Although the James Webb Space Telescope was built primarily for looking back at the earliest and most distant galaxies, it can also be used for a host of other scientific observations — including looking at targets right here in our own solar system. Webb will perform a major study of Jupiter and has already imaged Neptune. Now, Webb has been used to get a fascinating look at our planetary neighbor, Mars.
It’s actually pretty difficult for Webb to study Mars because it is so close, and therefore very bright in both the visible light portion of the spectrum and in the infrared wavelengths at which Webb observes. The brightness can oversaturate the detectors which are designed to pick up very faint light sources. But Webb’s NIRCam camera was able to capture the martian surface, with two images captured at different wavelengths shown below.
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Webb’s first images of Mars, captured by its NIRCam instrument Sept. 5, 2022 [Guaranteed Time Observation Program 1415]. Left: Reference map of the observed hemisphere of Mars from NASA and the Mars Orbiter Laser Altimeter (MOLA). Top right: NIRCam image showing 2.1-micron (F212 filter) reflected sunlight, revealing surface features such as craters and dust layers. Bottom right: Simultaneous NIRCam image showing ~4.3-micron (F430M filter) emitted light that reveals temperature differences with latitude and time of day, as well as darkening of the Hellas Basin caused by atmospheric effects. The bright yellow area is just at the saturation limit of the detector.NASA, ESA, CSA, STScI, Mars JWST/GTO teamThe shorter wavelength image, shown at the top, is similar to a visible light image and shows features like craters and basins. The longer wavelength image, shown below, shows how the planet is radiating heat. The brightest spot is where the sun is directly overhead, with cooler regions toward the poles. The Hellas Basin also appears darker, though this isn’t because of temperature effects but rather due to the effects of altitude and air pressure.
Webb was also able to capture Mars using its spectrometry instruments. These can split light into different wavelengths to see the composition of an object — in this case, looking at the composition of the martian atmosphere as a whole. There are clear indications of carbon dioxide, water, and carbon monoxide, and what is impressive about this is how well the data fits the model of what we already know about Mars’s atmosphere. This shows just how effective Webb’s instruments are for this kind of spectrometry work — and how effective Webb has the potential to be when looking into the atmospheres of exoplanets.
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, for example, the Planetary Spectrum Generator, abundances of given molecules in the atmosphere can be derived.NASA, ESA, CSA, STScI, Mars JWST/GTO team
The research using this Webb data is still being worked on and has not yet been published or peer-reviewed, so it shouldn’t be taken as definitive. But it goes to show just how versatile a tool Webb can be, with more Webb data on Mars still to come.
Well-known star turns out to be not one star, but twins
This artist’s concept shows two young stars nearing the end of their formation. Encircling the stars are disks of leftover gas and dust from which planets may form. Jets of gas shoot away from the stars’ north and south poles. U.S. NSF/NSF NRAO/B. Saxton
There are some regions and objects that become favorite targets for astronomers -- often because they are nearby (and so easier to observe) and because they are a well-known example of an object like a stellar nursery or a black hole. But occasionally, even these well-known objects turn out to be hiding surprises. This was the case recently, when observations from the James Webb Space Telescope revealed that a particular star, WL 20S, in the frequently observed WL20 region, turned out not to be a single star at all, but actually a pair.
Auroras and radiation from solar storms spotted on Mars
The specks in this scene were caused by charged particles from a solar storm hitting a camera aboard NASA’s Curiosity Mars rover. Curiosity uses its navigation cameras to try and capture images of dust devils and wind gusts, like the one seen here. NASA/JPL-Caltech
The recent solar storms caused epic events here on Earth, where auroras were visible across much of the globe last month. These storms, caused by heightened activity from the sun, don't only affect our planet though -- they also affect Mars. NASA missions like the Curiosity rover have been observing the effects of solar storms there, where the very thin atmosphere creates a potentially dangerous radiation environment. If we ever want to send people to visit the red planet, we're going to need to learn more about this radiation and how it's affected by events like solar storms.
Fly over the trenches of Mars in stunning video of Nili Fossae
A video simulates a flyover of the Nili Fossae trenches on Mars. CREDIT ESA/DLR/FU Berlin & NASA/JPL-Caltech/MSSS ACKNOWLEDGEMENTS Data: ESA/DLR/FU Berlin/NASA/MSSS ; Data processing and animation: Björn Schreiner, Greg Michael, Image Processing Group (FU Berlin) ; Music: Björn Schreiner ; Created by Freie Universität Berlin Planetary Sciences and Remote Sensing 2024 (CC BY-SA 3.0 IGO)
A new video from the European Space Agency (ESA) shows a stunning flyover of Mars's Nili Fossae trenches that was constructed using data from the Mars Express mission. The dramatic landscapes of Mars include huge mountains like Olympus Mons, the largest mountain in the solar system, and deep canyons.
