Move over, Bruce Willis: NASA crashed into an asteroid to test planetary defense

Atomic bombs. That is the go-to deal with any consequences regarding approaching space objects like space rocks and comets, taking everything into account. Films like Profound Effect and Armageddon depend on nukes, conveyed by stars like Bruce Willis, to save the world and convey the show.

But planetary defense experts say in reality, if astronomers spotted a dangerous incoming space rock, the safest and best answer might be something more subtle, like simply pushing it off course by ramming it with a small spacecraft.

That’s just what NASA did on Monday evening, when a spacecraft headed straight into an asteroid, obliterating itself.

In pictures gushed as the effect approached, the egg-formed space rock, called Dimorphos, filled in size from a blip on screen to have its full rough surface come rapidly into center before the sign went dead as the specialty hit, flawless.

Situation unfolded precisely according to plan, they said, with nothing turning out badly. “Supposedly our most memorable planetary safeguard test was a triumph,” said Elena Adams, the mission frameworks engineer, who added that researchers looked on with “both fear and euphoria” as the rocket approached its last objective.

The impact was the culmination of NASA’s Double Asteroid Redirection Test (DART), a 7-year and more than $300 million effort which launched a space vehicle in November of 2021 to perform humanity’s first ever test of planetary defense technology.

It will be about two months, scientists said, before they will be able to determine if the impact was enough to drive the asteroid slightly off course.

“This truly is about space rock avoidance, not disturbance. This won’t explode the space rock,” Nancy Chabot, the DART coordination lead at the Johns Hopkins College Applied Physical science Lab, said prior. She says the crash is only a prod that is like “running a golf truck into the Incomparable Pyramid.”

Tweaking a space rock’s orbit

Dimorphos is around 7 million miles away and poses no threat to Earth. It’s about 525 feet across and orbits another, larger asteroid.

NASA officials stressed that there was no way their test could have turned either of these space rocks into a menace.

“There is no situation wherein either body can turn into a danger to the Earth,” says Thomas Zurbuchen, partner executive for the science mission directorate at NASA. “It’s simply not experimentally imaginable, as a result of energy protection and different things.”

Instead, the impact should slightly shorten the time it takes for Dimorphos to orbit its bigger asteroid pal. Right now, a full circuit takes 11 hours and 55 minutes. The DART impact should change the path of Dimorphos so that it moves closer to the big asteroid and takes less time to go around, doing so perhaps once every 11 hours and 45 minutes.

These two space rocks are up until this point away that telescopes see them as a solitary place of light that darkens and lights up as Dimorphos goes around. Pictures from the DART shuttle’s camera were the primary opportunity that researchers needed to see the space rock they had been attempting to hit.

The spacecraft’s onboard navigation systems initially targeted the larger and easier-to-spot asteroid, only switching their attention to Dimorphos in the last hour of the mission.

In the final minutes before impact at 14,000 miles per hour, NASA lost the ability to send commands to the spacecraft as scientists simply watched and waited. Cheers erupted in the control room as the screen went red from loss of signal.

A more modest space apparatus close by was watching, and will send pictures back to Earth throughout the next days. Telescopes on every one of the 7 landmasses, as well as space telescopes like James Webb, will likewise see the impact and its result for a really long time, mentioning objective facts that will allow stargazers exactly to quantify how the space rock’s way got changed.

What’s more, in a couple of years, the European Space Agency will send a mission called Hera out to this double asteroid system, letting scientists gather even more information on the impact’s effects.

All of this should reveal just how an asteroid reacts to a deliberate push, and scientists can take that information to help them make contingency plans to get ready for future threats.

“The reality is, it’s something extraordinary,” says Ed Lu, who fills in as chief head of the Space rock Organization, a program run by a not-for-profit committed to planetary safeguard. “Sometime in the not so distant future, we will find a space rock which has a high likelihood of stirring things up around town, and we will need to redirect it.”

When that happens, says Lu, “we should have, in advance, some experience knowing that this would work.”

Lots of asteroids have yet to be found and tracked

Still, the folks working on the DART mission seem to understand that their project can sound kind of far out.

“We’re moving a space rock. We are changing the movement of a characteristic heavenly body in space. Humankind has never done that,” says Tom Statler, NASA’s DART program researcher. “This is stuff of sci-fi books and truly cheesy episodes of Star Trip from when I was a youngster, and presently it’s genuine. Furthermore, that is somewhat shocking that we are really doing that, and what that bodes for the eventual fate of what we can do.”

NASA tracks lots of space rocks, especially the larger ones that could cause extinction-level events. Thankfully, none currently threaten Earth. But many asteroids the size of Dimorphos haven’t yet been discovered, and those could potentially take out a city if they came crashing down.

That’s why NASA’s Planetary Defense Coordination Office wants to launch the asteroid-hunting space telescope NEO Surveyor, which could go up in 2026 or 2028, depending on how much money Congress allocates.

“It’s something that we want to finish so we understand what’s out there and understand what’s coming and have satisfactory chance to get ready for it,” says Lindley Johnson, NASA’s Planetary Guard Official.

He says such a telescope could give Earthlings years or decades or even centuries of warning about space rocks on an alarming path — plenty of time to come up with a solution, whether it’s a “kinetic impactor” like DART or maybe another kind of spacecraft that would just fly next to a worrisome asteroid and use gravity to tug it gently away.

All of that is very different from the usual way that Hollywood portrays saving the planet, notes Johnson.

“They need to make it invigorating, you know, we track down the space rock just a brief time before it will effect, and everyone goes around with their hair ablaze,” he says. “That is not the method for doing planetary protection.”