After 14 excruciating yr of delays and surviving the blank - metacarpophalangeal joint tenseness of launch and deployment , the world ’s most powerful infinite telescope faces only one remaining threat : space rocks . NASA has declare the JWST ’s primary mirror was hit by a micrometeor in May . It ’s the fifth impact large enough to be measurable since the telescope was launched , but the first larger than what had been allowed for in planning . fortuitously , however , the encroachment was still small enough to have only a minor issue on image quality .
“ Micrometeoroid strikes are an unavoidable aspect of operate on any spacecraft , which routinely sustain many impacts over the course of long and productive skill mission in space , ” NASA noted in astatement . The larger the mirror , the more impact will occur , so the JWST ’s designers were fully aware of the threat . Tolerance for very diminished impacts wasengineered intothe telescope ’s intent , for case by adjust the position of underperforming segments . Beyond a certain size impact , however , the impairment will touch image calibre , even if only slightly .
It would have been prissy if the first such impact did n’t occur until after scientific work began so that the first images at least were unfeignedly pristine , but it was not to be . Between May 23 and May 25 , NASA reports , JWST ’s C3 primary mirror segment sustained impact damage beyond the tolerance threshold .
Subsequent testing showed , however , “ The telescope is still performing at a level that exceeds all mission requirement despite a marginally noticeable effect in the data , ” in NASA’swords .
Consequently , we are still on data track to all be dazzled by thefirst scientific images on July 12 , even if they will be slenderly less striking than might have been .
“ We always recognize that Webb would have to weather the quad surroundings , which let in harsh ultraviolet spark and charged particles from the Sun , cosmic rays from alien sources in the galaxy , and episodic strikes by micrometeoroids within our solar system , ” Paul Geithner of Goddard Space Flight Centersaid . “ We designed and build Webb with functioning margin – optical , thermal , electrical , mechanical – to ensure it can do its challenging scientific discipline mission even after many years in space . ”
Having beaten expectations on how light the JWST ’s eye could be kept on the terra firma , this impact will still allow for the scope ’s overall performance above expectations , NASA claims .
The Internet is not alone convinced , however .
The jeopardy of impacts is reduce by turning the JWST ’s mirror aside from incoming meteor showers , at the price of using its fuel up more rapidly , but niggling can be done about sporadic micrometeorites like this one .
Ever keen to regain a facing as silver as a telescope mirror ’s backing , NASA notesthe primary ’s turgid area and close appraisal make it “ A highly sensitive detector of micrometeorites ” . Tracking impacts will meliorate our cognition of their absolute frequency and size visibility .
