Let’s look at a world 635 lightyears away that just might have a fiery moon of volcanic goodness. To be honest, every aspect of this system is hot. The star is similar our Sun, but the planet is on an 2.8 day orbit around that star, and this orbit makes Mercury look super distant from the Sun. From our perspective here on Earth, this world, WASP-49 A, passes in front of its star, allowing us to see it’s size and the chemical make up of its atmosphere. Observations show the planet to be an extremely overheated and a sibling to Saturn.
Credit: NASA Jet Propulsion Laboratory
While observing this world, astronomers discovered a cloud of sodium displaced from the planet’s location. This cloud appears to be in motion and, per the paper, can’t be “readily explained by stellar activity, starspots, tellurics, or the interstellar medium”. When all mundane reasons can be ruled out, it’s time to look for extraordinary explanations. In this case, the observed gas is consistent with this hot Saturn being orbited by a volcanically active rocky moon. Now, as Carl Sagan has said, extraordinary claims require extraordinary evidence, and a lot more data is needed before we can say this is absolutely what’s happening. For now, though, this is a cool possibility that totally fits the data, and I, for one, wish this team all the telescope time they might need to prove this super cool result.
References:
- Possible Volcanic Moon Detected 635 Light-Years Away (JPL Website)
- Oza, A. V., Seidel, J. V., Hoeijmakers, H. J., Unni, A., Kesseli, A. Y., Schmidt, C. A., … & Johnson, R. E. (2024). Redshifted sodium transient near exoplanet transit. The Astrophysical Journal Letters, 973(2), L53. http://doi.org/10.3847/2041-8213/ad6b29