Life, Energy, Dynamics and Dark Matter - Exploring X-rays from the Outer Planets
Lead Research Organisation:
UNIVERSITY COLLEGE LONDON
Department Name: Physics and Astronomy
Abstract
The outer solar system is truly a place of wonders: spectacular auroral displays, so energetic that they could power Human civilization; moons with global sub-surface water oceans - potentially perfect environments for life; magnetic bubbles ('magnetospheres') that are the largest coherent structures in the solar system; intense radiation belts filled with particles so energetic that they travel at close to the speed of light; iconic glistening rings extending 20 times the diameter of Earth into space to encircle their gaseous hosts. How the cosmos creates these marvels and what processes govern them is at the heart of solar system science and this research.
Historically, NASA and ESA's flagship X-ray observatories, Chandra and XMM-Newton, have been widely used to study the unimaginably energetic or large (black holes, neutron stars or the gas that flows between galaxies). However, X-ray observatories also provide invaluable and under-utilised insights into planetary bodies. My research aims to ensure that we fully utilise the diverse range of X-ray capabilities to study the outer planets.
X-rays fluorescence is a process that produces 'fingerprint' signatures of atomic elements. Consequently, it is excellent for determining what atomic elements something is composed of. On Earth, X-ray fluorescence is used for everything from determining whether a piece of art is fake, to identifying lead in paint, chlorine in food and metals in cosmetics. Through the ERF, I will study X-ray fluorescence from Jupiter's moons Io, Europa, Ganymede and Callisto. This will identify which elements are most common on their icy surfaces, distinguishing between different salts in Europa's ocean to identify what conditions are available there for potential life.
Europa orbits Jupiter within Jupiter's magnetosphere. This vast magnetic cavity around the planet forms through the combination of Jupiter's rapid-rotation, strong magnetic field, and the constant injections of plasma (ionised particles) from the volcanoes on Jupiter's moon, Io. Plasma makes up 99% of the observed Universe. Understanding what processes govern the behaviours of plasmas is therefore critical to understanding the matter we observe across the cosmos. I will use X-ray observations in tandem with measurements by spacecraft in orbit at the planets to study these fundamental plasma processes in several ways:
1. exploring Jupiter's dancing auroral displays to probe the flows of particles and the processes that control them
2. analysing X-ray images of the intense radiation belts to determine how they change over time and what processes trigger these changes
3. calculating the X-ray emissions along the boundary between the magnetospheres of Jupiter, Saturn, Uranus and Neptune and the solar wind, laying foundations to take videos of this boundary, to study the global relationship between each planet and its surrounding space envrionment (the solar wind).
The study of exoplanets has shown that Ice Giants are amongst the most common type of planet in the Universe. However, our local Ice Giants, Uranus and Neptune, are very poorly understood. The rapid flybys of the Voyager spacecraft in the 1980s are the only visit we have ever made to either planet. Without any near-term plans to visit these planets, we have to study them through telescopes at Earth. I will seek to acquire new X-ray observing time for Uranus. This will enable us to explore many of the exciting hints suggested by previous observations, testing for the presence of: sparkling X-ray aurorae, the X-ray glow of the rings and potential fluorescence from the atmosphere.
Through these diverse projects, the research programme will usher in a revolution in the uses of X-ray observations for the outer solar system, founding new research fields and leveraging the X-ray waveband to provide unique insights into the mysterious and wonderous worlds in the outer regions of our solar system.
Historically, NASA and ESA's flagship X-ray observatories, Chandra and XMM-Newton, have been widely used to study the unimaginably energetic or large (black holes, neutron stars or the gas that flows between galaxies). However, X-ray observatories also provide invaluable and under-utilised insights into planetary bodies. My research aims to ensure that we fully utilise the diverse range of X-ray capabilities to study the outer planets.
X-rays fluorescence is a process that produces 'fingerprint' signatures of atomic elements. Consequently, it is excellent for determining what atomic elements something is composed of. On Earth, X-ray fluorescence is used for everything from determining whether a piece of art is fake, to identifying lead in paint, chlorine in food and metals in cosmetics. Through the ERF, I will study X-ray fluorescence from Jupiter's moons Io, Europa, Ganymede and Callisto. This will identify which elements are most common on their icy surfaces, distinguishing between different salts in Europa's ocean to identify what conditions are available there for potential life.
Europa orbits Jupiter within Jupiter's magnetosphere. This vast magnetic cavity around the planet forms through the combination of Jupiter's rapid-rotation, strong magnetic field, and the constant injections of plasma (ionised particles) from the volcanoes on Jupiter's moon, Io. Plasma makes up 99% of the observed Universe. Understanding what processes govern the behaviours of plasmas is therefore critical to understanding the matter we observe across the cosmos. I will use X-ray observations in tandem with measurements by spacecraft in orbit at the planets to study these fundamental plasma processes in several ways:
1. exploring Jupiter's dancing auroral displays to probe the flows of particles and the processes that control them
2. analysing X-ray images of the intense radiation belts to determine how they change over time and what processes trigger these changes
3. calculating the X-ray emissions along the boundary between the magnetospheres of Jupiter, Saturn, Uranus and Neptune and the solar wind, laying foundations to take videos of this boundary, to study the global relationship between each planet and its surrounding space envrionment (the solar wind).
The study of exoplanets has shown that Ice Giants are amongst the most common type of planet in the Universe. However, our local Ice Giants, Uranus and Neptune, are very poorly understood. The rapid flybys of the Voyager spacecraft in the 1980s are the only visit we have ever made to either planet. Without any near-term plans to visit these planets, we have to study them through telescopes at Earth. I will seek to acquire new X-ray observing time for Uranus. This will enable us to explore many of the exciting hints suggested by previous observations, testing for the presence of: sparkling X-ray aurorae, the X-ray glow of the rings and potential fluorescence from the atmosphere.
Through these diverse projects, the research programme will usher in a revolution in the uses of X-ray observations for the outer solar system, founding new research fields and leveraging the X-ray waveband to provide unique insights into the mysterious and wonderous worlds in the outer regions of our solar system.
People |
ORCID iD |
| William Dunn (Principal Investigator / Fellow) |
Publications
Ballard C
(2023)
Testing the Limits of Biosignature Detection in Ca-sulphate Mixtures Through a Simulated Martian Environment
in Research Notes of the AAS
D. Küntz K
(2024)
The magnetosheath at high spectral resolution
in Earth and Planetary Physics
Dunn W
(2023)
Exploring Fundamental Particle Acceleration and Loss Processes in Heliophysics through an Orbiting X-ray Instrument in the Jovian System
in Bulletin of the AAS
Dunn W
(2022)
Handbook of X-ray and Gamma-ray Astrophysics
Dunn W
(2022)
Handbook of X-ray and Gamma-ray Astrophysics
Dunn WR
(2022)
Jupiter's X-Ray and UV Dark Polar Region.
in Geophysical research letters
Feng E
(2023)
Variation of the Jovian Magnetopause Under Constant Solar Wind Conditions: Significance of Magnetodisc Dynamics
in Geophysical Research Letters
Gu W
(2023)
A Survey of Magnetic Field Line Curvature in Jovian Dawn Magnetodisc
in Geophysical Research Letters
Gu W
(2023)
Hourly Periodic Variations of Ultralow-Frequency (ULF) Waves in Jupiter's Magnetosheath
in Journal of Geophysical Research: Planets
McEntee S
(2023)
Long Exposure Chandra X-Ray Observation of Jupiter's Auroral Emissions During Juno Plasmasheet Encounters in September 2021
in Journal of Geophysical Research: Space Physics
| Description | COMPASS - a ~$bn NASA Heliophysics Decadal mission to Jupiter's radiation belts |
| Organisation | Johns Hopkins University |
| Department | Applied Physics Laboratory (APL) |
| Country | United States |
| Sector | Charity/Non Profit |
| PI Contribution | The mission in general can be found here https://essopenarchive.org/users/523674/articles/625700-comprehensive-observations-of-magnetospheric-particle-acceleration-sources-and-sinks-compass-a-mission-concept-to-jupiter-s-extreme-magnetosphere-to-address-fundamental-mysteries-in-heliophysics I lead the X-ray science case for the mission. See white paper: https://arxiv.org/ftp/arxiv/papers/2303/2303.02161.pdf |
| Collaborator Contribution | Designed the science and instrumentation for a spacecraft to Jupiter's radiation belts that is currently in consideration for NASA's Heliophysics Decadal. |
| Impact | Mission proposal and 4 white papers. |
| Start Year | 2022 |
| Description | Line Emission Mapper (https://www.lem-observatory.org/). A proposed spacecraft for NASA's $bn AEPEX call. |
| Organisation | Harvard University |
| Department | Harvard-Smithsonian Center for Astrophysics |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | Within the LEM team (a collaboration of 200+ astrophysicists supporting a new X-ray telescope with high (~1 eV) spectral resolution), I chair the planetary working group (30 members). |
| Collaborator Contribution | Simulated LEM observations of planetary bodies across the Solar System. Exploring the science possibilities of LEM for planetary bodies. See white paper for details: https://arxiv.org/abs/2310.13873 |
| Impact | We submitted a highly competitive funding proposal and suite of supporting white papers and peer-reviewed papers that explore the science possible with the LEM mission. LEM white paper is here: https://arxiv.org/abs/2211.09827 The solar system white paper for LEM is here : https://arxiv.org/abs/2310.13873 We also have 3 further papers in support of LEM solar system science in review and two published. |
| Start Year | 2022 |
| Description | Orbyts www.orbyts.org |
| Organisation | Northumbria University |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | I coordinate the Orbyts programme, overseeing delivery of 100+ research-with-schools projects. Organising and delivering training for design and delivery of research-with-school projects. Applying for and managing grants to facilitate it. Evaluating and improving the programme. Supporting researchers throughout. Pairing researchers with schools. Defining standard operating procedures. Organising and facilitating the conferences. |
| Collaborator Contribution | Design and delivery of research-with-schools projects |
| Impact | Delivery of 100+ research with schools projects 100% increases in girls taking A-level physics following Orbyts at GCSE Significant enhancements in uptake of STEM subjects amongst students from groups historically excluded from science (e.g. those from low income backgrounds). ~20 publications including ~250 school students as (co)authors. |
| Start Year | 2022 |
| Description | UK X-ray instrumentation for an outer planets spacecraft |
| Organisation | University of Leicester |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | I created an annual workshop for the UK community to support an X-ray instrument (like that on the ESA SMILE or BepiColombo missions) for the outer planets. The partnership includes the teams that built those instruments and collects the outer planets science community across the UK. |
| Collaborator Contribution | An annual workshop, conference presentations and funding proposals to support design and delivery of an X-ray instrument for a future Jupiter or Uranus mission. e.g. https://discovery.ucl.ac.uk/id/eprint/10182501/ |
| Impact | A white paper for the STFC roadmap A suite of conference presentations e.g. at the NASA JPL Uranus Flagship mission meeting. |
| Start Year | 2022 |
| Description | Coordinated and grew the Orbyts programme (inter)nationally for the last 6 years |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Schools |
| Results and Impact | Science faces systemic diversity issues (e.g. post-16 physics is <20% girls; low-income background and Black students are highly underrepresented). The UK also faces chronic shortages of science teachers (1 in 7 schools does not have a physics teacher) leading to ongoing damaging skill shortfalls. How Orbyts works To address these problems, Orbyts creates partnerships between scientists and schools, which facilitate school students to undertake their own original space research. The researcher acts as a relatable role model, having an 'immensely humanising impact' on perceptions of science and scientists, and empowering students to engage in STEM pathways in the long term. The average group is 10-20 students, who meet their research mentor ~14 times over two terms. Example project student videos: https://www.orbyts.org/how-does-jupiter-produce-such-powerful-n https://www.orbyts.org/mapping-accelerated-electrons-throughout https://www.orbyts.org/exploring-the-x-ray-emitting-outflowing Critically, school teachers report that without Orbyts's partnership model they would not have time, subject expertise and/or the confidence to deliver these types of projects. Consequently, Orbyts caters directly to schools that cannot undertake similar programmes (e.g. the excellent IRIS). Orbyts is an initiative that takes the burden of running impactful student research projects off of time-starved, overworked teachers, while providing them with unique Continuous Professional Development (CPD) opportunities. To ensure Orbyts primarily works with those historically excluded from science, we require that Orbyts groups are 50+% pupil premium (PP) and 50+% girls, and target schools with high numbers of underserved students. E.g. the Orbyts STAR pilot at Great Ormond Street Hospital. Impact This structure of regular interventions, relatable role models and active ownership of scientific research is proving to be transformative. Evaluation shows that Orbyts is significantly increasing science capital and STEM inclusivity. It is rare for STEM engagement programmes to maintain a high retention. 24 of the 25 schools on the 2021 UKSA funding have already requested Orbyts projects for this year (alongside 30+ other schools). Impact on Students: Schools report 100% increases in A-level physics uptake by girls when Orbyts is run with GCSE classes. The programme also directly impacts science capital and attainment, e.g groups scored in the top 1% value added from GCSE to A-level. Since 2018, Orbyts has enabled 250+ school students to author published scientific papers (see https://www.orbyts.org/researchprojects-publications). Most of these students are from groups historically excluded from science: alongside PP and gender requirements, Orbyts papers have authorship amongst the most ethnically diverse in physics. Students from the Orbyts pilot project at Highams Park school, despite their socio-economic challenges, have gone on to PhDs, and one (Megan Joseph) delivered her own Orbyts project last year - completing the circle. Megan cites Orbyts as why she went to University. From the same Orbyts cohort, Menghan Liu became a physics teacher and requested Orbyts in her school because of its profound impact on her. From our current cohort, one SEND year 10 student said about her experience at the end-of-year Orbyts conference: "People enjoyed our findings, asked interesting questions and made intrigued observations. Knowledgeable students who'd been studying Astrophysics far longer than we had looked to us for guidance. Suddenly, I didn't feel so out of place anymore." On Orbyts impact teacher Becky Parker MBE says: "No other scheme comes close to achieving the diversity and breadth of student engagement which then translates to genuine STEM futures and teacher retention." Impact on Teachers: Alongside retention, our partner teachers report a wide secondary impact on subject knowledge and the community - chemistry teacher D. Fleming says: "In a tough year with significant professional challenges, this has been a real "get me out of bed in the morning" project. When our partner researcher first explained the project to the students, I was whiteboarding to help them see keywords and draw together threads. After, I stood back and said to myself "this is literally the coolest thing I've ever written on a whiteboard". The project has fed through the school with Orbyts members presenting to lower year groups and it's even changed my teaching to my year 8s - all my magnetism stuff is now fed through the lens of the importance of our magnetic field and what Earth's aurora tells us. Multiple staff have become involved and had valuable subject knowledge gains and through the school publications the wider school community - parents have also become enthused and are talking with their children about the project even if they're not directly involved. Orbyts is definitely one of the coolest things I've been exposed to in my 15 year career." Impact on Researchers: Orbyts runs an extensive researcher training programme, through which expertled sessions embed evidence-based practice for inclusivity, teaching, communication and management within University research groups. Consequently, through Orbyts, the next generation of UK lecturers and spacecraft leaders are given the firmest foundations for pedagogy and management training, often unavailable within a PhD/PDRA. Through this ongoing professional development and quality assurance, we enable the development and dissemination of world-leading best practice. |
| Year(s) Of Engagement Activity | 2022,2023 |
| URL | http://www.orbyts.org |