Studies on Planetary Formation and Evolution at Bristol
Lead Research Organisation:
University of Bristol
Department Name: Earth Sciences
Abstract
The proposed work follows the development of planetary bodies from formation of their raw materials to the functioning of their atmospheres. Our attention starts with the earliest solar system, when the only fine grained material was present around the sun. We will both look at the distribution of a key radioactive nuclide in this nebula and the separation of gas from solid at the beginnings of planet formation. This will tell us about the compositions of planets likely to form and whether or not they will melt extensively.
A major event in the history of a growing planet is the sinking of metal to its centre, forming a core. This is well understood on Earth, but not for smaller planetary bodies. We will use a novel, isotopic measure of the size of cores in one of the largest asteroids (Vesta), the Moon and Mars. This new approach is made possible by our ability to make precision isotopic measurements and couple them with melting experiments in the lab. The idea behind this approach is that we have few samples of these planetary bodies and the techniques used on Earth do not work well for such samples, which have experienced unknown perturbation en route to the surface. We have strong reason to believe this does not occur for Ni isotopes and so they record a robust signal of core formation in small bodies.
Although the formation of some small planetary bodies, like Vesta, is thought to be well understood, the origin of our closest companion, the Moon has long proven problematic. What appeared successful models of its dynamics fail to account for its marked chemical similarity with the Earth. To address this a new suite of models have been proposed, which represent a radical departure in the style of formation. However, it is still not know how the Moon actually forms from the vapour cloud formed in such collisions. This is the focus of our fourth project which will further see if the new models can also explain the identical isotopic compositions of Earth and Moon.
The interior of the Earth is difficult to probe, but the dynamics of the Moon's interior is yet harder. Seismic techniques are used on Earth and there are some seismic records of the Moon. These noisey data are difficult to process, but advances in processing terrestrial data make it time to re-examine the information carried in the lunar archive. In particular, the project will look for anisotropy- caused by the preferential alignment of objects. This has proven very successful on Earth and may reveal a more detailed picture of motions within the lunar interior and whether or not this relates to obvious features on the surface.
Finally our planetary exploration focuses on the active atmosphere of Saturn's satellite Titan. Using spectroscopic observations from spacecraft and new, high-resolution, ground-based data, the project will examine the distribution of oxygen bearing molecules in Titan's atmosphere and use this information to test models of the processes that produce and move these species. This will provide a window into understanding the active atmosphere of a distant planetary body.
A major event in the history of a growing planet is the sinking of metal to its centre, forming a core. This is well understood on Earth, but not for smaller planetary bodies. We will use a novel, isotopic measure of the size of cores in one of the largest asteroids (Vesta), the Moon and Mars. This new approach is made possible by our ability to make precision isotopic measurements and couple them with melting experiments in the lab. The idea behind this approach is that we have few samples of these planetary bodies and the techniques used on Earth do not work well for such samples, which have experienced unknown perturbation en route to the surface. We have strong reason to believe this does not occur for Ni isotopes and so they record a robust signal of core formation in small bodies.
Although the formation of some small planetary bodies, like Vesta, is thought to be well understood, the origin of our closest companion, the Moon has long proven problematic. What appeared successful models of its dynamics fail to account for its marked chemical similarity with the Earth. To address this a new suite of models have been proposed, which represent a radical departure in the style of formation. However, it is still not know how the Moon actually forms from the vapour cloud formed in such collisions. This is the focus of our fourth project which will further see if the new models can also explain the identical isotopic compositions of Earth and Moon.
The interior of the Earth is difficult to probe, but the dynamics of the Moon's interior is yet harder. Seismic techniques are used on Earth and there are some seismic records of the Moon. These noisey data are difficult to process, but advances in processing terrestrial data make it time to re-examine the information carried in the lunar archive. In particular, the project will look for anisotropy- caused by the preferential alignment of objects. This has proven very successful on Earth and may reveal a more detailed picture of motions within the lunar interior and whether or not this relates to obvious features on the surface.
Finally our planetary exploration focuses on the active atmosphere of Saturn's satellite Titan. Using spectroscopic observations from spacecraft and new, high-resolution, ground-based data, the project will examine the distribution of oxygen bearing molecules in Titan's atmosphere and use this information to test models of the processes that produce and move these species. This will provide a window into understanding the active atmosphere of a distant planetary body.
Planned Impact
There are important industrial applications of both chemical (isotopic), physical and numerical approaches developed in this proposal.
Links with industry in all of these disciplines is well established within the group at Bristol, which allow for ready impact.
Namely, the isotope lab works closely with a major instrument manufacturer (Thermo Fisher, Bremen) and is currently exploring the possibility of commercialising a novel mass-spectrometer built in collaboration between these two parties.
Bristol runs regular meetings between industrial and academic seismologists (BUMPS) which show cases new techniques and has provided an important conduit for successful developments to be adopted by industry. Programming which forms part of this work will directly feed into commercial applications from small spin out companies to the insurance industry.
The group at Bristol is very active in Outreach, from major public events at the University (e.g. the annual Colin Pillinger lecture), to advising the media (through BBC Bristol and related outlets) and giving guidance about purported meteorite finds. We have a well organised programme to engage with local schools, organised centrally through the University. This ranges from hosting secondary school summer project students to awe-inspiring show-and-tell in primary schools. We hope to have further influence by rolling out some of our materials using the GeoBus- funded by another RCUK programme but with which we have close links.
Links with industry in all of these disciplines is well established within the group at Bristol, which allow for ready impact.
Namely, the isotope lab works closely with a major instrument manufacturer (Thermo Fisher, Bremen) and is currently exploring the possibility of commercialising a novel mass-spectrometer built in collaboration between these two parties.
Bristol runs regular meetings between industrial and academic seismologists (BUMPS) which show cases new techniques and has provided an important conduit for successful developments to be adopted by industry. Programming which forms part of this work will directly feed into commercial applications from small spin out companies to the insurance industry.
The group at Bristol is very active in Outreach, from major public events at the University (e.g. the annual Colin Pillinger lecture), to advising the media (through BBC Bristol and related outlets) and giving guidance about purported meteorite finds. We have a well organised programme to engage with local schools, organised centrally through the University. This ranges from hosting secondary school summer project students to awe-inspiring show-and-tell in primary schools. We hope to have further influence by rolling out some of our materials using the GeoBus- funded by another RCUK programme but with which we have close links.
Publications
Cordiner M
(2020)
Detection of Dynamical Instability in Titan's Thermospheric Jet
in The Astrophysical Journal Letters
Cordiner M
(2018)
Interferometric Imaging of Titan's HC 3 N, H 13 CCCN, and HCCC 15 N
in The Astrophysical Journal Letters
Cordiner M
(2019)
ALMA Spectral Imaging of Titan Contemporaneous with Cassini 's Grand Finale
in The Astronomical Journal
Gregory T
(2020)
Primordial formation of major silicates in a protoplanetary disc with homogeneous 26Al/27Al.
in Science advances
Irwin P
(2018)
Detection of hydrogen sulfide above the clouds in Uranus's atmosphere
in Nature Astronomy
Irwin P
(2023)
Latitudinal Variations in Methane Abundance, Aerosol Opacity and Aerosol Scattering Efficiency in Neptune's Atmosphere Determined From VLT/MUSE
in Journal of Geophysical Research: Planets
Irwin P
(2023)
Spectral determination of the colour and vertical structure of dark spots in Neptune's atmosphere
in Nature Astronomy
Irwin P
(2024)
Modelling the seasonal cycle of Uranus's colour and magnitude, and comparison with Neptune
in Monthly Notices of the Royal Astronomical Society
Irwin P
(2019)
Probable detection of hydrogen sulphide (H2S) in Neptune's atmosphere
in Icarus
Irwin PGJ
(2022)
Hazy Blue Worlds: A Holistic Aerosol Model for Uranus and Neptune, Including Dark Spots.
in Journal of geophysical research. Planets
James A
(2023)
The Temporal Brightening of Uranus' Northern Polar Hood From HST/WFC3 and HST/STIS Observations
in Journal of Geophysical Research: Planets
Lombardo N
(2019)
Ethane in Titan's Stratosphere from Cassini CIRS Far- and Mid-infrared Spectra
in The Astronomical Journal
Lombardo N
(2019)
Detection of Propadiene on Titan
in The Astrophysical Journal Letters
Luu T
(2019)
Bulk chondrite variability in mass independent magnesium isotope compositions - Implications for initial solar system 26Al/27Al and the timing of terrestrial accretion
in Earth and Planetary Science Letters
Mitchell D
(2021)
Polar Vortices in Planetary Atmospheres
in Reviews of Geophysics
Nixon C
(2021)
Erratum: "Cassini Composite Infrared Spectrometer (CIRS) Observations of Titan 2004-2017" (2019, ApJS, 244, 14)
in The Astrophysical Journal Supplement Series
Nixon C
(2020)
Detection of Cyclopropenylidene on Titan with ALMA
in The Astronomical Journal
Nixon C
(2019)
Cassini Composite Infrared Spectrometer (CIRS) Observations of Titan 2004-2017
in The Astrophysical Journal Supplement Series
Sharkey J
(2021)
Potential vorticity structure of Titan's polar vortices from Cassini CIRS observations
in Icarus
Description | In the cosmochemical component of this consolidated award we made two major achievements in constraining the distribution of 26Al in the proto-solar nebula, the key goal of the project. Firstly, we made very high precision (<±5ppm, 2se) Mg isotope analyses of bulk primitive meteorites, which showed a striking, linear trend against their measured Al/Mg ratios [Luu et al, EPSL 2019]. This array can be interpreted as an isochron, with the slope yielding the initial 26Al26Al of the samples. Critically, ordinary and carbonaceous chondrites plot on the same array as calcium aluminium rich inclusions (CAI), implying a constant initial 26Al/27Al in these diverse samples, in marked contrast to recent suggestions of solar system 26A/27Al heterogeneity. Secondly, we successfully identified, micro-sampled and analysed for their Mg isotopic composition rare, highly Mg rich olivines from carbonaceous chondrites. The bulk compositions of these olivines imply their early formation. Remarkably, our Mg isotope analyses showed that they were as unradiogenic as values predicted for the initial compositions of CAI. Not only does this document the great antiquity of these objects (as old as the oldest solar system objects), but it shows that the material from which carbonaceous chondrites formed had initial 26Al/27Al as elevated as CAI. Again this is contrary to recent notions that the 'canonical' 26Al/27Al ratios of ~5x10-5 are only found in CAI. These two findings represent major contributions towards understanding the much debated distribution of 26Al in the solar system. In the work on planetary atmospheres, significant new insights were gained into the external flux processes, formation, atmospheric composition and internal structure of the solar system ice giants. |
Exploitation Route | The work highlighted the importance of refractory olivine grains as a key early component of primitive meteorites. Further study on these objects is warranted and is the basis of on-going STFC work. |
Sectors | Chemicals Environment |
Description | Atmospheric states can be useful for mission planning / future entry probes The high precision isotope analyses made in this project are of increasing interest with the UK nuclear industry, which is looking for new ways to monitor the nuclear fuel cycle in the increased demand in the clean energy transition. We have engaged with NNL in order to facilitate efficient skills transfer. |
First Year Of Impact | 2020 |
Sector | Aerospace, Defence and Marine,Education,Energy |
Impact Types | Economic |
Description | (EROS) - ExploRing the surface slopes Of aSteroids |
Amount | € 224,933 (EUR) |
Funding ID | 837894 |
Organisation | European Commission |
Sector | Public |
Country | European Union (EU) |
Start | 01/2020 |
End | 12/2021 |
Title | Titan atmospheric temperature and composition database from Cassini |
Description | Titan atmospheric temperature and composition database from Cassini |
Type Of Material | Database/Collection of data |
Year Produced | 2019 |
Provided To Others? | Yes |
Impact | Use by other researchers and modellers |
URL | https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL081401 |
Description | ETH Zurich |
Organisation | ETH Zurich |
Country | Switzerland |
Sector | Academic/University |
PI Contribution | Neptune and Mars observation analysis |
Collaborator Contribution | Modelling and data products |
Impact | Publications |
Start Year | 2020 |
Title | NEMESIS/Radtrancode Software |
Description | Radiative transfer analysis code |
Type Of Technology | Software |
Year Produced | 2020 |
Open Source License? | Yes |
Impact | Many publications |
Description | Access to Bristol widening participation event |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Schools |
Results and Impact | Activities around geophysics for school age children. Encourage widening participation in HE sector. |
Year(s) Of Engagement Activity | 2019 |
Description | Gave Public Lecture at Geology Society of London |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Professional Practitioners |
Results and Impact | The Public Lectures are presented in Burlington House, London with an afternoon and evening sitting to attract different audiences (afternoon to attract schools and evening to attract professionals). Both talks were given to a near full auditorium of ~100 people. |
Year(s) Of Engagement Activity | 2019 |
URL | https://www.geolsoc.org.uk/gslpubliclectures19 |
Description | Ice giant debate at EPSC |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Invited debate participant |
Year(s) Of Engagement Activity | 2022 |
Description | Ice giants invited talk |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Invited talk / webinar |
Year(s) Of Engagement Activity | 2022 |
URL | https://neptuneodyssey.jhuapl.edu/Events/ |
Description | Interview for the podcast Curious About |
Form Of Engagement Activity | A broadcast e.g. TV/radio/film/podcast (other than news/press) |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Interview for the podcast Curious About, about my work as a planetary scientist (Melody Sylvestre) |
Year(s) Of Engagement Activity | 2018 |
URL | https://cap.podbean.com/e/physics-1534576936 |
Description | Interview for the podcast Curious About |
Form Of Engagement Activity | Engagement focused website, blog or social media channel |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | Interview for the podcast Curious About. Careers and science focus. (Melody Sylvestre) |
Year(s) Of Engagement Activity | 2018 |
URL | https://cap.podbean.com/e/physics-1534576936/ |
Description | Interview for the podcast La Science en Chemin by the French astronomy magazine Ciel & Espace |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Interview for the podcast La Science en Chemin by the French astronomy magazine Ciel & Espace, about my work, my studies, and my outreach activities (Melody Sylvestre) |
Year(s) Of Engagement Activity | 2019 |
URL | https://www.cieletespace.fr/actualites/podcast-la-science-en-chemin-avec-melody-sylvestre |
Description | New Scientist interview (Cerberus Fossae paper) |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | Interview on recent paper results |
Year(s) Of Engagement Activity | 2022 |
URL | https://www.newscientist.com/article/2344445-quakes-on-mars-reveal-there-may-be-magma-beneath-the-su... |
Description | Organization and hosting of the festival "De La Plage aux Étoiles" in Collioure (France) |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | Organization and hosting of the festival "De La Plage aux Étoiles" in Collioure (France). It is an astrophysics outreach festival with exhibitions, conferences and sky observations with telescopes. (Melody Sylvestre) |
Year(s) Of Engagement Activity | 2018 |
URL | https://www.astrocollioure.fr/spip/ |
Description | Organization and hosting of the festival "De La Plage aux Étoiles" in Collioure (France) |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Organization and hosting of the festival "De La Plage aux Étoiles" in Collioure (France) (Melody Sylvestre) |
Year(s) Of Engagement Activity | 2019 |
Description | Outreach conference about Cassini for the amateur astronomy club Janus in Gennevilliers (France) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | Outreach conference about Cassini for the amateur astronomy club Janus in Gennevilliers (France) (Melody Sylvestre) |
Year(s) Of Engagement Activity | 2018 |
Description | Outreach conference about Cassini for the amateur astronomy club Janus in Gennevilliers (France) |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Outreach conference about Cassini for the amateur astronomy club Janus in Gennevilliers (France) (Melody Sylvestre) |
Year(s) Of Engagement Activity | 2019 |
Description | Press release on Titan research |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | press release |
Year(s) Of Engagement Activity | 2019 |
URL | https://blogs.agu.org/geospace/2019/04/11/extended-winter-polar-vortices-chill-saturns-strangely-fam... |
Description | Researchers' Tales which was a part of FUTURES: European Researchers Night |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | Researchers' Tales which was a part of FUTURES: European Researchers Night |
Year(s) Of Engagement Activity | 2020 |
Description | Sustainable Offworld Network |
Form Of Engagement Activity | A formal working group, expert panel or dialogue |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Sustainable Offworld Network |
Year(s) Of Engagement Activity | 2020 |
URL | https://sonet-hub.com |
Description | UOB Earth Sciences Work Experience Virtual lecture/discussion |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Schools |
Results and Impact | UOB Earth Sciences Work Experience Virtual lecture/discussion |
Year(s) Of Engagement Activity | 2020 |