The Webb Space Telescope is going through a final “configuration” phase, after which all scientific instruments will be able to take images and spectra as directed. However, we already know that what he will achieve this year and the coming years will be a huge success
“Don’t say jump until you jump,” but there is no indication that the Webb Space Telescope’s delivery phase will be a problem. This is why NASA and the European Space Agency are already bragging about comparative images that show how good a picture the new telescope will provide compared to the previous one. And it’s not just about the sharpness of the image that each monitoring tool offers.
Which telescope is better compared to Webb for infrared observation?
Webb is best compared to telescopes like Spitzer, especially in the mid-infrared range, as in both cases they observed electromagnetic radiation at the same wavelength. The attached tweet, which has been circulating on the web for several days, also includes an image from the WISE telescope, which has been orbiting the Earth since 2010. Spitzer was launched in 2003, and recently completed, in January 2020.
Spitzer observed an example of a portion of the sky with the IRAC camera at 7.7 micrometers long, and Webb’s MIRI instrument will look at space at 8 micrometers. The two telescopes differ in many ways. Below is a comparative table in the case of the above mentioned monitoring tools.
|Workplace||revolve around the sun
The telescope is moving behind the earth
|around point L2
About 1.5 million km from Earth
|Main mirror size||0.85 m||6.5 m|
|infrared monitoring range||3.6 to 8 µm
|4.9 to 29.8 µm
|field of view||5.2 x 5.2 arc minutes||1.9 x 1.2 arc minutes|
(single sensor resolution)
|256 x 256 pixels||1024 x 1024 pixels|
|spatial accuracy||2 arc seconds||0.11 arc second|
As you can see, Webb will achieve not only high image resolution, but also image detail, the spatial resolution of which will be about twenty times greater than that of Spitzer.
Changing image details feels like changing from HD to 8K
The illustrations, showing parts of the Large Magellanic Cloud, show a massive increase in detail. Spitzer took his photos in his heyday, which was in the years before 2009 (before he ran out of coolant). The era of the Web is yet to come.
Items that Spitzer can see are displayed more accurately, but additional noise also emerges from background noise. Yes, with today’s advanced image processing technologies, even in fuzzy images, it is possible to detect seemingly invisible objects, but with great error (uncertainty). The greater the error of the measurement, the less useful these objects are in testing different theories. Webb will provide stars and nebulae that stand out more clearly from the background, and this will translate into slight errors in measuring their brightness and evaluating the shape.
The fastest MIRI tool on board Webb will age. And it’s not just about physical fatigue, it’s just about the wear and tear of an item. More precisely, the coolant that keeps MIRI cool at only 7 K. Other instruments can be operated at higher 30K, this can be achieved by passive cooling
Since the typical comparative images are already different, in favor of Webb, it is easy to imagine that every place in the sky that astronomers look at with this telescope will be visible for the first time.
Source: NASA, inf. king
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