File:Mars Is Mighty in First Webb Observations of Red Planet - 52368008867.png

English: This spectrum, its first of Mars, combines data measured by Webb’s NIRSpec instrument, and shows the signatures of water, carbon dioxide and carbon monoxide in Mars’ atmosphere! The data also gives us information about the planet’s dust, clouds, rocks and more. Spectra like this one are created when light is split apart into its components.

Read more: blogs.nasa.gov/webb/2022/09/19/mars-is-mighty-in-first-we...

More detail:

Webb’s first near-infrared spectrum of Mars, captured by the Near-Infrared Spectrograph (NIRSpec) Sept. 5, 2022, as part of the Guaranteed Time Observation Program 1415, over 3 slit gratings (G140H, G235H, G395H). The spectrum is dominated by reflected sunlight at wavelengths shorter than 3 microns and thermal emission at longer wavelengths. Preliminary analysis reveals the spectral dips appear at specific wavelengths where light is absorbed by molecules in Mars’ atmosphere, specifically carbon dioxide, carbon monoxide, and water. Other details reveal information about dust, clouds, and surface features. By constructing a best-fit model of the spectrum, by the using, for example, the Planetary Spectrum Generator, abundances of given molecules in the atmosphere can be derived.

Credit: NASA, ESA, CSA, STScI, Mars JWST/GTO team

Image description: mage Description: Graph titled “Mars Atmosphere Composition,” showing data from Webb’s NIRSpec instrument, Fixed Slit Spectroscopy mode. The x-axis is “Wavelength of Light” in microns, ranging from 1.0 to 5.0. The y-axis shows “Brightness of Light (reflected and emitted),” and from bottom to top it goes from dimmer to brighter. Data is represented by a white line with dynamic peaks and dips, both big and small. A purple best-fit line is overlaid on top of the white line. In general, the line starts high, dips (with especially low valleys around 2.75 microns and 4.3-4.4 microns), then rises back up starting around 4.5 microns. Several signatures of molecules can be found in the data, including 5 instances of carbon dioxide (highlighted as yellow vertical stripes on the chart), 1 instance of carbon monoxide (highlighted as a thick red stripe beyond 4.5 microns), and 1 instance of water (highlighted as a thin blue stripe beyond 2.5 microns). The background is a Mars “heat map” taken by Webb’s NIRCam.