I freely admit that my mind is blown any time anyone presents any data that shows anything definite about the atmospheres of exoplanets. I (wrongly) predicted that we would not see this in my lifetime, and I could not be more delighted to be wrong.
The first JWST exoplanet spectrum came in the original release of five images, and identified water in the atmosphere of WASP-96 b. This is a hot gas giant orbiting a Sun-like star more than 1,000 ly away. The spectrum is a transmission spectrum: the planet was observed as it transited the star, and then the spectrum was compared to that of the star when the planet is not in view. The spectrum has a wide range of wavelengths, and multiple water lines are present across the full spectrum. I see other narrower lines there as well that I’m certain are being investigated further.
But already, we have more! In August, a similar transmission spectrum for WASP-39 b was released, (https://www.nasa.gov/feature/goddard/2022/nasa-s-webb-detects-carbon-dioxide-in-exoplanet-atmosphere) showing a clear detection of carbon dioxide in the atmosphere of that hot gas giant.
All that said, it’s a bit of a heavy lift to help students understand how exciting a graph can be! They’ll need you to help them understand why they should be astonished that we can determine the composition of the atmosphere of a planet (even a Jupiter-sized one) from 1,000 light years away.
Supporting material in the texts and online: This image ties in to a deep fascination about life in the universe---if we are all honest about it, we are anxiously awaiting the first detection of O2. You might reference this image in the chapters on the Formation of Stars and Planets, the Giant Planets, Exoplanets or Life in the Universe.
Exploration: Exploring Exoplanets
Process of Science Assignment: Light and Spectroscopy
Interactive Simulations: Planetary Orbits Simulator and Habitable Zone
Astrotours: Atmospheres: Formation and Escape
Astronomy in Action videos: Emission and Absorption
Learning Astronomy by Doing Astronomy Workbook, Activity 6: Extraterrestrial Tourism explores the relationship between observations and properties of planets; Activity 35: Finding Habitable Worlds beyond Earth will help students understand why we are interested in the orbital properties of planets.