Nearly 1.5 million kilometers away at the Sun-Earth Lagrange Point 2 (L2), the James Webb Space Telescope’s observation point today offers us a unique perspective of our neighboring red planet, Mars. The giant telescope gives scientists and the public a glimpse of the observable disk of Mars, that is, the part of the sunlit side of the planet that faces Mars.
The first images of Mars from this fantastic telescope were captured by its near-infrared camera (NIRCam). They represent a region of the planet’s eastern hemisphere in two different wavelengths, or colors, of infrared light. This includes a look at Hellas Basin , one of the largest known impact craters in the solar system that is around 7,152 meters deep.
Mars is one of the brightest objects in the night sky
Because Mars is relatively close (to us) and very bright, it is not the easiest object to view for the JWST, designed to see incredibly distant and faint objects but, to prevent the bright light from Mars from blinding the JWST’s instruments. Webb, the researchers used very short exposures to observe the red planet. This meant measuring only part of the light reaching JWST’s detectors , and then applying special methods to analyze the data collected by the MOLA instrument.
It consists largely of reflected sunlight, so it appears very similar to visible-light images. As the light emitted by the planet passes through the Martian atmosphere, some of it is absorbed by carbon dioxide (CO2) molecules, making the Hellas Basin appear darker than the surrounding area due to this effect.
NASA explained the telescope’s outlook in a statement: “Webb can capture images and spectra with the spectral resolution necessary to study short-term phenomena such as dust storms, weather patterns, seasonal changes, and, in a single observation, processes that occur in different times ” (day, sunset and night) of a Martian day.
James Webb is “behind” our planet as seen from the Sun and, since its launch, we have already been able to see impressive nebulae or spectacular galaxy clusters, as well as other members of our solar system that have already been immortalized by the telescope. Just last month, Webb’s first images of Jupiter were released, revealing the planet’s rings, some of its moons, and even auroras.
Referencia: Mars is mighty in first Webb observations of Red Planet
NASA – ESA James Webb Space Telescope Press Release