Exoplanets in 3D: Interpreting 3D planets using 1D spectra
Lead Research Organisation:
The Open University
Department Name: Faculty of Sci, Tech, Eng & Maths (STEM)
Abstract
Satellite images of the planets in our Solar System reveal dynamic, changing worlds. Jupiter's poles are now known to be unexpectedly blue, contrasting with the equator, and the great red spot is gradually shrinking. Recently, we have also started to find out more about planets orbiting other stars - exoplanets. Studying exoplanets is exciting because it provides context for the evolution of Solar System planets, but also involves several challenges.
Only rarely can we directly observe an exoplanet, because stars are so much larger and brighter. Instead, we measure the dip in the amount of light coming from the parent star when the planet passes in front. Gases and cloud particles absorb and scatter particular colours - or wavelengths - of light, so by measuring precisely the amount of light blocked by the planet at each wavelength, we can identify the unique fingerprints of substances in the planet's atmosphere - all without seeing the planet!
However, there's a catch: we only get a single measurement averaged over the whole of the planet's visible atmosphere, which is not uniform and changes with time. To truly compare exoplanets with Solar System worlds, we need to understand what this average measurement actually represents. I aim to investigate, using computational models of light passing through an atmosphere, how a 3D, time-varying, cloudy exoplanet atmosphere can best be studied using these measurements. I will compare models with data from the new James Webb Space Telescope, due to be launched in 2021, which is set to provide the most detailed and precise observations of exoplanets yet.
Only rarely can we directly observe an exoplanet, because stars are so much larger and brighter. Instead, we measure the dip in the amount of light coming from the parent star when the planet passes in front. Gases and cloud particles absorb and scatter particular colours - or wavelengths - of light, so by measuring precisely the amount of light blocked by the planet at each wavelength, we can identify the unique fingerprints of substances in the planet's atmosphere - all without seeing the planet!
However, there's a catch: we only get a single measurement averaged over the whole of the planet's visible atmosphere, which is not uniform and changes with time. To truly compare exoplanets with Solar System worlds, we need to understand what this average measurement actually represents. I aim to investigate, using computational models of light passing through an atmosphere, how a 3D, time-varying, cloudy exoplanet atmosphere can best be studied using these measurements. I will compare models with data from the new James Webb Space Telescope, due to be launched in 2021, which is set to provide the most detailed and precise observations of exoplanets yet.
Organisations
Publications
Ahrer EM
(2023)
Early Release Science of the exoplanet WASP-39b with JWST NIRCam.
in Nature
Alderson L
(2023)
Early Release Science of the exoplanet WASP-39b with JWST NIRSpec G395H.
in Nature
Banerjee A
(2023)
Effect of centrifugal force on transmission spectroscopy of exoplanet atmospheres
in Monthly Notices of the Royal Astronomical Society: Letters
Barstow J
(2021)
The curse of clouds
in Astronomy & Geophysics
Bell Taylor J.
(2024)
Nightside clouds and disequilibrium chemistry on the hot Jupiter WASP-43b
in arXiv e-prints
Feinstein AD
(2023)
Early Release Science of the exoplanet WASP-39b with JWST NIRISS.
in Nature
Fortney J
(2021)
ExoFrontiers - Big questions in exoplanetary science
Gressier A
(2023)
The Hubble PanCET program: The near-ultraviolet transmission spectrum of WASP-79b
in Astronomy & Astrophysics
Description | Article for The Conversation |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | I was approached to write an article on free-floating planets for The Conversation. The opportunity is provided for comment and further engagement below the article. |
Year(s) Of Engagement Activity | 2022 |
URL | https://theconversation.com/rogue-planets-how-wandering-bodies-in-interstellar-space-ended-up-on-the... |
Description | Article for The Conversation - 4 ways JWST might detect evidence for alien life |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | I was approached by The Conversation to write an article about biosignature detection with the James Webb Space Telescope. This allowed me to describe possible signals we could find that might hint at extraterrestrial life, while also being clear that the burden of proof for this is extremely high and many biosignatures have false positives. The response to this article prompted Dr Becky to invite me onto her YouTube channel to discuss it further. I also received an interview request from Talk Radio Cape Town. |
Year(s) Of Engagement Activity | 2022 |
URL | https://theconversation.com/four-ways-to-spot-hints-of-alien-life-using-the-james-webb-space-telesco... |
Description | Article for The Conversation - James Webb Space Telescope uncovers secrets of distant world |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | I pitched and wrote a piece for The Conversation about the first results from our James Webb Space Telescope Transiting Exoplanet Community Early Release Science programme. This helped to disseminate results from our five papers and enhanced the impact of our research. |
Year(s) Of Engagement Activity | 2022 |
URL | https://theconversation.com/james-webb-space-telescope-uncovers-chemical-secrets-of-distant-world-pa... |
Description | Article for The Conversation - WASP-121b |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | I pitched and wrote an article for The Conversation on the paper for which I was a co-author looking at the phase curve and dark side of WASP-121b. |
Year(s) Of Engagement Activity | 2022 |
URL | https://theconversation.com/ruby-clouds-and-water-behaving-strangely-what-we-found-when-studying-an-... |
Description | Expert comment to media on publication of JWST ERS results |
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 | I responded to media enquiries relating to publication of our JWST Early Release Science data. I was quoted in the Guardian in August and gave an interview for BBC 3 Counties radio in November. |
Year(s) Of Engagement Activity | 2022 |
URL | https://www.theguardian.com/science/2022/aug/25/webb-telescope-zooms-in-on-planet-beyond-our-solar-s... |
Description | Interview for Dr Becky's YouTube channel on JWST and biosignature detection |
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 | I was interviewed by astronomer and YouTuber Dr Becky for her channel about the article I had written on using JWST to detect signs of alien life. We also discussed other JWST observations I am involved in. |
Year(s) Of Engagement Activity | 2022 |
URL | https://www.youtube.com/watch?v=QWTtN3NQ1Tc |
Description | Interview with Fraser Cain |
Form Of Engagement Activity | Engagement focused website, blog or social media channel |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | I was interviewed by Fraser Cain, host of the Universe Today podcast, about my research on exoplanet atmospheres. So far the interview has over 4.5k views on YouTube and is also being disseminated via Apple podcasts. Viewers who commented expressed interest in the subject matter, and stated that they had learned from the interview. |
Year(s) Of Engagement Activity | 2022 |
URL | https://www.youtube.com/watch?v=DHHo0NpdhZ8 |
Description | RAS International Day of Women and Girls in Science Talk |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | I gave a lunchtime public talk about my research as part of the Royal Astronomical Society's series on women in astronomy. |
Year(s) Of Engagement Activity | 2022 |
URL | https://www.youtube.com/watch?v=qM2joewCAvU&t=3s |
Description | School visit (Bishop Winnington Ingram) |
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 | I visited my daughter's reception class at her school to speak to the children about planets, during their topic on the Solar System. I read them a story about an alien visiting the Solar System and answered their questions about planets. I helped them to make a planet out of modelling material. |
Year(s) Of Engagement Activity | 2021 |
Description | Talk Radio Cape Town interview about detecting biosignatures. |
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 | I was interviewed on Talk Radio Cape Town (South Africa) to follow up on my article for The Conversation about finding alien life using JWST. I discussed how feasible that is likely to be, what JWST can tell us, and where we should be ideally looking if we want to find alien life. |
Year(s) Of Engagement Activity | 2022 |
Description | Zoom an astronomer chats with Turkish school students |
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 | I participated in Zoom Q&A sessions with female students studying English at a school in Turkey. They were interested in the topic of space and used it as an opportunity to practise their English language skills. The students became more engaged with astronomy and some expressed an interest in studying it in the future, when they had not done so before. |
Year(s) Of Engagement Activity | 2022 |