Science & Technology

James Webb gets a close look at the Red Planet for the first time

Perseverance rover collects key rock samples, while Mars shows signatures of water, carbon dioxide in atmosphere 

By Nandita Banerji
Published: Tuesday 20 September 2022
A close up of Mars’ surface features on the left, while a ‘heat map’ on the right shows light being given off as the planet loses heat. Photo: @NASAWebb / Twitter
A close up of Mars’ surface features on the left, while a ‘heat map’ on the right shows light being given off as the planet loses heat. Photo: @NASAWebb / Twitter A close up of Mars’ surface features on the left, while a ‘heat map’ on the right shows light being given off as the planet loses heat. Photo: @NASAWebb / Twitter

The National Aeronautics and Space Administration is closer to unfolding more Mars secrets with the help of both the James Webb Space Telescope (JWST) and the rover, Perseverance. 

JSWT captured its first images and infrared spectrum of the red planet September 5, 2022. The spectrum has the signatures of water, carbon dioxide and carbon monoxide in Mars’ atmosphere. 

The telescope showed a region of the planet’s eastern hemisphere at two different wavelengths or colours of infrared light. A close up of the surface area revealed the rings of Huygens Crater, dark volcanic rock of Syrtis Major and brightening in the Hellas Basin. 

The images provide a unique perspective with its infrared sensitivity on our neighbouring planet, complementing data being collected by orbiters, rovers and other telescopes.

Read more: Martian surprise: NASA’s Perseverance finds igneous rocks altered by water

Meanwhile, NASA’s Perseverance rover has collected several samples of rocks. The rover is digging into an area called Jezero Crater that scientists consider a top prospect for finding signs of ancient microbial life on Mars.  

The rover has collected four samples from an ancient river delta in the Red Planet’s Jezero Crater since July 7, bringing the total count of scientifically compelling rock samples to 12.

The space agency plans to retrieve the rock samples through another programme by 2033. These first collected and returned samples could answer a key question: did life ever exist on Mars? 

“Percy”, as the rover is fondly called, is searching for the traces of biological life that could have existed 3.5 billion years ago when Jezero was filled with a lake and a river. 

JWST, which NASA claims is the world’s most powerful, was launched December 25, 2022, in collaboration with European Space Agency and Canadian Space Agency. It orbits around the Sun, unlike the Hubble telescope that orbits around Earth. 

The images look different compared to the ones captured before. This is because Webb was built to detect faint light from distant galaxies. However, Mars is extremely bright. 

NASA used special techniques and very short exposures to avoid Webb being flooded with light while capturing these images.

Preliminary spectrum analysis showed 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.

Webb’s first near-infrared spectrum of Mars. Source: NASA 

Read more: Oxygen on Mars? Lunchbox-sized gadget makes it possible

The researchers have been analysing the spectral data from these observations and are preparing a paper they will submit to a scientific journal for peer review and publication.

In the future, the Mars team will be using this imaging and spectroscopic data to explore regional differences across the planet and to search for trace gases in the atmosphere, including methane and hydrogen chloride.

JSWT primarily observes infrared light, which can sometimes be felt as heat. Because the telescope will be observing the very faint infrared signals of very distant objects, it needs to be shielded from any bright, hot sources.

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’.

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