A JAMES Webb Space Telescope mirror was struck by a micrometeoroid last month, but it is expected to continue to function normally, said Nasa yesterday.

“After initial assessments, the team found that the telescope is still performing at a level that exceeds all mission requirements despite a marginally detectable effect in the data.

“Webb’s beginning-of-life performance is still well above expectations, and the observatory is fully capable of performing the science it is designed to achieve.”

One of the space observatory’s primary mirror segments suffered an impact from a micrometeoroid, which tends to be smaller than a grain of sand, between May 23 and 25.

The telescope, expected to cost Nasa nearly US$10 billion (RM43 billion), is among the most expensive scientific platforms ever built, comparable to its predecessor Hubble and the Large Hadron Collider at CERN.

Webb’s mission includes the study of distant planets, known as exoplanets, to determine their origin, evolution and habitability, and it is expected to produce “spectacular colour images” of the cosmos in mid-July.

It spent the past few months aligning its instruments in preparation for the big reveal.

Nasa said micrometeoroid strikes are an “unavoidable aspect of operating any spacecraft” and “were anticipated when building and testing the mirror”.

“This most recent impact was larger than was modelled, and beyond what the team could have tested on the ground.”

Nasa Goddard Webb optical telescope element manager Lee Feinberg said “with Webb’s mirrors exposed to space, we expected that occasional micrometeoroid impacts will gracefully degrade telescope performance over time”.

“Since launch, we have had four smaller measurable micrometeoroid strikes that were consistent with expectations.”

The United States space agency said to protect Webb, flight teams can turn the optics away from known meteor showers.

The May micrometeoroid strike is not the result of a meteor shower but an “unavoidable chance event”, it added. – AFP, June 10, 2022.