Webb takes its first infrared image of Mars
Click for full image.
Astronomers have now released the the James Webb Space Telescope’s first infrared image of Mars, taken on September 5, 2022.
The image to the right, cropped and reduced to post here, shows some of the data obtained. Because Mars is so close, it is actually too bright for Webb’s instruments. To get any data, the exposures were very very short, and still the brightest areas — as indicated by large areas of yellow — are overexposed. The cause of the different brightness of Hellas Basin, however, is not simply because the basin — the deepest point on Mars — is cooler.
As light emitted by the planet passes through Mars’ atmosphere, some gets absorbed by carbon dioxide (CO2) molecules. The Hellas Basin – which is the largest well-preserved impact structure on Mars, spanning more than 1,200 miles (2,000 kilometers) – appears darker than the surroundings because of this effect. “This is actually not a thermal effect at Hellas,” explained the principal investigator, Geronimo Villanueva of NASA’s Goddard Space Flight Center, who designed these Webb observations. “The Hellas Basin is a lower altitude, and thus experiences higher air pressure. That higher pressure leads to a suppression of the thermal emission at this particular wavelength range [4.1-4.4 microns] due to an effect called pressure broadening. It will be very interesting to tease apart these competing effects in these data.”
The NASA press release says the scientists are preparing a paper analyzing the spectral data and what it revealed about “dust, icy clouds, what kind of rocks are on the planet’s surface, and the composition of the atmosphere,” I suspect however that Webb’s capabilities for studying Mars are much more limited than implied, and that it will over time take much fewer images of the red planet, compared to Hubble.
Readers!
Every February I run a fund-raising drive during my birthday month. This year I celebrate my 72nd birthday, and hope and plan to continue writing and posting on Behind the Black for as long as I am able.
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Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
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Click for full image.
Astronomers have now released the the James Webb Space Telescope’s first infrared image of Mars, taken on September 5, 2022.
The image to the right, cropped and reduced to post here, shows some of the data obtained. Because Mars is so close, it is actually too bright for Webb’s instruments. To get any data, the exposures were very very short, and still the brightest areas — as indicated by large areas of yellow — are overexposed. The cause of the different brightness of Hellas Basin, however, is not simply because the basin — the deepest point on Mars — is cooler.
As light emitted by the planet passes through Mars’ atmosphere, some gets absorbed by carbon dioxide (CO2) molecules. The Hellas Basin – which is the largest well-preserved impact structure on Mars, spanning more than 1,200 miles (2,000 kilometers) – appears darker than the surroundings because of this effect. “This is actually not a thermal effect at Hellas,” explained the principal investigator, Geronimo Villanueva of NASA’s Goddard Space Flight Center, who designed these Webb observations. “The Hellas Basin is a lower altitude, and thus experiences higher air pressure. That higher pressure leads to a suppression of the thermal emission at this particular wavelength range [4.1-4.4 microns] due to an effect called pressure broadening. It will be very interesting to tease apart these competing effects in these data.”
The NASA press release says the scientists are preparing a paper analyzing the spectral data and what it revealed about “dust, icy clouds, what kind of rocks are on the planet’s surface, and the composition of the atmosphere,” I suspect however that Webb’s capabilities for studying Mars are much more limited than implied, and that it will over time take much fewer images of the red planet, compared to Hubble.
Readers!
Every February I run a fund-raising drive during my birthday month. This year I celebrate my 72nd birthday, and hope and plan to continue writing and posting on Behind the Black for as long as I am able.
I hope my readers will support this effort. As I did in my November fund-raising drive, I am offering autographed copies of my books for large donations. Donate $250 and you can have a choice of the hardback of either Genesis: the Story of Apollo 8 or Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space. Donate $200 and you can get an autographed paperback copy of either. IMPORTANT! If you donate enough to get a book, please email me separately to tell me which book you want and the address to mail it to.
Please consider supporting my work here at Behind the Black. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Every one of those 2020 conclusions has turned out right.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
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