Institute’s School of Natural Sciences, contradicted this standard picture. It showed that some white dwarfs in fact remain hot for many billions of years (a large portion of the age of the Universe). This finding had confounded theorists, but today’s new paper might provide a compelling explanation.
"In order for these white dwarfs to cease cooling down, they must somehow produce additional energy," says Cheng, who also contributed to the Nature paper. "Although we were initially uncertain about what this process might be, we now have a clearer understanding of how it occurs."
This understanding was developed through a collaboration between Cheng, Antoine Bédard of the University of Warwick, and Simon Blouin of the University of Victoria.
They propose that in some white dwarfs, the dense plasma in the interior does not simply freeze from the inside out. Instead, the solid crystals that are formed upon freezing are less dense than the liquid, and therefore begin to float towards the surface. As the crystals float upwards, they displace the heavier liquid downward. The transport of denser material toward the center of the star releases gravitational energy, and this energy is enough to interrupt the star’s cooling process for billions of years.
"One fascinating aspect of this discovery is that the physics involved is similar to something we observe in daily life: the frozen crystals within the white dwarf star float instead of sink. We might compare their behavior to ice cubes floating in water," says Cheng.
Why this happens in some white dwarfs and not others is uncertain, but the authors think it is likely due to the composition of the star.
"Some white dwarf stars are formed by the merger of two different stars. When these stars collide to form the white dwarf, it changes the composition of the star in a way that can allow the formation of floating crystals," says Blouin.
White dwarfs are routinely used as age indicators: the cooler a white dwarf is, the older it is assumed to be. However, due to the extra delay in cooling found in some white dwarfs, some stars of a given temperature may be billions of years older than previously thought. Better understanding the ages and other aspects of white dwarf stars will help scientists reconstruct the formation of our galaxy.
"Our work will necessitate updates to astronomy textbooks," adds Cheng. "We hope that it will also prompt astronomers to reassess the methods employed to calculate the age of stellar populations."
The research is supported by the National Sciences and Engineering Research Council of Canada (NSERC), the Banting Postdoctoral Fellowship program, the European Research Council, the Canadian Institute for Theoretical Astrophysics (CITA), and the Institute for Advanced Study's Fund for Natural Sciences.
This news is adapted from a press release issued by the University of Victoria (UVic). Press releases were also produced by CITA and by the University of Warwick.
About the Institute
The Institute for Advanced Study has served the world as one of the leading independent centers for theoretical research and intellectual inquiry since its establishment in 1930, advancing the frontiers of knowledge across the sciences and humanities. From the work of founding IAS faculty such as Albert Einstein and John von Neumann to that of the foremost thinkers of the present, the IAS is dedicated to enabling curiosity-driven exploration and fundamental discovery.
Each year, the Institute welcomes more than 200 of the world’s most promising post-doctoral researchers and scholars who are selected and mentored by a permanent Faculty, each of whom are preeminent leaders in their fields. Among present and past Faculty and Members there have been 35 Nobel Laureates, 44 of the 62 Fields Medalists, and 23 of the 26 Abel Prize Laureates, as well as many MacArthur Fellows and Wolf Prize winners.
JOURNAL
Nature
ARTICLE TITLE
Buoyant crystals halt the cooling of white dwarf stars
ARTICLE PUBLICATION DATE
6-Mar-2024
Groundbreaking survey reveals secrets of planet birth around dozens of stars
IMAGE:
THIS RESEARCH BRINGS TOGETHER OBSERVATIONS OF MORE THAN 80 YOUNG STARS THAT MIGHT HAVE PLANETS FORMING AROUND THEM IN SPECTACULAR DISCS. THIS SMALL SELECTION FROM THE SURVEY SHOWS 10 DISCS FROM THE THREE REGIONS OF OUR GALAXY OBSERVED IN THE PAPERS. V351 ORI AND V1012 ORI ARE LOCATED IN THE MOST DISTANT OF THE THREE REGIONS, THE GAS-RICH CLOUD OF ORION, SOME 1600 LIGHT-YEARS FROM EARTH. DG TAU, T TAU, HP TAU, MWC758 AND GM AUR ARE LOCATED IN THE TAURUS REGION, WHILE HD 97048, WW CHA AND SZ CHA CAN BE FOUND IN CHAMAELEON I, ALL OF WHICH ARE ABOUT 600 LIGHT-YEARS FROM EARTH.
THE IMAGES SHOWN HERE WERE CAPTURED USING THE SPECTRO-POLARIMETRIC HIGH-CONTRAST EXOPLANET RESEARCH (SPHERE) INSTRUMENT MOUNTED ON ESO’S VERY LARGE TELESCOPE (VLT). SPHERE’S STATE-OF-THE-ART EXTREME adaptive optics SYSTEM CORRECTS FOR THE TURBULENT EFFECTS OF EARTH’S ATMOSPHERE, YIELDING CRISP IMAGES OF THE DISCS AROUND STARS. THE STARS THEMSELVES HAVE BEEN COVERED WITH A CORONAGRAPH –– A CIRCULAR MASK THAT BLOCKS THEIR INTENSE GLARE, REVEALING THE FAINT DISCS AROUND THEM.
THE DISCS HAVE BEEN SCALED TO APPEAR ROUGHLY THE SAME SIZE IN THIS COMPOSITION.
view moreCREDIT: ESO/C. GINSKI, A. GARUFI, P.-G. VALEGÅRD ET AL.
In a series of studies, a team of astronomers has shed new light on the fascinating and complex process of planet formation. The stunning images, captured using the European Southern Observatory's Very Large Telescope (ESO’s VLT) in Chile, represent one of the largest ever surveys of planet-forming discs. The research brings together observations of more than 80 young stars that might have planets forming around them, providing astronomers with a wealth of data and unique insights into how planets arise in different regions of our galaxy.
“This is really a shift in our field of study,” says Christian Ginski, a lecturer at the University of Galway, Ireland, and lead author of one of three new papers published today in Astronomy & Astrophysics. “We’ve gone from the intense study of individual star systems to this huge overview of entire star-forming regions.”
To date more than 5000 planets have been discovered orbiting stars other than the Sun, often within systems markedly different from our own Solar System. To understand where and how this diversity arises, astronomers must observe the dust- and gas-rich discs that envelop young stars — the very cradles of planet formation. These are best found in huge gas clouds where the stars themselves are forming.
Much like mature planetary systems, the new images showcase the extraordinary diversity of planet-forming discs. “Some of these discs show huge spiral arms, presumably driven by the intricate ballet of orbiting planets,” says Ginski. “Others show rings and large cavities carved out by forming planets, while yet others seem smooth and almost dormant among all this bustle of activity,” adds Antonio Garufi, an astronomer at the Arcetri Astrophysical Observatory, Italian National Institute for Astrophysics (INAF), and lead author of one of the papers.
The team studied a total of 86 stars across three different star-forming regions of our galaxy: Taurus and Chamaeleon I, both around 600 light-years from Earth, and Orion, a gas-rich cloud about 1600 light-years from us that is known to be the birthplace of several stars more massive than the Sun. The observations were gathered by a large international team, comprising scientists from more than 10 countries.
The team was able to glean several key insights from the dataset. For example, in Orion they found that stars in groups of two or more were less likely to have large planet-forming discs. This is a significant result given that, unlike our Sun, most stars in our galaxy have companions. As well as this, the uneven appearance of the discs in this region suggests the possibility of massive planets embedded within them, which could be causing the discs to warp and become misaligned.
While planet-forming discs can extend for distances hundreds of times greater than the distance between Earth and the Sun, their location several hundreds of light-years from us makes them appear as tiny pinpricks in the night sky. To observe the discs, the team employed the sophisticated Spectro-Polarimetric High-contrast Exoplanet REsearch instrument (SPHERE) mounted on ESO’s VLT. SPHERE’s state-of-the-art extreme adaptive optics system corrects for the turbulent effects of Earth’s atmosphere, yielding crisp images of the discs. This meant the team were able to image discs around stars with masses as low as half the mass of the Sun, which are typically too faint for most other instruments available today. Additional data for the survey were obtained using the VLT’s X-shooter instrument, which allowed astronomers to determine how young and how massive the stars are. The Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, on the other hand, helped the team understand more about the amount of dust surrounding some of the stars.
As technology advances, the team hopes to delve even deeper into the heart of planet-forming systems. The large 39-metre mirror of ESO’s forthcoming Extremely Large Telescope (ELT), for example, will enable the team to study the innermost regions around young stars, where rocky planets like our own might be forming.
For now, these spectacular images provide researchers with a treasure trove of data to help unpick the mysteries of planet formation. “It is almost poetic that the processes that mark the start of the journey towards forming planets and ultimately life in our own Solar System should be so beautiful,” concludes Per-Gunnar Valegård, a doctoral student at the University of Amsterdam, the Netherlands, who led the Orion study. Valegård, who is also a part-time teacher at the International School Hilversum in the Netherlands, hopes the images will inspire his pupils to become scientists in the future.
More information
This research was presented in three papers to appear in Astronomy & Astrophysics. The data presented were gathered as part of the SPHERE consortium guaranteed time programme, as well as the DESTINYS (Disk Evolution Study Through Imaging of Nearby Young Stars) ESO Large Programme.
“The SPHERE view of the Chamaeleon I star-forming region: The full census of planet-forming disks with GTO and DESTINYS programs” (https://www.aanda.org/10.1051/0004-6361/202244005)
The team is composed of C. Ginski (University of Galway, Ireland; Leiden Observatory, Leiden University, the Netherlands [Leiden]; Anton Pannekoek Institute for Astronomy, University of Amsterdam, the Netherlands [API]), R. Tazaki (API), M. Benisty (Univ. Grenoble Alpes, CNRS, IPAG, France [Grenoble]), A. Garufi (INAF, Osservatorio Astrofisico di Arcetri, Italy), C. Dominik (API), Á. Ribas (European Southern Observatory, Chile [ESO Chile]), N. Engler (ETH Zurich, Institute for Particle Physics and Astrophysics, Switzerland), J. Hagelberg (Geneva Observatory, University of Geneva, Switzerland), R. G. van Holstein (ESO Chile), T. Muto (Division of Liberal Arts, Kogakuin University, Japan), P. Pinilla (Max-Planck-Institut für Astronomie, Germany [MPIA]; Mullard Space Science Laboratory, University College London, UK), K. Kanagawa (Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Japan), S. Kim (Department of Astronomy, Tsinghua University, China), N. Kurtovic (MPIA), M. Langlois (Centre de Recherche Astrophysique de Lyon, CNRS, UCBL, France), J. Milli (Grenoble), M. Momose (College of Science, Ibaraki University, Japan [Ibaraki]), R. Orihara (Ibaraki), N. Pawellek (Department of Astrophysics, University of Vienna, Austria), T. O. B. Schmidt (Hamburger Sternwarte, Germany), F. Snik (Leiden), and Z. Wahhaj (ESO Chile).
“The SPHERE view of the Taurus star-forming region: The full census of planet-forming disks with GTO and DESTINYS programs” (https://www.aanda.org/10.1051/0004-6361/202347586)
The team is composed of A. Garufi (INAF, Osservatorio Astrofisico di Arcetri, Italy [INAF Arcetri]), C. Ginski (University of Galway, Ireland), R. G. van Holstein (European Southern Observatory, Chile [ESO Chile]), M. Benisty (Laboratoire Lagrange, Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, France; Univ. Grenoble Alpes, CNRS, IPAG, France [Grenoble]), C. F. Manara (European Southern Observatory, Germany), S. Pérez (Millennium Nucleus on Young Exoplanets and their Moons [YEMS]; Departamento de Física, Universidad de Santiago de Chile, Chile [Santiago]), P. Pinilla (Mullard Space Science Laboratory, University College London, UK), A. Ribas (Institute of Astronomy, University of Cambridge, UK), P. Weber (YEMS, Santiago), J. Williams (Institute for Astronomy, University of Hawai‘i, USA), L. Cieza (Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Chile [Diego Portales]; YEMS), C. Dominik (Anton Pannekoek Institute for Astronomy, University of Amsterdam, the Netherlands [API]), S. Facchini (Dipartimento di Fisica, Università degli Studi di Milano, Italy), J. Huang (Department of Astronomy, Columbia University, USA), A. Zurlo (Diego Portales; YEMS), J. Bae (Department of Astronomy, University of Florida, USA), J. Hagelberg (Observatoire de Genève, Université de Genève, Switzerland), Th. Henning (Max Planck Institute for Astronomy, Germany [MPIA]), M. R. Hogerheijde (Leiden Observatory, Leiden University, the Netherlands; API), M. Janson (Department of Astronomy, Stockholm University, Sweden), F. Ménard (Grenoble), S. Messina (INAF - Osservatorio Astrofisico di Catania, Italy), M. R. Meyer (Department of Astronomy, The University of Michigan, USA), C. Pinte (School of Physics and Astronomy, Monash University, Australia; Grenoble), S. Quanz (ETH Zürich, Department of Physics, Switzerland [Zürich]), E. Rigliaco (Osservatorio Astronomico di Padova, Italy [Padova]), V. Roccatagliata (INAF Arcetri), H. M. Schmid (Zürich), J. Szulágyi (Zürich), R. van Boekel (MPIA), Z. Wahhaj (ESO Chile), J. Antichi (INAF Arcetri), A. Baruffolo (Padova), and T. Moulin (Grenoble).
“Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): The SPHERE view of the Orion star-forming region” (https://www.aanda.org/10.1051/0004-6361/202347452)
The team is composed of P.-G. Valegård (Anton Pannekoek Institute for Astronomy, University of Amsterdam, the Netherlands [API]), C. Ginski (University of Galway, Ireland), A. Derkink (API), A. Garufi (INAF, Osservatorio Astrofisico di Arcetri, Italy), C. Dominik (API), Á. Ribas (Institute of Astronomy, University of Cambridge, UK), J. P. Williams (Institute for Astronomy, University of Hawai‘i, USA), M. Benisty (University of Grenoble Alps, CNRS, IPAG, France), T. Birnstiel (University Observatory, Faculty of Physics, Ludwig-Maximilians-Universität München, Germany [LMU]; Exzellenzcluster ORIGINS, Germany), S. Facchini (Dipartimento di Fisica, Università degli Studi di Milano, Italy), G. Columba (Department of Physics and Astronomy "Galileo Galilei" - University of Padova, Italy; INAF – Osservatorio Astronomico di Padova, Italy), M. Hogerheijde (API; Leiden Observatory, Leiden University, the Netherlands [Leiden]), R. G. van Holstein (European Southern Observatory, Chile), J. Huang (Department of Astronomy, Columbia University, USA), M. Kenworthy (Leiden), C. F. Manara (European Southern Observatory, Germany), P. Pinilla (Mullard Space Science Laboratory, University College London, UK), Ch. Rab (LMU; Max-Planck-Institut für extraterrestrische Physik, Germany), R. Sulaiman (Department of Physics, American University of Beirut, Lebanon), A. Zurlo (Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Chile; Escuela de Ingeniería Industrial, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Chile; Millennium Nucleus on Young Exoplanets and their Moons).
The European Southern Observatory (ESO) enables scientists worldwide to discover the secrets of the Universe for the benefit of all. We design, build and operate world-class observatories on the ground — which astronomers use to tackle exciting questions and spread the fascination of astronomy — and promote international collaboration for astronomy. Established as an intergovernmental organisation in 1962, today ESO is supported by 16 Member States (Austria, Belgium, Czechia, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), along with the host state of Chile and with Australia as a Strategic Partner. ESO’s headquarters and its visitor centre and planetarium, the ESO Supernova, are located close to Munich in Germany, while the Chilean Atacama Desert, a marvellous place with unique conditions to observe the sky, hosts our telescopes. ESO operates three observing sites: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its Very Large Telescope Interferometer, as well as survey telescopes such as VISTA. Also at Paranal ESO will host and operate the Cherenkov Telescope Array South, the world’s largest and most sensitive gamma-ray observatory. Together with international partners, ESO operates ALMA on Chajnantor, a facility that observes the skies in the millimetre and submillimetre range. At Cerro Armazones, near Paranal, we are building “the world’s biggest eye on the sky” — ESO’s Extremely Large Telescope. From our offices in Santiago, Chile we support our operations in the country and engage with Chilean partners and society.
The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.
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JOURNAL
Astronomy and Astrophysics
Finding new physics in debris from colliding neutron stars
Neutron star mergers are a treasure trove for new physics signals, with implications for determining the true nature of dark matter, according to research from Washington University in St. Louis.
On Aug. 17, 2017, the Laser Interferometer Gravitational-wave Observatory (LIGO), in the United States, and Virgo, a detector in Italy, detected gravitational waves from the collision of two neutron stars. For the first time, this astronomical event was not only heard in gravitational waves but also seen in light by dozens of telescopes on the ground and in space.
Physicist Bhupal Dev in Arts & Sciences used observations from this neutron star merger — an event identified in astronomical circles as GW170817 — to derive new constraints on axion-like particles. These hypothetical particles have not been directly observed, but they appear in many extensions of the standard model of physics.
Axions and axion-like particles are leading candidates to compose part or all of the “missing” matter, or dark matter, of the universe that scientists have not been able to account for yet. At the very least, these feebly-interacting particles can serve as a kind of portal, connecting the visible sector that humans know much about to the unknown dark sector of the universe.
“We have good reason to suspect that new physics beyond the standard model might be lurking just around the corner,” said Dev, first author of the study in Physical Review Letters and a faculty fellow of the university’s McDonnell Center for the Space Sciences.
When two neutron stars merge, a hot, dense remnant is formed for a brief period of time. This remnant is an ideal breeding ground for exotic particle production, Dev said. “The remnant gets much hotter than the individual stars for about a second before settling down into a bigger neutron star or a black hole, depending on the initial masses,” he said.
These new particles quietly escape the debris of the collision and, far away from their source, can decay into known particles, typically photons. Dev and his team — including WashU alum Steven Harris (now NP3M fellow at Indiana University), as well as Jean-Francois Fortin, Kuver Sinha and Yongchao Zhang — showed that these escaped particles give rise to unique electromagnetic signals that can be detected by gamma-ray telescopes, such as NASA’s Fermi-LAT.
The research team analyzed spectral and temporal information from these electromagnetic signals and determined that they could distinguish the signals from the known astrophysical background. Then they used Fermi-LAT data on GW170817 to derive new constraints on the axion-photon coupling as a function of the axion mass. These astrophysical constraints are complementary to those coming from laboratory experiments, such as ADMX, which probe a different region of the axion parameter space.
In the future, scientists could use existing gamma-ray space telescopes, like the Fermi-LAT, or proposed gamma-ray missions, like the WashU-led Advanced Particle-astrophysics Telescope (APT), to take other measurements during neutron star collisions and help improve upon their understanding of axion-like particles.
“Extreme astrophysical environments, like neutron star mergers, provide a new window of opportunity in our quest for dark sector particles like axions, which might hold the key to understanding the missing 85% of all the matter in the universe,” Dev said.
This work was supported by the Department of Energy’s Office of Science.
JOURNAL
Physical Review Letters
ARTICLE TITLE
First Constraints on the Photon Coupling of Axionlike Particles from Multimessenger Studies of the Neutron Star Merger GW170817
ARTICLE PUBLICATION DATE
5-Mar-2024
Juno spacecraft measures oxygen production on Jupiter’s moon, Europa
Study co-authored by SwRI scientists puts narrow constraints on how much oxygen is produced within Europa’s ice shell.
IMAGE:
FOR THE FIRST TIME, SWRI SCIENTISTS USED THE JOVIAN AURORAL DISTRIBUTIONS EXPERIMENT (JADE) INSTRUMENT TO DEFINITIVELY DETECT OXYGEN AND HYDROGEN IN THE ATMOSPHERE OF ONE OF JUPITER’S LARGEST MOONS, EUROPA. NASA’S JUNO SPACECRAFT, USING ITS SWRI-DEVELOPED INSTRUMENT, MADE THE MEASUREMENTS DURING A 2022 FLYBY OF EUROPA.
view moreCREDIT: NASA/JPL-CALTECH
SAN ANTONIO — March 5, 2024—NASA’s Juno spacecraft has directly measured charged oxygen and hydrogen molecules from the atmosphere of one of Jupiter’s largest moons, Europa. According to a new study co-authored by SwRI scientists and led by Princeton University, these observations provide key constraints on the potential oxygenation of its subsurface ocean.
“These findings have direct implications on the potential habitability of Europa,” said Juno Principal Investigator Dr. Scott Bolton of SwRI, a co-author of the study. “This study provides the first direct in-situ measurement of water components existing in Europa’s atmosphere, giving us a narrow range that could support habitability.”
In 2022, Juno completed a flyby of Europa, coming as close as 352 kilometers to the moon. The SwRI-developed Jovian Auroral Distributions Experiment (JADE) instrument aboard Juno detected significant amounts of charged molecular oxygen and hydrogen lost from the atmosphere.
“For the first time, we’ve been able to definitively detect hydrogen and oxygen with in-situ measurements and further confirm that Europa’s atmosphere is made primarily of hydrogen and oxygen molecules,” said SwRI Staff Scientist and co-author Dr. Robert Ebert.
The source of these molecules is thought to be water ice on Europa’s surface. Jupiter’s rampant radiation breaks H2O’s molecular bonds, leaving behind oxygen and hydrogen. The heavier oxygen molecules remain more constrained to the surface, or near-surface atmosphere, while the lighter-weight hydrogen predominately escapes into the atmosphere and beyond. Oxygen produced in the ice is either lost from the atmosphere and/or sequestered in the surface. Oxygen retained in Europa’s ice may work its way to its subsurface ocean as a possible source of metabolic energy.
“Europa’s ice shell absorbs radiation, protecting the ocean underneath. This absorption also produces oxygen within the ice, so in a way, the ice shell acts as Europa’s lung, providing a potential oxygen source for the ocean.” said Princeton University Research Scholar Dr. Jamey Szalay, the study’s lead author. “We put narrow constraints on the total oxygen production at Europa currently at around 12 kg per second. Before Juno, previous estimates ranged from a few kg per second to over 1,000 kg per second. The findings unambiguously demonstrate oxygen is continuously produced in the surface, just a good bit lower than we expected.”
“We designed JADE to measure the charged particles that create Jupiter’s auroras,” said SwRI Staff Scientist and co-author Dr. Frederic Allegrini. “Flybys of Europa were not part of the primary Juno mission. JADE was designed to work in a high-radiation environment but not necessarily Europa’s environment, which is constantly bombarded with high levels of radiation. Nonetheless, the instrument performed beautifully.”
The new measurements contribute to a greater understanding of Europa and its environment, open the door for newer, more precise models. The study’s new estimation of how much oxygen is produced within Europa’s surface, for instance, could inform future research related to its subsurface ocean and potential habitability. As these observations provide the first charged particle composition measurements within Europa’s vicinity, they provide an important new window into the moons’ complex interaction with its environment.
“Europa is a fascinating object because scientists are confident a liquid ocean exists in its interior,” Ebert said. “Water is important for the existence of life and can be found in or on objects with varying characteristics. Europa is a good place to search for water within our solar system.”
The paper “Oxygen production from dissociation of Europa’s water ice surface,” appears in Nature Astronomy: https://www.nature.com/articles/s41550-024-02206-x.
For more information, visit https://www.swri.org/planetary-science.
For the first time, SwRI scientists used the Jovian Auroral Distributions Experiment (JADE) instrument to definitively detect oxygen and hydrogen in the atmosphere of one of Jupiter’s largest moons, Europa. NASA’s Juno spacecraft, using its SwRI-developed instrument, made the measurements during a 2022 flyby of Europa.
CREDIT
NASA/JPL/University of Arizona
JOURNAL
Nature Astronomy
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Oxygen production from dissociation of Europa's water-ice surface
ARTICLE PUBLICATION DATE
4-Mar-2024
Study determines the original orientations of rocks drilled on Mars
The “oriented” samples, the first of their kind from any planet, could shed light on Mars’ ancient magnetic field.
IMAGE:
MIT GEOLOGISTS DETERMINED THE ORIGINAL ORIENTATION OF MANY OF THE BEDROCK SAMPLES COLLECTED ON MARS BY THE PERSEVERANCE ROVER, DEPICTED IN THIS IMAGE RENDERING. THE FINDINGS CAN GIVE SCIENTISTS CLUES TO THE CONDITIONS IN WHICH THE ROCKS ORIGINALLY FORMED.
view moreCREDIT: IMAGE: NASA/JPL-CALTECH
As it trundles around an ancient lakebed on Mars, NASA’s Perseverance rover is assembling a one-of-a-kind rock collection. The car-sized explorer is methodically drilling into the Red Planet’s surface and pulling out cores of bedrock that it’s storing in sturdy titanium tubes. Scientists hope to one day return the tubes to Earth and analyze their contents for traces of embedded microbial life.
Since it touched down on the surface of Mars in 2021, the rover has filled 20 of its 43 tubes with cores of bedrock. Now, MIT geologists have remotely determined a crucial property of the rocks collected to date, which will help scientists answer key questions about the planet’s past.
In a study appearing today in the journal Earth and Space Science, an MIT team reports that they have determined the original orientation of most bedrock samples collected by the rover to date. By using the rover’s own engineering data, such as the positioning of the vehicle and its drill, the scientists could estimate the orientation of each sample of bedrock before it was drilled out from the Martian ground.
The results represent the first time scientists have oriented samples of bedrock on another planet. The team’s method can be applied to future samples that the rover collects as it expands its exploration outside the ancient basin. Piecing together the orientations of multiple rocks at various locations can then give scientists clues to the conditions on Mars in which the rocks originally formed.
“There are so many science questions that rely on being able to know the orientation of the samples we’re bringing back from Mars,” says study author Elias Mansbach, a graduate student in MIT’s Department of Earth, Atmospheric and Planetary Sciences.
“The orientation of rocks can tell you something about any magnetic field that may have existed on the planet,” adds Benjamin Weiss, professor of planetary sciences at MIT. “You can also study how water and lava flowed on the planet, the direction of the ancient wind, and tectonic processes, like what was uplifted and what sunk. So it’s a dream to be able to orient bedrock on another planet, because it’s going to open up so many scientific investigations.”
Weiss and Mansbach’s co-authors are Tanja Bosak and Jennifer Fentress at MIT, along with collaborators at multiple institutions including the Jet Propulsion Laboratory at Caltech.
Profound shift
The Perseverance rover, nicknamed “Percy,” is exploring the floor of Jezero Crater, a large impact crater layered with igneous rocks, which may have been deposited from past volcanic eruptions, as well as sedimentary rocks that likely formed from long-dried-out rivers that fed into the basin.
“Mars was once warm and wet, and there’s a possibility there was life there at one time,” Weiss says. “It’s now cold and dry, and something profound must have happened on the planet.”
Many scientists, including Weiss, suspect that Mars, like Earth, once harbored a magnetic field that shielded the planet from the sun’s solar wind. Conditions then may have been favorable for water and life, at least for a time.
“Once that magnetic field went away, the sun’s solar wind — this plasma that boils off the sun and moves faster than the speed of sound — just slammed into Mars’ atmosphere and may have removed it over billions of years,” Weiss says. “We want to know what happened, and why.”
The rocks beneath the Martian surface likely hold a record of the planet’s ancient magnetic field. When rocks first form on a planet’s surface, the direction of their magnetic minerals is set by the surrounding magnetic field. The orientation of rocks can thus help to retrace the direction and intensity of the planet’s magnetic field and how it changed over time.
Since the Perseverance rover was collecting samples of bedrock, along with surface soil and air, as part of its exploratory mission, Weiss, who is a member of the rover’s science team, and Mansbach looked for ways to determine the original orientation of the rover’s bedrock samples as a first step toward reconstructing Mars’ magnetic history.
“It was an amazing opportunity, but initially there was no mission requirement to orient bedrock,” Mansbach notes.
Roll with it
Over several months, Mansbach and Weiss met with NASA engineers to hash out a plan for how to estimate the original orientation of each sample of bedrock before it was drilled out of the ground. The problem was a bit like predicting what direction a small circle of sheetcake is pointing, before twisting a round cookie cutter in to pull out a piece. Similarly, to sample bedrock, Perseverance corkscrews a tube-shaped drill into the ground at a perpendicular angle, then pulls the drill directly back out, along with any rock that it penetrates.
To estimate the orientation of the rock before it was drilled out of the ground, the team realized they need to measure three angles, the hade, azimuth, and roll, which are similar to the pitch, yaw, and roll of a boat. The hade is essentially the tilt of the sample, while the azimuth is the absolute direction the sample is pointing relative to true north. The roll refers to how much a sample must turn before returning to its original position.
In talking with engineers at NASA, the MIT geologists found that the three angles they required were related to measurements that the rover takes on its own in the course of its normal operations. They realized that to estimate a sample’s hade and azimuth they could use the rover’s measurements of the drill’s orientation, as they could assume the tilt of the drill is parallel to any sample that it extracts.
To estimate a sample’s roll, the team took advantage of one of the rover’s onboard cameras, which snaps an image of the surface where the drill is about to sample. They reasoned that they could use any distinguishing features on the surface image to determine how much the sample would have to turn in order to return to its original orientation.
In cases where the surface bore no distinguishing features, the team used the rover’s onboard laser to make a mark in the rock, in the shape of the letter “L,” before drilling out a sample — a move that was jokingly referred to at the time as the first graffiti on another planet.
By combining all the rover’s positioning, orienting, and imaging data, the team estimated the original orientations of all 20 of the Martian bedrock samples collected so far, with a precision that is comparable to orienting rocks on Earth.
“We know the orientations to within 2.7 degrees uncertainty, which is better than what we can do with rocks in the Earth,” Mansbach says. “We’re working with engineers now to automate this orienting process so that it can be done with other samples in the future.”
“The next phase will be the most exciting,” Weiss says. “The rover will drive outside the crater to get the oldest known rocks on Mars, and it’s an incredible opportunity to be able to orient these rocks, and hopefully uncover a lot of these ancient processes.”
This research was supported, in part, by NASA and the Mars 2020 Participating Scientist program.
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Written by Jennifer Chu, MIT News
Paper: “Oriented Bedrock Samples Drilled by the Perseverance Rover on Mars”
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023EA003322
JOURNAL
Earth and Space Science
ARTICLE TITLE
“Oriented Bedrock Samples Drilled by the Perseverance Rover on Mars”
Scientist proposed a research on space noncooperative target trajectory tracking based on maneuvering parameter estimation
IMAGE:
BLOCK DIAGRAM OF TRAJECTORY TRACKING ALGORITHM.
view moreCREDIT: SPACE: SCIENCE & TECHNOLOGY
Firstly, the authors briefly describe two models for tracking the maneuvering trajectories of non-cooperative space targets: the relative dynamics model and the indirect measurement model. In the relative dynamics model, tracking the maneuvering trajectory of the target is modeled as a problem of tracking the target's position over short discrete time intervals. On the other hand, the indirect measurement model transforms radar-derived values directly into measurements in the Local Vertical Local Horizontal (LVLH) coordinate system.
Next, the authors address the tracking problem of targets with complex maneuvering models and high frequency observation, proposing a real-time maneuver trajectory tracking method based on the rapid estimation of non-cooperative target parameter estimation. The block diagram of trajectory tracking algorithm. is illustrated in Figure 2. By selecting discrete nodes tk − 2, tk − 1, and tk at high-frequency observations, the relative position and velocity of the non-cooperative target are obtained in real-time. At each node, utilizing historical observation data and maneuver parameter estimates, the algorithm predicts the target's relative position pk at the next node tk. The assumption is made that the maneuver parameters remain unchanged within the discretization period, allowing for complete relative state information at tk − 1. The discrete trajectory tracking algorithm predicts the target's position to track the maneuvering trajectory. This process is repeated at different nodes, achieving effective tracking of the continuous maneuvering trajectory based on measurement data. However, historical measurement errors can affect the identification of the target's acceleration. To mitigate the impact of measurement errors on target acceleration identification, a mean filtering method is applied to smooth the historical measurements over the period from tk − 2 to tk − 1. Considering that non-cooperative target maneuver parameters satisfy three-axis acceleration constraints, an estimation of maneuver parameters is generated using a shooting method to ensure a uniform distribution within the constraint range. The target's relative state at time tk − 1 is obtained through numerical integration. The differential algebra method is employed to solve the computational burden of the Monte Carlo method, ensuring the efficiency of the real-time tracking process. The process of the maneuvering parameter fast identification algorithm is illustrated in Figure 3. This method initially selects the nominal state X1k−2 and defines the associated state deviation as △x, where each state can be described by adding deviation values to the nominal state. Then, a Taylor expansion is performed near the nominal state X1k−2. Utilizing the Runge-Kutta integrator, the state at time tk − 2 is mapped to tk − 1, resulting in a semi-analytical polynomial solution [Xik−1]. By comparing the error of the estimated value and the measured value, the best estimate state Xk−1 is obtained. Finally, the optimal estimate value ak−2 for the target's maneuver parameters from tk − 2 to tk − 1 is obtained through Xk−1[key]. The entire process is implemented through the Jet Transport algorithm for polynomial form numerical calculations, ensuring a reduced computational burden during real-time tracking.
Furthermore, the process of the discrete trajectory tracking algorithm for the space noncooperative target is shown in Fig.4. Considering that the trajectory discretization period interval of the noncooperative target is short, it is assumed that the maneuvering parameters of the target in 2 consecutive periods are equal. Therefore, by solving equations, the relative state xk − 1 of the target is obtained. Using the state transition matrix F and parameters θ, the target's relative state xk at time tk is calculated, achieving the trajectory tracking of the target.
Next, to evaluate the algorithm's performance, the authors conducted simulations for non-cooperative target tracking and analyzed the tracking errors and time costs of the proposed method compared to the interactive multimodel method (IMM). Simulation conditions included the orbital parameters and initial relative states of the non-cooperative target, with a discrete trajectory tracking period of 0.5 seconds using an onboard radar sensor measurement model. Gaussian white noise with zero mean was set as the measurement noise, and 2000 acceleration shots were considered. The IMM algorithm was applied with two models, and 200 sets of repeated experiments were conducted under the same conditions.
The maneuvering trajectory of the non-cooperative target was divided into three stages and simulated in the LVLH coordinate system, including the real trajectory and measured trajectory. The results indicate that the proposed algorithm exhibits a significant advantage over the IMM algorithm in terms of trajectory tracking accuracy. The Root Mean Square Error (RMSE) of position estimates shows that the performance of the proposed algorithm is significantly better than the IMM algorithm in all three directions. The average RMSE of position estimates for the three axes increased by 94.37%, 93.53%, and 93.75%, respectively, as shown in Table 2. Additionally, Fig.7 demonstrates the superior performance of the proposed algorithm in terms of acceleration estimation. Furthermore, the authors conducted a detailed analysis of simulation results, including the average RMSE of position estimates, the performance of target acceleration estimation, and the algorithm's runtime. The experiments indicate that the proposed method not only excels in tracking performance but also satisfies the constraints of real-time maneuver trajectory tracking, despite the higher computational cost compared to the IMM algorithm. In summary, for non-cooperative targets with high maneuvering frequencies, the proposed algorithm demonstrates better performance in maneuver tracking problems.
In conclusion, the authors summarized their work and highlighted two innovative aspects of the study: (a) They proposed a rapid target maneuver acceleration estimation method based on the differential algebra approach, avoiding the delayed response of traditional filtering algorithms to large maneuvering target trajectories. Compared to the IMM method, the proposed algorithm provides a more accurate estimation of the target's maneuver acceleration, closely resembling the actual maneuvering process of the target. (b). The method achieves target tracking through trajectory discretization, rapid maneuver parameter estimation, and trajectory prediction. In comparison to IMM, the proposed algorithm is more accurate, with a trajectory tracking accuracy improvement of approximately 93.07%.
JOURNAL
Space Science & Technology
ARTICLE TITLE
Space Noncooperative Target Trajectory Tracking Based on Maneuvering Parameter Estimation
The process of the maneuvering parameter fast identification algorithm.
The process of the trajectory tracking algorithm
The estimated and true target acceleration.
The mean root error of the position estimation
CREDIT
Space: Science & Technology
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