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.
James Webb is explaining the puzzle of some of the earliest galaxies
From practically the moment it was turned on, the James Webb Space Telescope has been shaking cosmology. In some of its very earliest observations, the telescope was able to look back at some of the earliest galaxies ever observed, and it found something odd: These galaxies were much brighter than anyone had predicted. Even when the telescope's instruments were carefully calibrated over the few weeks after beginning operations, the discrepancy remained. It seemed like the early universe was a much busier, brighter place than expected, and no one knew why.
This wasn't a minor issue. The fact early galaxies appeared to be bigger or brighter than model predicted meant that something was off about the way we understood the early universe. The findings were even considered "universe breaking." Now, though, new research suggests that the universe isn't broken -- it's just that there were early black holes playing tricks.
Mars has ‘oceans’ worth’ of water – but it’s deep underground
One of the key issues for getting humans to Mars is finding a way to get them water. Scientists know that millions of years ago, Mars was covered in oceans, but the planet lost its water over time and now has virtually no liquid water on its surface. Now, though, researchers have identified what they believe could be oceans' worth of water on Mars. There's just one snag: it's deep underground.
The research used data from NASA's now-retired InSight lander, which used a seismometer and other instruments to investigate the planet's interior. They found evidence of what appears to be a large underground reservoir of water, enough to cover the entire planet in about a mile of ocean. But it's inaccessible, being located between 7 to 13 miles beneath the planet's surface. The water is located in between cracks in a portion of the interior called the mid-crust, which sits beneath the dry upper crust that is drillable from the surface.
James Webb Telescope captures gorgeous galaxy with a hungry monster at its heart
A new image from the James Webb Space Telescope shows off a nearby galaxy called Messier 106 -- a spiral galaxy that is particularly bright. At just 23 million light-years away (that's relatively close by galactic standards), this galaxy is of particular interest to astronomers due to its bustling central region, called an active galactic nucleus.
The high level of activity in this central region is thought to be due to the monster that lurks at the galaxy's heart. Like most galaxies including our own, Messier 106 has an enormous black hole called a supermassive black hole at its center. However, the supermassive black hole in Messier 106 is particularly active, gobbling up material like dust and gas from the surrounding area. In fact, this black hole eats so much matter that as it spins, it warps the disk of gas around it, which creates streamers of gas flying out from this central region.
