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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

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; $Δ^9$-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~$μ$m is detected at 9.2$σ$ significance, while CBD absorption at 3.69~$μ$m reaches 7.8$σ$. We additionally report a mysterious feature at exactly 4.20~$μ$m detected at 4.20$σ$ (the probability of this coincidence is discussed extensively). Our atmospheric retrievals using the novel \texttt{TerpeneRetrieval} code indicate a CBD-to-THC ratio of 0.40$\pm$0.08, classifying K2-18b as a ``balanced hybrid'' world according to standard terrestrial cannabis taxonomy. We introduce the Cannabis Habitable Zone (``Green Zone'') framework and demonstrate that K2-18b lies squarely within it. We explore multiple production mechanisms including biogenic synthesis, abiotic photochemistry, exogenous delivery via ``space nuggets,'' and deliberate atmospheric engineering by an advanced civilization. These findings suggest that K2-18b may host conditions suitable for advanced photochemistry, atmospheric relaxation processes, and possibly the most chill civilization in the galaxy. If confirmed by independent observations, this represents a paradigm shift in our understanding of biosignatures and the prevalence of recreational organic chemistry in the cosmos.

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

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; -CHO) and cannabidiol (CBD; CHO) in the transmission spectrum of the temperate sub-Neptune K2-18b. The THC feature at 2.42~m is detected at 9.2 significance, while CBD absorption at 3.69~m reaches 7.8. We additionally report a mysterious feature at exactly 4.20~m detected at 4.20 (the probability of this coincidence is discussed extensively). Our atmospheric retrievals using the novel \texttt{TerpeneRetrieval} code indicate a CBD-to-THC ratio of 0.400.08, classifying K2-18b as a ``balanced hybrid'' world according to standard terrestrial cannabis taxonomy. We introduce the Cannabis Habitable Zone (``Green Zone'') framework and demonstrate that K2-18b lies squarely within it. We explore multiple production mechanisms including biogenic synthesis, abiotic photochemistry, exogenous delivery via ``space nuggets,'' and deliberate atmospheric engineering by an advanced civilization. These findings suggest that K2-18b may host conditions suitable for advanced photochemistry, atmospheric relaxation processes, and possibly the most chill civilization in the galaxy. If confirmed by independent observations, this represents a paradigm shift in our understanding of biosignatures and the prevalence of recreational organic chemistry in the cosmos.

Paper Structure

This paper contains 36 sections, 4 equations, 9 figures.

Table of Contents

  1. Introduction
  2. A Brief History of Biosignature Science
  3. Why Cannabinoids?
  4. Target Selection: Why K2-18b?
  5. Physical Properties
  6. Optimal Temperature Regime
  7. The Presence of Liquid Water
  8. The M-Dwarf Advantage
  9. The K2 Coincidence
  10. Observations and Data Reduction
  11. JWST Program Details
  12. Data Reduction Pipeline
  13. Analysis and Results
  14. Transmission Spectrum
  15. The 4.20 $\mu$m Coincidence
  16. ...and 21 more sections

Figures (9)

  • Figure 1: Transmission spectrum of K2-18b from 0.8 to 5.5 $\mu$m showing the first detection of exoplanetary cannabinoids. The THC band at 2.42 $\mu$m is detected at 9.2$\sigma$ significance, while CBD at 3.69 $\mu$m reaches 7.8$\sigma$. Note the highly suspicious feature at exactly 4.20 $\mu$m detected at exactly 4.20$\sigma$. The probability of this numerical coincidence is discussed in Section \ref{['subsec:coincidence']}.
  • Figure 2: Posterior distributions from our atmospheric retrieval using TerpeneRetrieval v4.20. The THC and CBD abundances show strong positive correlation (Pearson $\rho = 0.63$), suggesting a common production mechanism. The Bayes factor comparing the cannabinoid model to a cannabinoid-free model is $\mathcal{B} = 10^{420}$, which we acknowledge is suspiciously convenient.
  • Figure 3: Spatially-resolved cannabinoid distribution on K2-18b derived from phase-curve observations. Left: THC volume mixing ratio, showing enhancement on the day side. Center: CBD volume mixing ratio, with peaks near the terminators. Right: CBD/THC ratio map revealing the "Optimal Relaxation Zone" on the night side where CBD dominates.
  • Figure 4: Detection significance ($\sigma$) for molecular species in K2-18b's atmosphere. The horizontal dashed lines indicate the 3$\sigma$ and 5$\sigma$ detection thresholds. THC and CBD exceed the canonical 5$\sigma$ discovery threshold, while DMS remains marginal. CBN and terpenes show tentative detections warranting future investigation.
  • Figure 5: Temporal variability in K2-18b's cannabinoid abundances over five orbital periods. Top: Transit depth variations indicating changing atmospheric opacity ("haze"). Middle: THC volume mixing ratio showing periodic enhancement during "Peak Season." Bottom: CBD mixing ratio and CBD/THC ratio variations.
  • ...and 4 more figures