NASA shares jaw-dropping first images of Mars captured by James Webb Space Telescope

Washington, Sep 20: NASA's James Webb Space Telescope , which was launched in December 2021, has captured its first images and spectra of Mars. Webb captured the images with its Near InfraRed Camera, or NIRCam, instrument on Sept. 5, along with data from its Near InfraRed Spectrometer (NIRSpec). The telescope, an international collaboration with ESA (European Space Agency) and CSA (Canadian Space Agency), provides a unique perspective with its infrared sensitivity on our neighboring planet, complementing data being collected by orbiters, rovers, and other telescopes.

The top right, top left, and bottom left corners of the first image each have three lighter brown patches that break up the predominantly mottled dark brown colour. The colour coding indicates that these lighter parts are brighter. Syrtis Major (black volcanic rock), Huygens Crater, and the Hellas Basin are all indicated by arrows.

Webb's unique observation post nearly a million miles away at the Sun-Earth Lagrange point provides a view of Mars' observable disk (the portion of the sunlit side that is facing the telescope). As a result, Webb can capture images and spectra with the spectral resolution needed to study short-term phenomena like dust storms, weather patterns, seasonal changes, and, in a single observation, processes that occur at different times (daytime, sunset, and nighttime) of a Martian day.

Because it is so close, the Red Planet is one of the brightest objects in the night sky in terms of both visible light (which human eyes can see) and the infrared light that Webb is designed to detect. This poses special challenges to the observatory, which was built to detect the extremely faint light of the most distant galaxies in the universe.

Webb's instruments are so sensitive that without special observing techniques, the bright infrared light from Mars is blinding, causing a phenomenon known as "detector saturation." Astronomers adjusted for Mars' extreme brightness by using very short exposures, measuring only some of the light that hit the detectors, and applying special data analysis techniques.

This infrared spectrum was obtained by combining measurements from all six of the high-resolution spectroscopy modes of Webb's Near-Infrared Spectrograph (NIRSpec). Preliminary analysis of the spectrum shows a rich set of spectral features that contain information about dust, icy clouds, what kind of rocks are on the planet's surface, and the composition of the atmosphere. The spectral signatures - including deep valleys known as absorption features - of water, carbon dioxide, and carbon monoxide are easily detected with Webb. The researchers have been analyzing the spectral data from these observations and are preparing a paper they will submit to a scientific journal for peer review and publication.