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.
Webb captures a Penguin and an Egg for its two-year anniversary
This “penguin party” is loud! The distorted spiral galaxy at center, called the Penguin, and the compact elliptical galaxy at left, called the Egg, are locked in an active embrace. A new near- and mid-infrared image from the James Webb Space Telescope, taken to mark its second year of science, shows that their interaction is marked by a faint upside-down U-shaped blue glow. NASA, ESA, CSA, STScI
Today, July 12, marks two years since the first images from the James Webb Space Telescope were unveiled. In that time, Webb has discovered the most distant galaxies known, uncovered surprises about the early universe, peered into the atmospheres of distant planets, and produced a plethora of beautiful images of space.
James Webb snaps a colorful image of a star in the process of forming
L1527, shown in this image from NASA’s James Webb Space Telescope’s MIRI (Mid-Infrared Instrument), is a molecular cloud that harbors a protostar. It resides about 460 light-years from Earth in the constellation Taurus. NASA, ESA, CSA, STScI
A stunning new image from the James Webb Space Telescope shows a young star called a protostar and the huge outflows of dust and gas that are thrown out as it consumes material from its surrounding cloud. This object has now been observed using two of Webb's instruments: a previous version that was taken in the near-infrared with Webb's NIRCam camera, and new data in the mid-infrared taken with Webb's MIRI instrument.
See a stunning 3D visualization of astronomy’s most beautiful object
This image is a mosaic of visible-light and infrared-light views of the same frame from the Pillars of Creation visualization. The three-dimensional model of the pillars created for the visualization sequence is alternately shown in the Hubble Space Telescope version (visible light) and the Webb Space Telescope version (infrared light). Greg Bacon (STScI), Ralf Crawford (STScI), Joseph DePasquale (STScI), Leah Hustak (STScI), Christian Nieves (STScI), Joseph Olmsted (STScI), Alyssa Pagan (STScI), Frank Summers (STScI), NASA's Universe of Learning
The Pillars of Creation are perhaps the most famous object in all of astronomy. Part of the Eagle Nebula, this vista was first captured by the Hubble Space Telescope in 1995, and has captivated the public ever since with its dramatic rising pillars of dust and gas that stretch several light-years high. The nebula has been imaged often since then, including again by Hubble in 2014 and more recently by the James Webb Space Telescope in 2022.
