Skip to main content

How NASA is dealing with micrometeoroids threatening James Webb

In June this year, NASA revealed that the James Webb Space Telescope had suffered from a micrometeoroid impact, in which a small space rock had caused some damage to one of the telescope’s 18 primary mirror segments. Although the damage was not serious enough to interfere with science operations, it did raise concerns about how much damage the telescope could suffer from similar impacts in the future. Now, NASA has shared its plan to deal with the issue of such impacts as Webb ages.

The Webb team knew that some impacts from micrometeoroids would be inevitable, as there are many such small particles in the area where Webb orbits around the sun. The telescope was designed to withstand small impacts, but a NASA working group concluded it was just bad luck that it was hit by a larger impact so soon after its launch in December 2021. An impact of that size was a “rare statistical event,” NASA said, both in that it was larger than most such impacts and that it happened to hit a particularly sensitive part of the telescope.

Recommended Videos

​​“We have experienced 14 measurable micrometeoroid hits on our primary mirror, and are averaging one to two per month, as anticipated. The resulting optical errors from all but one of these were well within what we had budgeted and expected when building the observatory,” said Mike Menzel, Webb lead mission systems engineer, in a statement. “One of these was higher than our expectations and prelaunch models; however, even after this event our current optical performance is still twice as good as our requirements.”

To protect Webb from such impacts in the future, the telescope will be used in such a way that it avoids facing the “micrometeoroid avoidance zone.” This helps avoid micrometeoroids striking the telescope’s primary mirror head-on, as these strikes are generally faster and are particularly damaging. The telescope will still be able to image all regions of the sky, but it will point at different regions at different times of the year to minimize the risk of impacts. This will begin with the second year of Webb science observations, called Cycle 2, which will start in July 2023.

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
James Webb observes what happens when a planet is swallowed by a star
NASA’s James Webb Space Telescope’s observations of what is thought to be the first ever recorded planetary engulfment event revealed a hot accretion disk surrounding the star, with an expanding cloud of cooler dust enveloping the scene. Webb also revealed that the star did not swell to swallow the planet, but the planet’s orbit actually slowly decayed over time.

As planetary demises go, this one is pretty grisly: a planet falls closer and closer to its host star, getting hotter and hotter as it spirals inward, until it finally falls past the point of no return and is swallowed by the star in a tremendous flash of light. That's what happened in an event called ZTF SLRN-2020, and now the James Webb Space Telescope has been observing the aftermath to learn more about this rare event.

“Because this is such a novel event, we didn’t quite know what to expect when we decided to point this telescope in its direction,” said lead researcher Ryan Lau of NOIRLab, who used Webb's MIRI (Mid-Infrared Instrument) and NIRSpec (Near-Infrared Spectrograph) instruments to make observations. “With its high-resolution look in the infrared, we are learning valuable insights about the final fates of planetary systems, possibly including our own.”

Read more
James Webb captures a rare astronomical ring in the sky
This new NASA/ESA/CSA James Webb Space Telescope Picture of the Month features a rare cosmic phenomenon called an Einstein ring. What at first appears to be a single, strangely shaped galaxy is actually two galaxies that are separated by a large distance. The closer foreground galaxy sits at the center of the image, while the more distant background galaxy appears to be wrapped around the closer galaxy, forming a ring.

A striking new image from the James Webb Space Telescope shows a rare object called an Einstein ring. This shows what appears to be a ring-shaped object in the sky, but is actually created by two separate galaxies and the epic forces of gravity.

There's a useful astronomical phenomenon called gravitational lensing, in which a large object like a galaxy or a cluster of galaxies has so much mass that it actually bends spacetime. If a massive object sits in front of a more distant object, as seen from Earth, the massive object can act like a magnifying glass, letting us see the very distant object in more detail than would normally be possible. This is a relatively common finding in astronomical images, and is one way that scientists are able to study extremely distant galaxies.

Read more
James Webb captures gorgeous image of a Cosmic Tornado
The NASA/ESA/CSA James Webb Space Telescope observed Herbig-Haro 49/50, an outflow from a nearby still-forming star, in high-resolution near- and mid-infrared light with the NIRCam and MIRI instruments. The intricate features of the outflow, represented in reddish-orange color, provide detailed clues about how young stars form and how their jet activity affects the environment around them. A chance alignment in this direction of the sky provides a beautiful juxtaposition of this nearby Herbig-Haro object (located within our Milky Way) with a more distant, face-on spiral galaxy in the background.

The James Webb Space Telescope has captured another stunning image of space, this time showing the dramatic scenes around a baby star. Very young stars can throw off powerful jets of hot gas as they form, and when these jets collide with nearby dust and gas they form striking structures called Herbig-Haro objects.

This new image shows Herbig-Haro 49/50, located nearby to Earth at just 630 light-years away in the constellation Chamaeleon. Scientists have observed this object before, using the Spitzer Space Telescope, and they named the object the "Cosmic Tornado" because of its cone-like shape. To show the impressive powers of James Webb to capture objects like this one in exquisite detail, you can compare the Spitzer image from 2006 and the new James Webb image.

Read more