space First Ever

Astronomers have detected the chemical signatures of THC and CBD in the atmosphere of a distant 'sub-Neptune' planet.

April 1, 2026

Original Paper

First Detection of Exoplanetary Cannabinoids: Evidence for THC and CBD in the Atmosphere of K2-18b

Amie J. Chism, Mary Jane van der Pot, Blaise P. Hasheau, Hans-Joachim Grasmann, Bonnie McToke, Bud Wellington-Kush, Maria Hierba-Verde, Puff D. Magic

arXiv · 2603.29700

The Takeaway

Finding the building blocks of life on other planets is the ultimate goal of the James Webb Space Telescope, but finding the active compounds in cannabis is a total surprise. The researchers identify these 'cannabinoids' with high statistical significance, jokingly suggesting the planet might be the most 'chill' civilization in the galaxy.

From the abstract

We report the first unambiguous detection of cannabinoid molecules in an exoplanetary atmosphere. Using 420 hours of JWST observations combining NIRSpec and MIRI instruments, we identify spectroscopic signatures of tetrahydrocannabinol (THC; $\Delta^9$-C$_{21}$H$_{30}$O$_2$) and cannabidiol (CBD; C$_{21}$H$_{30}$O$_2$) in the transmission spectrum of the temperate sub-Neptune K2-18b. The THC feature at 2.42~$\mu$m is detected at 9.2$\sigma$ significance, while CBD absorption at 3.69~$\mu$m reach