Giant asteroids hurling their way towards Earth are harder to destroy than scientists –or Hollywood screenwriters — previously thought, according to new research.

John Hopkins researchers found that asteroids couldn’t be completely shattered by foreign objects — including ones launched to stop an end-of-days-style collision, as seen in sci-fi films such as “Deep Impact.”

“It is only a matter of time before these questions go from being academic to defining our response to a major threat,” said K.T. Ramesh a professor of astronomy at the Johns Hopkins University, who contributed to the report. “We are impacted fairly often by small asteroids, such as in the Chelyabinsk event a few years ago.”

To test whether the massive space rocks could be destroyed, scientists plugged factors such as mass, temperature and material brittleness into a computer program — and simulated a 15-mile-long object smashing into an asteroid at roughly three miles per second, according to the study, which is set to be published in the journal Icarus on March 15.

Unlike a similar study from 2000 that showed asteroids could be completely destroyed by the impact, they found that the core of the asteroid was damaged but not completely broken, researchers said.

Instead of smashing the space rock in to a “rubble pile,” the center of the asteroid merely cracked but didn’t completely break — allowing it to continue to catapult through space, according to the report.

The previous study, which was not as detailed, failed to take into consider cracks in the astroid, which slowed its speed and made the impact of the two objects less powerful, researchers said.

“We used to believe that the larger the object, the more easily it would break, because bigger objects are more likely to have flaws. Our findings, however, show that asteroids are stronger than we used to think and require more energy to be completely shattered,” says lead researcher Charles El Mir, of the Johns Hopkins University’s Department of Mechanical Engineering.

He added, “It may sound like science fiction but a great deal of research considers asteroid collisions.”

This story originally appeared in the New York Post. A previous version of this story said that K.T. Ramesh was a professor at the University of Maryland.