A recent scientific study confirms that NASA’s impact on an asteroid was enough to alter its orbit, an important step for planetary defense and the imaginations of children around the world. The impact actually occurred back in 2022, when the Double Asteroid Redirect Test (DART) spacecraft, built by the Johns Hopkins University Applied Physics Laboratory on behalf of NASA’s Planetary Defense Coordination Office, deliberately crashed itself into the moon of an asteroid. Yes, the half-mile-wide asteroid Didymos has its own moon, a tiny asteroid named Demovers. The study concluded that NASA hit the little guy so hard that it now orbits the big guy a full 33 minutes faster than before. This, in turn, changes the orbit of the asteroid system around the sun – something humans have never achieved before and may one day save our planet.
You can read the entire study if you want, but the main takeaway is that hitting baby asteroids is only part of the equation. What happened was that the 14,000 mph impact caused damage to Dimorphos (the poor little guy), causing shrapnel (called “ejecta”) from the space rock to be shot into the universe. Of course, the ejecta itself carries momentum. But as you remember from high school, momentum is always conserved, so if a lot of momentum leaves an asteroid pair, the pair itself will lose momentum. In other words, the ejecta multiplies the overall effect of the punch, called the “momentum enhancement factor.” In this case, the study concluded that the ejecta doubled the force of the fist itself!
By definition, slowing down a pair of objects changes their orbit. As Bruce Willis predicted long ago, we humans have proven that we can actually move an asteroid out of the way if necessary. Of course, the hardest part is changing its orbit enough.
Read more: These are your favorite movie cars
We need a bigger DART
Days after NASA’s DART spacecraft struck a smaller asteroid, the Hubble Space Telescope observed two dust tails ejected from the Didymos-Dimorphos asteroid system. – NASA
So how much influence does DART actually have on this pair of asteroids? According to the New York Times, the spacecraft slowed the system’s 76,000 mph orbital velocity by… two inches per hour. Or as NASA puts it, the system’s entire 770-day orbit around the sun was shortened by a full 0.15 seconds. If we want to truly save the planet, we have to hit asteroids harder. Either a bigger DART, or a faster DART, or maybe a lot of small DARTs. Of course, small changes add up to big differences, so if we hit an incoming asteroid early enough, a little DART might be enough.
So while we’re not completely immune to asteroids yet, at least we’ve moved around once. This provides scientists with important data to sort through, which will lead to new developments. Meanwhile, an asteroid called 2024 YR4 is reminding everyone how fragile we actually are. When it was first discovered last year, it was calculated that there was a small chance it would hit Earth with the force of a nuclear bomb. While its threat to Earth (and our moon) is proven, it could quickly become a crisis. With interstellar visitors now bombarding us from the edge of the galaxy, planetary defense is something we need to take seriously as soon as possible.
Want more like this? Join the Jalopnik newsletter to get the latest automotive news delivered straight to your inbox and add us as your preferred search source on Google.
Read the original article on Jalopnik.