While the calibration of its scientific instruments is coming to an end, the teams of the james webb telescope also train to maneuver it, and to follow the slow ballet of the objects of our Solar System. Because if it is equipped to see far, the telescope will be regularly rotated in our vicinity…
On the menu, asteroids, comets and frozen moons!
Far vision, near vision
Since the optical alignment of mirrors and instruments has been completed, the James Webb telescope, 1.5 million kilometers from Earth, only has a few steps left to validate before starting its long scientific career. These last weeks of preparation have been dedicated to testing and calibrating the 17 operating modes, involving its four instruments NIRCam, NIRSpec, NIRISS and MIRI, and so far all the feedback is very positive. It seems that after a very long wait, the performance will be even better than expected! The JWST also performed its first dynamic tracking tests, during which it points to an object in the Solar System, pivoting on itself to follow it in its relative motion. An essential capability for observing nearby events, but also a delicate exercise, because the telescope’s maneuvering capabilities are limited: it must remain in the shade of its gigantic sun visor.
A matter of pioneers
For the first medium-term tracking goal, the teams chose asteroid 6481 Tenzing, located in the asteroid belt between Mars and Jupiter. By the scientists’ own admission, you might as well choose a target that represents a pioneering success: this large space rock is named after Sherpa Tenzing Norgay, who in 1953 accompanied mountaineer Edmund Hillary to conquer Everest. However, it is only a question of “following” the asteroid, not of studying it in detail… Unlike the future targets of the JWST.
If it will be a pioneer in seeing far, studying galaxies and distant star clusters, the telescope will indeed regularly be pointed much closer to us. Scientific teams rely in particular on its spectroscopic capabilities to study the composition of the geysers of frozen moons, in particular Enceladus (around Saturn).
Close discoveries on the way!
Like Hubble before it (although with additional usage limitations), the James Webb telescope will be called upon to observe asteroids, in particular those which will be the subject of dedicated missions, but also comets, because its equipment will make it possible to learn more about the composition of the ejected gases. It will also be turned, quite simply, towards the planets Uranus and Neptune, very little visited but for which the scientific community awaits new discoveries. And that’s not counting the hunt for the hypothetical “planet 9”, the observation of dwarf planets like Pluto or Eris, and the search for new small bodies in the Kuiper belt.
Heidi Hammel, JWST manager for Solar System observations, recalls that the asteroid Arrokoth was discovered by Hubble as part of a dedicated campaign, which then allowed its flyby by the New Horizons mission in 2019. One thing is sure, as soon as it is launched, the James Webb’s program will be incredibly busy!
Source : NASA
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