But the direct hit on the mirror surprised NASA and is still being analyzed. NASA revealed the details of the micro-meteorite strike in a blog post dedicated to the website.
“Between May 23 and 25, NASA’s James Webb Space Telescope experienced an impact on one of the mirror core segments,” the NASA Web blog states. “After initial evaluations, the team found that the telescope was still operating at a level that exceeded all mission requirements despite the marginal effect on the data.”
NASA said 18 parts of the mirror can be individually adjusted in response to meteor impacts like this one.
“By adjusting the position of the affected clip, engineers can cancel out part of the distortion…although not all of the degradation can be canceled out in this way,” the NASA blog states. “Engineers have already made the first such adjustment of the affected sector recently… Additional mirror adjustments planned to fine-tune this correction will continue.”
The exact size of a micrometeorite is unknown. It may have been no bigger than a grain of sand, said Heidi Hamill, a planetary astronomer who has long been involved with the telescope. We will use it to study our solar system. Even a small thing can cause damage due to the tremendous speed with which it is done The telescope revolves around the sun and periodically collides with a random particle.
This was a known danger, because although it is secluded in space, it is not as empty as it seems.
“There is absolutely no loss of science from this event. …This telescope is in space — we knew there would be small impacts on it. We were surprised by one hit so soon,” Hamill said.
She said the scientists expected such an effect every five years or so on average.
This unusually complex observatory, heralded as the long-awaited successor to the still-functioning Hubble Space Telescope, orbits the sun in a position that keeps it about a million miles from Earth. It’s too far away for astronauts to visit, and it wasn’t designed to be repaired or hardware swapped.
Webb is going through a “commissioning” phase for several months as his instruments have been calibrated and 18 hexagonal gold-plated mirrors have been positioned to function as one massive mirror about 21 feet in diameter.
So far, NASA has reported nothing but success.
“Astronomers are dizzy at how well things are going (but also worried about not being forgotten, yes we can be superstitious too) and excited to start doing science!” Astrophysicist Michael Turner of the University of Chicago said in an email.
The telescope, which flexed itself upon launch last year, thrived over many days as the sprawling sun shield opened and mirrors spread. The telescope traveled for 29 days to reach its forward location, an orbital location known as L2 where other telescopes worked safely and provided scientists with data on the frequency of micrometeorites.
“While building the telescope, engineers used a combination of simulations and actual impact testing on mirror samples to get a clearer idea of how the observatory was fortified to operate in orbit. This latter effect was greater than designed, and beyond what the team could have tested on Earth,” stated the blog NASA Web.
Webb is different from most telescopes: It’s wide open, and the mirrors are bare rather than enclosed in a tube. The telescope is designed to observe the universe at infrared wavelengths that are outside the detection range of Hubble.
This requires very cold mirrors and tools, This is why mirrors are farther away from the Earth and the Sun at all times. NASA has announced that the “First Light” images will be released on July 12, but has not said what these images will show.
However, he actually produced an image of a star used to focus mirrors. In the background of that image are several galaxies whose light was emitted billions of years ago, and this has impressed astronomers who predict Webb will see into space deeper (and in the past) than Hubble, which launched in 1990.
Webb has multiple goals, including studying the first light in the universe, emitted a few hundred million years after the Big Bang. It will also look at the evolution of galaxies, studying objects in our solar system, including small, icy bodies that orbit the Sun far from Neptune’s orbit.