Episode Details

The last time a spacecraft visited Uranus or Neptune, it was 1986 and 1989 respectively, and nobody has been back since. This episode explores why these two outer worlds get lumped in together as "ice giants" rather than gas giants, Uranus's bizarre sideways tilt, Neptune's discovery through pure mathematics before anyone had even seen it through a telescope, supersonic winds, oddly lopsided magnetic fields, and the genuinely uncertain science of whether it might rain diamonds deep inside these planets.

You'll come away understanding what actually separates an ice giant from a gas giant, why Uranus spins on its side and what that does to its seasons, how astronomers predicted Neptune's existence before finding it, why these two planets have the fastest winds and strangest magnetic fields in the solar system, why the diamond rain idea is a laboratory-based model rather than a direct observation, and why scientists are pushing hard for a dedicated return mission.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: NASA – Uranus and Neptune fact sheets and Voyager 2 mission archives; ESA – outer planets science pages; National Academies of Sciences – Planetary Science and Astrobiology Decadal Survey 2023–2032; Nature Astronomy – reporting on ice giant interior modelling.