Since its launch on December 25, 2021, NASA James Webb Space Telescope (JWST) was bombarded by at least 19 tiny space rocks – including a large one that left noticeable damage on one of the telescope’s 18 gold-plated mirrors.
In a sprawling new status report published in the Preprint Database arXiv.org (opens in a new tab), NASA researchers have shared the first images showing the extent of this damage. Seen on the C3 mirror in the lower right corner of the image, the impact site appears as a single bright white bump staining the surface of the gold mirror.
The impact – which likely happened between May 23 and 25 this year – left “incorrigible” damage to a tiny part of this mirror, the report says. However, this small bump does not seem to have inhibited the performance of the telescope at all. In fact, the JWST’s performance exceeds expectations “in almost every way”. (Good news for fans of stunning space imagery.)
Related: The first images from the James Webb Space Telescope are here, and they’re spectacular
Tiny rocks known as micrometeoroids are an all-too-familiar threat to spacecraft in near-Earth orbit. The US Space Surveillance Network keeps track of more than 23,000 pieces of orbital debris measuring more than the size of a softball – however, the millions of nearby space chunks that are smaller than that are almost impossible to monitor. .
Instead, NASA and other space agencies predict unavoidable impacts.
“Inevitably, any spacecraft will encounter micrometeoroids,” the new report says. So far, six micrometeoroids have left noticeable “deformations” on the JWST mirrors, amounting to about one noticeable impact per month since the telescope’s launch.
All of this is within the realm of expectation. During the construction of the JWST, the engineers intentionally hitting mirror samples with micrometeoroid-sized objects to test how such impacts would affect telescope performance.
What was unexpected, however, was the size of the larger impactor that dented the C3 mirror. This space rock was apparently larger than the team had prepared for, and researchers are now trying to assess what impact more strikes like this might have on the JWST.
The new status report, which has not yet been peer-reviewed, was written by more than 200 scientists working at NASA, the European Space Agency (a collaborator in the construction and launch of the JWST, with the NASA and the Canadian Space Agency) and other scientific institutions around the world. Despite the unexpected impact on the C3 mirror, the researchers found that the telescope was working perfectly after the 6-month commissioning process and had a bright future of discovery ahead of it.
“JWST was envisioned ‘to enable fundamental breakthroughs in our understanding of the formation and evolution of galaxies, stars, and planetary systems,'” the report states. “We now know for sure that will be the case.”
Originally posted on Live Science.