Starts With A Bang podcast #116 – Disintegrating exoplanets
- Out there in the Universe, exoplanets orbit their parent stars at all distances, with all masses, and at all temperatures: even super-close to their parent stars and with super-hot temperatures.
- Under extreme enough conditions, exoplanets can evaporate or, for completely atmosphere-free worlds, even have their crusts, mantles, and cores disintegrate.
- It was almost 15 years ago that we found our first candidate disintegrating, rocky exoplanet, but the story has changed dramatically in recent years. Here’s how we’ve caught our most compelling one yet right in the act!
Out there in the Universe, each star represents an opportunity: a chance for a stellar system to develop that just might possess something remarkable. While we normally think about life, and intelligent life at that, as the grand prize the Universe has to offer, there are a wide variety of fascinating phenomena that are out there to consider. Whereas Mercury, for example, is the closest world to our Sun in our own Solar System, it still takes 88 days to make a complete revolution. In other systems, however, exoplanets can be so hot that they orbit their parent star in less than a single Earth day.
In fact, we’ve discovered a few systems that are so extreme, the planets that orbit them are in the process of disintegrating: where the heat, winds, and radiation from the parent star actually blows part of the planet itself away. This doesn’t just include a planet’s atmosphere, which is what we see for giant worlds, but even the surfaces and interiors of rocky planets in the most extreme cases. At temperatures of around 2000 degrees and upwards, these exoplanets can lose their crusts, mantles, and even their cores over long enough timescales.
Believe it or not, we’ve actually caught a few exoplanets doing exactly this, and we’ve got the JWST spectra in hand for one of them now, teaching us, for the first time, what a planetary interior is made of outside of our own Solar System. I’m so pleased to have the first author from that 2025 study, soon-to-be Dr. Nick Tusay, as our guest on this edition of the Starts With A Bang podcast, as we take a look at the most extreme exoplanetary systems ever discovered!
