ALT A graphic titled “Exoplanet K2-18 b: Atmosphere Composition.” The graphic shows the spectra of the exoplanet K2-18 b from NIRISS and NIRSpec in the form of a graph, with the vertical y-axis labeled as Amount of Light Blocked and the horizontal axis labeled as Wavelength of Light (microns). The data is plotted as dots with vertical error bars. A jagged blue line running through the plot represents the best-fit model. There are semi-transparent magenta, red and green vertical columns also scattered across the plot, indicating where variations in the line represent the presence of methane, carbon dioxide, and dimethyl sulfide (combined with other molecules), respectively. Behind the graph is an illustration of the planet and star. The planet is a large fuzzy blue-ish sphere off to the right, taking up half of the background. The red star is smaller at the bottom left of the entire graphic.
