Professor Tom Stallard

Tom Stallard is a planetary astronomer who utilises a combination of ground-based telescopes and instruments on spacecraft to understand the upper atmospheres and ionospheres of the giant planets. 

This region of the atmosphere is fascinating because, within its thin air, we see the coupling between two grand systems. At the Sun, the driving forces that dominate the upper atmosphere come from beneath. At Earth, it is the Solar Wind outside the planet that forces energy down into the top of the atmosphere. At the giant planets, because the ionosphere collides with the neutral atmosphere, but carries and is carried by currents from the surrounding magnetosphere, these two chaotic, massive systems are forced to interact. By measuring this interaction, we can reveal the complicated nature of giant planet atmospheres, but also better understand this complex interaction in places where the atmosphere or magnetosphere typically dominate.

Beyond this work measuring the upper atmospheres of Giant Planets, he also plays an important role in the development of such missions, from driving the scientific programme before launch, through ongoing mission planning, and the detailed calibration and analysis of this data.

More broadly, he is also interested in understanding the development of life within the universe, as well as exploring how intellegent life might develop in comparison to the Anthropocene on Earth. He also works to understand and improve PhD supervision within Physics.

• Please visit the Pure Research Information Portal for further information
• Atmospheric Ion-Neutral Coupling as a Potential Driver for Saturn's Magnetospheric Antisunward Electric Field, Stallard, T. 16 Feb 2026, In: Geophysical Research Letters
• JWST Discovers the Vertical Structure of Uranus' Ionosphere, Tiranti, P., Melin, H., Moore, L., Thomas, E., Knowles, K., Stallard, T., Roberts, K., O'Donoghue, J. 28 Feb 2026, In: Geophysical Research Letters
• JWST/NIRSpec reveals the atmospheric driver of Saturn's variable magnetospheric rotation rate, Stallard, T., Moore, L., Melin, H., Smith, C., Agiwal, O., Chowdhury, M., Johnson, R., Knowles, K., Thomas, E., Tiranti, P., O'Donoghue, J., Mohamed, K., Muller-Wodarg, I., Coxon, J., Badman, S., Caggiano, J. 12 Mar 2026, In: Journal of Geophysical Research: Space Physics
• Photochemistry in Jupiter’s Ionosphere: Insights from Simultaneous H₃⁺ and Electron Density Observations during Juno Perijove 54, Moore, L., Melin, H., Stallard, T., O’Donoghue, J., Roberts, K., Tiranti, P., Mohamed, K., Agiwal, O., Müller-Wodarg, I., Knowles, K., Withers, P., Coffin, D., Wang, R., Schmidt, C. 30 Jan 2026, In: Planetary Science Journal
• Short-Term Variability of Jupiter's Satellite Footprints as Spotted by JWST, Johnson, R., Stallard, T., Schmidt, C., Thomas, E., Knowles, K., Tiranti, P., O'Donoghue, J., Moore, L., Melin, H., Roberts, K., Szalay, J. 16 Mar 2026, In: Geophysical Research Letters
• Auroral and Non‐Auroral H3+ Ion Winds at Uranus With Keck‐NIRSPEC and IRTF‐iSHELL, Thomas, E., Stallard, T., Melin, H., Chowdhury, M., Moore, L., O'Donoghue, J., Johnson, R., Wang, R., Knowles, K., Tiranti, P., Dello Russo, N., Vervack, R., Kawakita, H. 16 Apr 2025, In: Geophysical Research Letters
• Correction: O’Donoghue, J.; Stallard, T. What the Upper Atmospheres of Giant Planets Reveal. Remote Sens. 2022, 14, 6326, O’Donoghue, J., Stallard, T. 1 Sep 2025, In: Remote Sensing
• Discovery of H+3 and infrared aurorae at Neptune with JWST, Melin, H., Moore, L., Fletcher, L., Hammel, H., O'Donoghue, J., Stallard, T., Milam, S., Roman, M., King, O., Rowe-Gurney, N., Thomas, E., Wang, R., Tiranti, P., Harkett, J., Knowles, K. 1 May 2025, In: Nature Astronomy
• Dominant Drivers of Jupiter's H3+ Northern Aurora:1. Magnetic Field Strength and Planetary Local Time, Stallard, T., Knowles, K., Melin, H., Wang, R., Thomas, E., Moore, L., O'Donoghue, J., Johnson, R., Miller, S., Coxon, J. 19 Aug 2025, In: Journal of Geophysical Research: Space Physics
• Dominant trends in Jupiter's H3+ northern aurora: II. Magnetospheric mapping, Stallard, T., Knowles, K., Melin, H., Wang, R., Thomas, E., Moore, L., O'Donoghue, J., Johnson, R., Miller, S., Coxon, J. 1 Oct 2025, In: Journal of Geophysical Research: Space Physics

• Naoise Creery Jupiter’s fiery aurora – how heat is driven into the atmosphere Start Date: 01/10/2025 End Date: 17/10/2025
• Katie Knowles Traces of Magnetic Field in Jupiter's Equatorial Ionosphere Start Date: 01/10/2022 End Date: 17/10/2025

• PhD July 31 2001
• Senior Fellow of the Higher Education Academy SFHEA
• UKCGE recognised research supervisor