OTES, the OSIRIS-REx Thermal Emission Spectrometer, captured these infrared spectral curves during Earth Gravity Assist on Sept. 22 2017, hours after the spacecraft’s closest approach. The peaks and valleys in the curves are known as absorption features and show differences in absorption of the sun’s energy due to different substances (water vapor, carbon dioxide, methane and ozone) in Earth’s atmosphere. The curves also provide temperature information for different heights in the atmosphere. The smooth red and blue curves show the temperatures of the ocean surface and the stratosphere without the effects of the absorption features. OTES was built and is operated by Arizona State University in Tempe, Ariz. Inset: An image of Earth captured by the OSIRIS-REx Camera Suite (OCAMS) on the same date shows the approximate locations and sizes of the “spots” (each 800 kilometers in diameter) on the Earth that were scanned by the OTES instrument to produce these spectral curves. Credit: NASA/Goddard/University of Arizona/Arizona State University