SPACE
Mystery of ‘slow’ solar wind unveiled by Solar Orbiter mission
Scientists have come a step closer to identifying the mysterious origins of the ‘slow’ solar wind, using data collected during the Solar Orbiter spacecraft’s first close journey to the Sun
IMAGE:
DR STEPH YARDLEY OF NORTHUMBRIA UNIVERSITY
view moreCREDIT: SIMON VEIT-WILSON/NORTHUMBRIA UNIVERSITY
Scientists have come a step closer to identifying the mysterious origins of the ‘slow’ solar wind, using data collected during the Solar Orbiter spacecraft’s first close journey to the Sun.
Solar wind, which can travel at hundreds of kilometres per second, has fascinated scientists for years, and new research published in Nature Astronomy, is finally shedding light on how it forms.
Solar wind describes the continuous outflow of charged plasma particles from the Sun into space – with wind travelling at over 500km per second known as ‘fast’ and under 500km per second described as ‘slow’.
When this wind hits the Earth’s atmosphere it can result in the stunning aurora we know as the Northern Lights. But when larger quantities of plasma are released, in the form of a coronal mass ejection, it can also be hazardous, causing significant damage to satellites and communications systems.
Despite decades of observations, the sources and mechanisms that release, accelerate and transport solar wind plasma away from the Sun and into our solar system are not well understood – particularly the slow solar wind.
In 2020 the European Space Agency (ESA), with support from NASA, launched the Solar Orbiter mission. As well as capturing the closest and most detailed images of the Sun ever taken, one of the mission’s main aims is to measure and link the solar wind back to its area of origin on the Sun’s surface.
Described as ‘the most complex scientific laboratory ever to have been sent to the Sun’, there are ten different scientific instruments onboard Solar Orbiter – some in situ to collect and analyse samples of the solar wind as it passes the spacecraft, and other remote sensing instruments designed to capture high quality images of activity at the Sun’s surface.
By combining photographic and instrumental data, scientists have for the first time been able to identify more clearly where the slow solar wind originates. This has helped them to establish how it is able to leave the Sun and begin its journey into the heliosphere – the giant bubble around the Sun and its planets which protect our solar system from interstellar radiation.
Dr Steph Yardley of Northumbria University, Newcastle upon Tyne, led the research and explains: “The variability of solar wind streams measured in situ at a spacecraft close to the Sun provide us with a lot of information on their sources, and although past studies have traced the origins of the solar wind, this was done much closer to Earth, by which time this variability is lost.
“Because Solar Orbiter travels so close to the Sun, we can capture the complex nature of the solar wind to get a much clearer picture of its origins and how this complexity is driven by the changes in different source regions.”
The difference between the speed of the fast and slow solar wind is thought to be due to the different areas of the Sun’s corona, the outermost layer of its atmosphere, that they originate from.
The open corona refers to regions where magnetic field lines anchor to the Sun at only one end, and stretch out into space on the other, creating a highway for solar material to escape into space. These areas are cooler and are believed to be the source of the fast solar wind.
Meanwhile the closed corona refers to regions of the Sun where its magnetic field lines are closed — meaning they are connected to the solar surface at both ends. These can be seen as large bright loops that form over magnetically active regions.
Occasionally these closed magnetic loops will break, providing a brief opportunity for solar material to escape, in the same way it does through open magnetic field lines, before reconnecting and forming a closed loop once again. This generally takes place in areas where the open and closed corona meet.
One of the aims of Solar Orbiter is to test a theory that the slow solar wind originates from the closed corona and is able to escape into space through this process of magnetic field lines breaking and reconnecting.
One way the scientific team were able to test this theory was by measuring the ‘composition’ or make up of solar wind streams.
The combination of heavy ions contained in solar material differs depending on where it has originated from; the hotter, closed versus the cooler, open corona.
Using the instruments onboard Solar Orbiter, the team were able to analyse the activity taking place on the surface of the Sun and then match this with the solar wind streams collected by the spacecraft.
Using the images of the Sun’s surface captured by Solar Orbiter they were able to pinpoint that the slow wind streams had come from an area where the open and closed corona met, proving the theory that the slow wind is able to escape from closed magnetic field lines through the process of breaking and reconnection.
As Dr Yardley, of Northumbria University’s Solar and Space Physics research group, explains: “The varying composition of the solar wind measured at Solar Orbiter was consistent with the change in composition across the sources in the corona.
“The changes in composition of the heavy ions along with the electrons provide strong evidence that not only is the variability driven by the different source regions, but it is also due to reconnection processes occurring between the closed and open loops in the corona.”
The ESA Solar Orbiter mission is an international collaboration, with scientists and institutions from around the world working together, contributing specialist skills and equipment.
Daniel Müller, ESA Project Scientist for Solar Orbiter, said: “From the beginning, a central goal of the Solar Orbiter mission has been to link dynamic events on the Sun to their impact on the surrounding plasma bubble of the heliosphere.
“To achieve this, we need to combine remote observations of the Sun with in-situ measurements of the solar wind as it flows past the spacecraft. I am immensely proud of the entire team for making these complex measurements successfully.
“This result confirms that Solar Orbiter is able to make robust connections between the solar wind and its source regions on the solar surface. This was a key objective of the mission and opens the way for us to study the solar wind’s origin in unprecedented detail.”
Among the instruments onboard Solar Orbiter is the Heavy Ion Sensor (HIS), developed in part by researchers and engineers from the University of Michigan's Space Physics Research Laboratory in the department of Climate and Space Sciences and Engineering. The sensor was designed to measure heavy ions in the solar wind, which can be used to determine where the solar wind came from.
“Each region of the Sun can have a unique combination of heavy ions, which determines the chemical composition of a stream of solar wind. Because the chemical composition of the solar wind remains constant as it travels out into the solar system, we can use these ions as a fingerprint to determine the origin of a specific stream of the solar wind in the lower part of the Sun's atmosphere,” said Susan Lepri, a professor of climate and spaces sciences and engineering at the University of Michigan and the deputy principal investigator of the Heavy Ion Sensor.
The electrons in the solar wind are measured by an Electron Analyser System (EAS), developed by UCL’s Mullard Space Science Laboratory, where Dr Yardley is an Honorary Fellow.
Professor Christopher Owen, of UCL, said: “The instrument teams spent more than a decade designing, building and preparing their sensors for launch, as well as planning how best to operate them in a coordinated way. So it is highly gratifying to now see the data being put together to reveal which regions of the Sun are driving the slow solar wind and its variability.”
The Proton-Alpha Sensor (PAS), which measures wind speed, has been designed and developed by Paul Sabatier University’s Institut de Recherche en Astrophysique et Planétologie in Toulouse, France.
Together, these instruments make up the Solar Wind Analyser senor suite on board Solar Orbiter, for which UCL’s Professor Christopher Owen is principal investigator.
Speaking about future research plans, Dr Yardley said: “So far, we have only analysed Solar Orbiter data in this way for this particular interval. It will be very interesting to look at other cases using Solar Orbiter and to also make a comparison to datasets from other close-in missions such as NASA’s Parker Solar Probe.”
The paper, Multi-source connectivity as the driver of solar wind variability in the heliosphere, is due to be published in Nature Astronomy on Tuesday 28 May 2024.
ESA Solar Orbiter instruments
ESA Solar Orbiter
ESA Solar Orbiter
CREDIT
European Space Agency (ESA)
European Space Agency (ESA)
Coronal hole in the Sun [VIDEO] |
JOURNAL
Nature Astronomy
METHOD OF RESEARCH
Data/statistical analysis
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Multi-source connectivity as the driver of solar wind variability in the heliosphere
ARTICLE PUBLICATION DATE
28-May-2024
Euclid space mission releases first scientific results and new images of the cosmos
The release marks the start of Euclid’s main survey, says physicist at Maynooth University, the only Irish university in the Euclid consortium. We are on the threshold of a new era in cosmology,” says MU’s Prof Peter Coles
MAYNOOTH UNIVERSITY
IMAGE:
EUCLID CAPTURES NGC 6744, ONE OF THE LARGEST SPIRAL GALAXIES BEYOND OUR LOCAL PATCH OF SPACE, LYING 30 MILLION LIGHT-YEARS AWAY
view moreCREDIT: ESA/EUCLID/EUCLID CONSORTIUM/NASA
European space mission Euclid has released early scientific papers based on observations made by the space telescope, along with five new astronomical images of the Universe, as the project sets about unravelling the secrets of the cosmos.
The new images are part of Euclid’s Early Release Observations (EROs) and accompany the mission’s first scientific data and 10 forthcoming science papers. Their publication comes less than a year after the space telescope’s launch and some six months after it returned its first full-colour images of the cosmos.
The scientific papers are based on observations and analysis of 17 targets and contain exciting scientific results including:
- the discovery of free-floating new-born planets
- newly identified extragalactic star clusters
- new low-mass dwarf galaxies in a nearby cluster of galaxies
- the discovery of very distant bright galaxies
The five new ERO images follow the release of an initial five images last November. The images obtained by Euclid are at least four times sharper than those that can be taken from ground-based telescopes. They cover large patches of sky at unrivalled depth, looking far into the distant Universe using both visible and infrared light.
The latest Euclid images include observations of:
- Messier 78, a reflection nebula
- Abell 2390 and Abell 2764, two giant clusters of galaxies
- NGC 6744, a spiral galaxy very similar to the Milky Way
- the Dorado Group, a loose agglomeration of galaxies
Speaking about the data release, Prof Peter Coles of Maynooth University’s Department of Theoretical Physics, the only Irish-based academic involved in the Euclid consortium, said: “Today's release of new data and technical papers from Euclid is exciting in itself but also marks the start, after months of painstaking calibration and testing of the instruments, of Euclid's main cosmological survey. We are on the threshold of a new era in cosmology.”
“Maynooth is the only University in Ireland to be involved in this mission and it is very exciting to be at the forefront of such an important scientific development.”
Launched from Cape Canaveral on July 1, 2023, Euclid’s mission is to map the distribution of distant galaxies across more than one-third of the sky to extract information about the constituents of the universe, and test whether current ideas about cosmic evolution are correct.
“Euclid is a unique, ground-breaking mission, and these are the first datasets to be made public – it’s an important milestone,” says Valeria Pettorino, ESA’s Euclid Project Scientist. “The images and associated science findings are impressively diverse in terms of the objects and distances observed. They include a variety of science applications, and yet represent a mere 24 hours of observations. They give just a hint of what Euclid can do. We are looking forward to six more years of data to come!”
The next thing to look forward to from Euclid is a taster for the main Euclid survey around March 2025. The first year of survey data (DR1) will be released in June 2026 while the full survey will be completed in 2031.
A close-up of Messier 78, this image illustrates how newly forming stars create a 'cavity' in the surrounding molecular cloud by generating winds of charged particles
CREDIT
ESA/Euclid/Euclid Consortium/NASA
Scientists discover CO2 and CO ices in outskirts of solar system
A UCF-led research team’s findings revealed a vast presence of ancient carbon dioxide and carbon monoxide ices on trans-Neptunian objects, suggesting carbon dioxide may have existed at the formation of our solar system.
ORLANDO, May 24, 2024 – For the first time, carbon dioxide and carbon monoxide ices have been observed in the far reaches of our solar system on trans-Neptunian objects (TNOs).
A research team, led by planetary scientists Mário Nascimento De Prá and Noemí Pinilla-Alonso from the University of Central Florida’s Florida Space Institute (FSI), made the findings by using the infrared spectral capabilities of the James Webb Space Telescope (JWST) to analyze the chemical composition of 59 trans-Neptunian objects and Centaurs.
The pioneering study, published this week in Nature Astronomy, suggests that carbon dioxide ice was abundant in the cold outer regions of the protoplanetary disk, the vast rotating disk of gas and dust from which the solar system formed. Further investigation is needed to understand the carbon monoxide ice’s origins, as it also prevalent on the TNOs in the study.
The researchers reported the detection of carbon dioxide in 56 TNOs and carbon monoxide in 28 (plus six with dubious or marginal detections), out of a sample of 59 objects observed with the JWST. Carbon dioxide was widespread on the surfaces of the trans-Neptunian population, independent of the dynamical class and body size while carbon monoxide was detected only in objects with a high carbon dioxide abundance, according to the study.
The work is part of the UCF-led Discovering the Surface Compositions of Trans-Neptunian Objects program (DiSCo-TNOs), one of the JWST programs focused on analyzing our solar system.
“It is the first time we observed this region of the spectrum for a large collection of TNOs, so in a sense, everything we saw was exciting and unique,” says de Prá, who co-authored the study. “We did not expect to find that carbon dioxide was so ubiquitous in the TNO region, and even less that carbon monoxide was present in so many TNOs.”
The discovery of the ices can further help us understand the formation of our solar system and how celestial objects may have migrated, he says.
“Trans-Neptunian Objects are relics from the process of planetary formation,” de Prá says. “These findings can impose important constraints about where these objects were formed, how they reached the region they inhabit nowadays, and how their surfaces evolved since their formation. Because they formed at greater distances to the Sun and are smaller than the planets, they contain the pristine information about the original composition of the protoplanetary disk.”
Chronicling Ancient Ice
Carbon monoxide ice was observed on Pluto by the New Horizons probe, but not until JWST was there an observatory powerful enough to pinpoint and detect traces of carbon monoxide ice or carbon dioxide ice on the largest population of TNOs.
Carbon dioxide is commonly found in many objects in our solar system. So, the DiSCo team was curious to see if it existed in greater quantities beyond the reaches of Neptune.
Possible reasons for the lack of previous detections of carbon dioxide ice on TNOs include a lower abundance, non-volatile carbon dioxide becoming buried under layers of other less volatile ices and refractory material over time, conversion into other molecules through irradiation, and simple observational limitations, according to the study.
The discovery of carbon dioxide and carbon monoxide on the TNOs provides some context while also raising many questions, de Prá says.
“While the carbon dioxide was probably accreted from the protoplanetary disk, the origin of the carbon monoxide is more uncertain,” he says. “The latter is a volatile ice even in the cold surfaces of the TNOs. We can’t rule out the carbon monoxide was primordially accreted and somehow was retained until present date. However, the data suggests that it could be produced by the irradiation from carbon-bearing ices.”
An Avalanche of Answers
Confirming the presence of carbon dioxide and carbon monoxide on TNOs opens many opportunities to further study and quantify how or why it is present, says Pinilla-Alonso, who also co-authored the study and leads the DiSCo-TNOs program.
“The discovery of carbon dioxide on trans-Neptunian objects was thrilling, but even more fascinating were its characteristics,” she says. “The spectral imprint of carbon dioxide revealed two distinct surface compositions within our sample. In some TNOs, carbon dioxide is mixed with other materials like methanol, water ice, and silicates. However, in another group — where carbon dioxide and carbon monoxide are major surface components — the spectral signature was strikingly unique. This stark carbon dioxide imprint is unlike anything observed on other solar system bodies or even replicated in laboratory settings.”
It now seems clear that when carbon dioxide is abundant, it appears isolated from other materials, but this alone doesn't explain the band shape, Pinilla-Alonso says. Understanding these carbon dioxide bands is another mystery, likely tied to their unique optical properties and how they reflect or absorb specific colors of light, she says.
It was commonly theorized that perhaps carbon dioxide may be present in TNOs as carbon dioxide exists in a gaseous state in comets, which are comparable in composition, Pinilla-Alonso says.
“In comets, we observe carbon dioxide as a gas, released from the sublimation of ices on or just below the surface,” she says. “However, since carbon dioxide had never been observed on the surface of TNOs, the common belief was that it was trapped beneath the surface. Our latest findings upend this notion. We now know that carbon dioxide is not only present on the surface of TNOs but is also more common than water ice, which we previously thought was the most abundant surface material. This revelation dramatically changes our understanding of the composition of TNOs and suggests that the processes affecting their surfaces are more complex than we realized.”
Thawing the Data
Study co-authors Elsa Hénault, a doctoral student at the Université Paris-Saclay’s Institut d'Astrophysique Spatiale, and French National Center of Scientific Research, and Rosario Brunetto, Hénault’s supervisor, brought a laboratory and chemical perspective into the interpretation of JWST observations.
Hénault analyzed and compared the absorption bands of carbon dioxide and carbon monoxide across all objects. While there was ample evidence of the ice, there was a great diversity in abundance and distribution, Hénault says.
“While we found CO2 to be ubiquitous across TNOs, it is definitely not uniformly distributed,” she says. “Some objects are poor in carbon dioxide while others are very rich in carbon dioxide and show carbon monoxide. Some objects display pure carbon dioxide while others have it mixed with other compounds. Linking the characteristics of carbon dioxide to orbital and physical parameters allowed us to conclude that carbon dioxide variations are likely representative of the objects’ different formation regions and early evolution.”
Through analysis, it is very likely that carbon dioxide was present in the protoplanetary disk, however, carbon monoxide is unlikely to be primordial, Hénault says.
“Carbon monoxide could be efficiently formed by the constant ion bombardment coming from our sun or other sources,” she says. “We are currently exploring this hypothesis by comparing the observations with ion irradiation experiments that can reproduce the freezing and ionizing conditions of TNO surfaces.”
The research brought some definite answers to longstanding questions dating back to the discovery of TNOs nearly 30 years ago, but researchers still have a long way to go, Hénault says.
“Other questions are now raised,” she says. “Notably, considering the origin and evolution of the carbon monoxide. The observations across the complete spectral range are so rich that they will definitely keep scientists busy for years to come.”
Although the DiSCo program observations are nearing a conclusion, the analysis and discussion of the results still have a long way to go. The foundational knowledge gained from the study will prove to be an important supplement for future planetary science and astronomy research, de Prá says.
“We have only scratched the surface of what these objects are made of and how they came to be,” he says. “We now need to understand the relationship between these ices with the other compounds present in their surfaces and understand the interplay between their formation scenario, dynamical evolution, volatile retention and irradiation mechanisms throughout the history of the solar system.”
Team Effort
Study co-authors also included Ana Carolina de Souza Feliciano, Charles Schambeau, Yvonne Pendelton, Dale Cruikshank and Brittany Harvison with UCF; Bryan Holler and John Stansberry with the Space Telescope Science Institute; Jorge Carvano with the Observatorio Nacional do Rio de Janeiro in Brazil; Javier Licandro and Vania Lorenzi with the Instituto de Astrofísica de Canarias in Spain; Thomas Müller with the Max-Planck-Institut für extraterrestrische Physik in Germany; Nuno Peixinho with the Instituto de Astrofísica e Ciencias do Espaço in Portugal; Aurélie Guilbert-Lepoutre with the Laboratoire de Géologie de Lyon in France; Michele Bannister with the University of Canterbury in New Zealand; and Joshua Emery and Lucas McClure with Northern Arizona University.
Researchers’ Credentials:
De Prá joined UCF FSI in 2022 as an assistant scientist. He previously spent nearly four years as a preeminent post-doctoral associate at FSI. De Prá received his doctorate in astronomy in 2017 at the Observatório Nacional do Rio de Janeiro, Brazil. He works with observational planetary sciences using several ground and space-based telescopes to study the connection between different small body populations.
Pinilla-Alonso is a professor at FSI and joined 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.
JOURNAL
Nature Astronomy
METHOD OF RESEARCH
Imaging analysis
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Widespread CO2 and CO ices in the trans-Neptunian population revealed by JWST/DiSCo-TNOs
ARTICLE PUBLICATION DATE
22-May-2024
Researchers introduce a Planetary Inclusion Scale
UNIVERSITY OF EASTERN FINLAND
Social inclusion and having a sense of belonging with other people are key elements of a good life. However, the fate of humanity is a challenge that extends beyond our social reality. Experiences of belonging and inclusion, understood in a broader sense than before, may be crucial for a sustainable future.
In an article published in International Journal of Social Pedagogy, a team of researchers propose a new Planetary Inclusion Scale that structures our planetary relationship three-dimensionally based on temporal, spatial and ethical orientation. The temporal element relates to the link between generations: those who lived before us have created the foundation upon which we are building our well-being today. Similarly, the choices we make today will affect the lives of generations to come – whether we like it or not.
The spatial element, in turn, is about how the foundation of our well-being is largely built on resources from outside our own area. Nowadays, our everyday life is typically connected to the lives and environments of people in faraway places.
“We often oversimplify reality by thinking in point-like manner, for example that electricity comes from the socket, water from the tap, and jeans from the store,” Professor Arto O. Salonen of the University of Eastern Finland, the first author of the article introducing the Planetary Inclusion Scale, notes.
The Planetary Inclusion Scale also involves the idea of broader ethical thinking. Transcending the human-biosphere boundary in life-preserving ways is increasingly important.
Evaluating personal beliefs and experiences helps to become aware of one’s planetary relationship. The nature of this relationship is increasingly central when seeking solutions to climate change, biodiversity loss and the depletion of natural resources.
The Planetary Inclusion Scale works in such a way that the respondent evaluates their life as a whole by considering the following statements, for example, on a scale of 1–7.
- I feel that my presence in the world is significant.
- I believe that those who will live after me will be satisfied with my choices.
- I feel I do not belong only in a community or a nation, but on a single and finite planet.
- I believe that the planet needs me to preserve future opportunities for a good life.
- I can influence the intertwined future of me and the planet.
- I experience meaningfulness.
- I am engaged in broadening my sphere of care.
- I belong to the world that supports my life.
- I live in peace and harmony with the world.
- I am part of the intergenerational chain and contribute to the world to make it a better place.
The strength of the Planetary Inclusion Scale lies in its ability to make visible the diverse ways in which humans are connected to their surrounding world. Each of the connections identified can give meaning to life, increase experiences of belonging and inclusion, expand the sphere of care, and raise awareness of one’s own possibilities for influence.
Social inclusion and having a sense of belonging with other people are key elements of a good life. However, the fate of humanity is a challenge that extends beyond our social reality. Experiences of belonging and inclusion, understood in a broader sense than before, may be crucial for a sustainable future.
In an article published in International Journal of Social Pedagogy, a team of researchers propose a new Planetary Inclusion Scale that structures our planetary relationship three-dimensionally based on temporal, spatial and ethical orientation. The temporal element relates to the link between generations: those who lived before us have created the foundation upon which we are building our well-being today. Similarly, the choices we make today will affect the lives of generations to come – whether we like it or not.
The spatial element, in turn, is about how the foundation of our well-being is largely built on resources from outside our own area. Nowadays, our everyday life is typically connected to the lives and environments of people in faraway places.
“We often oversimplify reality by thinking in point-like manner, for example that electricity comes from the socket, water from the tap, and jeans from the store,” Professor Arto O. Salonen of the University of Eastern Finland, the first author of the article introducing the Planetary Inclusion Scale, notes.
The Planetary Inclusion Scale also involves the idea of broader ethical thinking. Transcending the human-biosphere boundary in life-preserving ways is increasingly important.
Evaluating personal beliefs and experiences helps to become aware of one’s planetary relationship. The nature of this relationship is increasingly central when seeking solutions to climate change, biodiversity loss and the depletion of natural resources.
The Planetary Inclusion Scale works in such a way that the respondent evaluates their life as a whole by considering the following statements, for example, on a scale of 1–7.
- I feel that my presence in the world is significant.
- I believe that those who will live after me will be satisfied with my choices.
- I feel I do not belong only in a community or a nation, but on a single and finite planet.
- I believe that the planet needs me to preserve future opportunities for a good life.
- I can influence the intertwined future of me and the planet.
- I experience meaningfulness.
- I am engaged in broadening my sphere of care.
- I belong to the world that supports my life.
- I live in peace and harmony with the world.
- I am part of the intergenerational chain and contribute to the world to make it a better place.
The strength of the Planetary Inclusion Scale lies in its ability to make visible the diverse ways in which humans are connected to their surrounding world. Each of the connections identified can give meaning to life, increase experiences of belonging and inclusion, expand the sphere of care, and raise awareness of one’s own possibilities for influence.
JOURNAL
International Journal of Social Pedagogy
International Journal of Social Pedagogy
DOI
ARTICLE TITLE
Who and what belongs to us? Towards a comprehensive concept of inclusion and planetary citizenship
Who and what belongs to us? Towards a comprehensive concept of inclusion and planetary citizenship
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