On June 8, NASA revealed that its powerful new space observatory, the James Webb Space Telescope, now has a small dome in one of its primary mirrors after being attacked by larger-than-expected microscopic meteors. deep space. The news was a bit shocking because the impact came just five months after the space telescope’s tenure, but strikes like these are simply an inevitable aspect of space travel and more attacks are sure to come.
Despite what its name suggests, the space is not completely empty. Within our solar system, small pieces of space dust travel through the regions between our planets at gigantic speeds that can reach tens of thousands of miles per hour. These tiny meteorites, no bigger than a grain of sand, are usually small pieces of asteroids or comets that broke and now orbit around the sun. They are everywhere. An approximate estimate of small meteorites in the inner solar system Its combined total mass is estimated at 55 trillion tons (if all were combined into one rock, it would be about the size of a small island).
Small pieces of space dust spread across the regions between our planets at an enormous speed
This means that if you send a spacecraft into deep space, your instruments will surely collide with one of these small pieces of space rock at some point. Knowing this, spacecraft engineers will build their vehicles with certain protections to protect themselves from micrometeorite shocks. They often incorporate something called Whipple shielding, which is a special multi-layered barrier. If the shield is hit by a small meteor, the particle will pass through the first layer and fragment further, so that the second layer will collide with smaller particles. This shield is typically used around sensitive components of a spacecraft to provide additional protection.
But with NASA’s James Webb Space Telescope, or JWST, it’s more complicated. The mirrors of gold-plated telescopes must be exposed to the space environment in order to properly collect light from the distant universe. And while these mirrors are built to withstand some impact, they’re a bit of a sitting duck for larger micrometeoroid bumps, like the one that hit JWST in May. Although the micrometeorite was still smaller than a grain of sand, it was larger than NASA expected, enough to damage one of the mirrors.
Spacecraft operators are modeling sets of microscopic meteorites in space to better understand how often a spacecraft can hit any part of the solar system and what size particles could hit its instrument. But until then, it is not an infallible system. “Everything is a possibility,” says David Malaspina, an astrophysicist at the University of Colorado who focuses on the effects of cosmic dust on spacecraft. threshold. “You can say, ‘I can hit this particle size. “But whether you do it or not is due to chance.”
Examples of different types of shielding WhipplePicture: NASA
Micrometeorites have a wide range of source histories. They could be leftover products of high-speed collisions in space, crushing space rocks into small pieces. Asteroids and comets are also bombarded over time by space particles and photons from the Sun, causing small pieces. The asteroid can also approach a planet as large as Jupiter, where the strong gravitational pull attracts chunks of rock. Or an object could get too close to the sun and heat up too much, causing the rocks to expand and break into pieces. There are even microscopic interstellar meteorites passing through our solar system from distant cosmic neighborhoods.
Micrometeorites have a wide range of source histories
The speed at which these particles move depends on the region of space they are in and the path they take around our star, averaging about 45,000 miles per hour, or 20 kilometers per second. Whether or not it will affect your spaceship also depends on where your spacecraft lives in space and how fast it moves. For example, NASA’s Parker solar probe is the closest artificial object to the sun at the moment, moving at a maximum speed of over 400,000 miles per hour. “It depends on the 4-yard line, compared to the Earth which lies to an extreme region,” says Malaspina, who has focused on studying the effects of micrometeorites on the Parker solar probe. It also moves through the densest part of a region called the zodiac cloud, which is a thick disk of space particles that permeates our solar system. Thus, the Parker Solar Probe suffers a sand attack more frequently than the JWST, and collides with these particles at incredibly higher speeds than a telescope would.
The Parker Solar Probe provides us with a better understanding of micrometeoroids around the Sun, but we also have a good understanding of the population around the Earth. When a small meteor hits the upper atmosphere of our planet, it burns and creates meteor smoke: tiny, measurable smoke particles. The amount of this smoke can tell us how much dust is hitting the Earth over time. In addition, experiments were conducted at the International Space Station, where the material was installed on the outer surface of the orbiting laboratory to see how often it was bombed.
NASA Parker Solar Probe Art ExhibitionPhoto: NASA
Although JWST lives a million miles from Earth, it is still relatively close. Scientists also have an idea of what’s out there based on other missions that have been sent into orbit similar to JWST. Most things that touch the telescope are not so important. “The spacecraft hit little kids all the time,” Malaspina says. “Little by little, I’m referring to micron fractions, much smaller than human hair. And for the most part, spacecraft don’t even notice.” In fact, JWST was already hit by four small meteorites before hitting the largest micrometeorite in May.
“You just have to be more discriminating with the help you render toward other people.”
NASA modeled the micrometeorite environment before the launch of JWST, but in light of the recent impact, the agency has created a new team to improve its models and better predict what could happen to the telescope after future impacts. Modeling current micrometeorites will attempt to predict things such as how debris will propagate through an orbit if an asteroid or comet crashes. This type of wreck is more dynamic, Malaspina says, making it harder to predict.
However, at the end of the day, the prediction will simply give you more insight when a spacecraft can hit a large chunk of dust. Occasional effects like this are simply inevitable. The JWST eruption would continue over time, but this was a possibility for which NASA had always been prepared. “You just have to live with the possibility that you will eventually run into some dust-sized particles and do your best with engineering,” says Malaspina.