The NASA spacecraft is closing in on the target of a crucial test to deflect asteroid collisions

On September 26th, NASA will attempt to do the impossible by intentionally crashing a spacecraft into an asteroid to alter its orbit slightly. (AFP)

• At around 23,000 kilometers per hour, on September 26th, the spaceship is scheduled to crash into the asteroid moonlet Dimorphous.
• The Dimorphos are not directly dangerous to Earth, but this research is necessary in case a similar situation arises.

WASHINGTON: Surely, the dinosaurs would have appreciated this idea.

As a crucial test of our ability to prevent cosmic objects from destroying life on Earth, NASA will attempt a task humanity has never before accomplished on Monday: purposefully smashing a spacecraft into an asteroid to divert its orbit gently.

The California-launched Double Asteroid Redirection Test (DART) spacecraft is rapidly closing in on the asteroid. It will strike at an estimated 14,000 miles per hour (23,000 kph).

Neither the little asteroid Dimorphos nor the larger asteroid Didymos, which it circles, pose any danger to Earth as they travel around the Sun and zoom past at a distance of about seven million miles.

NASA, however, believes it is necessary to experiment regardless of whether or not a future need arises.

NASA planetary defense officer Lindley Johnson told reporters on Thursday, "This is an exciting time, not only for the agency but in the history of space and the history of humanity, quite frankly."

At 7:14 pm Eastern Time (23:14 GMT), if all goes according to plan, the car-sized spacecraft will collide with the 530-foot (160-meter, or two Statue of Liberty-tall) asteroid, and the whole thing will be broadcast live on NASA's website.

NASA expects that by crashing into Dimorphos head-on, it will be pushed into a more compact orbit, decreasing the time it takes to orbit Didymos from 11 hours and 55 minutes to 10 hours and 45 minutes. This will be observable by ground-based telescopes in the days following the impact.

The proof-of-concept experiment will bring to life an idea previously only explored in science fiction, most notably in films like "Armageddon" and "Don't Look Up."

The primary camera system, dubbed DRACO, will begin transmitting the first images of Dimorphos as the craft accelerates itself into space, flying autonomously for the final leg of the mission like a self-guided missile.

In a recent briefing, Nancy Chabot of the Johns Hopkins Applied Physics Laboratory (APL), which hosts mission control, predicted that the object would appear as a "tiny point of light" before rapidly expanding to fill the entire field of view.

The planetary scientist continued, "These visions will persist until they don't."

A toaster-sized satellite named LICIACube, which split out from DART a few weeks ago, will make a close flyby of the spot minutes later to take pictures of the collision and the ejecta, or the crushed rock thrown off by the impact.

LICIACube's image will be transmitted back in the coming weeks and months.

An assortment of Earth-based and space-based telescopes, including the newly operational James Webb, is keeping an eye on the event in the hopes of catching a glimpse of a brightening cloud of dust.

When a European Space Agency mission called Hera arrives in four years, we'll have a much clearer picture of the system's appearance than we do now. Hera will survey Dimorphos's surface and quantify its mass, which is presented simply as estimated.

Only a minuscule percentage of the solar system's billions of asteroids and comets threaten Earth, and none will for at least 150 years.

NASA's chief scientist, Thomas Zurbuchen, has remarked, "I guarantee you that if you wait long enough, there will be an object."

We know this because of evidence found in geological records, such as the six-mile-wide Chicxulub asteroid that crashed into Earth 66 million years ago, causing a global cooling that ultimately resulted in the extinction of the dinosaurs and seventy-five percent of all other species.

In contrast, even if an asteroid the size of Dimorphos would have more destructive power than any nuclear bomb in history, its effect would be limited to a local area, such as the destruction of a city.

Researchers are also anticipating learning something new that will improve their understanding of asteroids in general.

What DART can do in terms of momentum transfer to Dimorphos depends on whether or not the asteroid is composed of solid rock or more like a "rubbish pile" of boulders bonded by mutual gravitation.

NASA engineers are optimistic that DART's SmartNav guidance system will successfully navigate to the target asteroid. However, they don't know whether the asteroid is shaped like a dog bone or a doughnut.

NASA has another chance in two years to try again; the spacecraft has just enough fuel for one more pass.

But if it works, Chabot says, it will be the first step toward a world that can protect itself from a potentially existential threat.