The Webb Telescope has been hit by something. Here’s what it means for science

NASA’s James Webb Space Telescope (JWST) was hit by a micrometeoroid, which damaged one of the 18 gold-beryllium segments that make up its 6.5-meter main mirror.

This happened between May 23 and 25, according to NASA, with the result being a “marginally detectable effect in the data.” Its C3 segment is believed to have been impacted by small dust particles.

Is it serious? It seems not, despite the impact which slightly misaligned the telescope. Webb “recently suffered an impact to a primary mirror segment,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, in a tweet. “After initial evaluations, the team found that the telescope was still performing at a level that exceeded all mission requirements.”

He added that micrometeoroid strikes are an unavoidable aspect of space operations.

Webb – a $10 billion space telescope that sees into the infrared part of the spectrum – launched on Christmas Day 2021 and has since February orbited the L2 point about a million miles/1.6 million kilometers away of the earth. His “first light” images are due for release on July 12. They should be a dazzling demonstration of what the world’s most advanced space observatory is capable of.

Analyzes and measurements are ongoing, NASA said, but it doesn’t appear these initial images — or the science program that follows — will be greatly affected. This is because engineers were able to adjust its 18 mirrors to correct the damaged segment.

“We always knew Webb would have to contend with the space environment, which includes harsh ultraviolet light and charged particles from the Sun, cosmic rays from exotic sources in the galaxy, and occasional micrometeoroid strikes in our solar system,” said said Paul Geithner, technical assistant project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We designed and built Webb with a margin of performance – optical, thermal, electrical, mechanical – to ensure that it can accomplish its ambitious scientific mission even after many years in space.”

That includes dust-sized particles flying at extreme speeds, though that impact was larger than modeled when Webb was built, NASA said. However, he added that Webb’s initial performance is still well above expectations.

This isn’t the first time Webb has been hit. “Since launch, we’ve had four smaller measurable micrometeoroid impacts that were in line with expectations and this one more recently that is larger than our degradation predictions,” said Lee Feinberg, Elements Manager for the Webb Optical Telescope at NASA Godard. “We will use this flight data to update our performance analysis over time and also develop operational approaches to ensure that we best maximize Webb’s imaging performance for many years to come.”

Although the recent impact is classified as an “unavoidable fortuitous event”, Webb’s engineers are able to maneuver it to protect the optics from known meteor showers.

I wish you clear skies and big eyes.

Leave a Comment