In ‘Deep Impact,’ ‘Armageddon Movie” asteroids threaten Earth. Which film was more realistic? NASA scientists weigh in.
Two of Hollywood’s most notable asteroid films, Armageddon and Deep Impact, were released 25 years ago, captivating audiences with their thrilling portrayals of asteroids threatening Earth. However, scientists today assert that these films are far from realistic when it comes to their depiction of asteroids.
In May 1998, Mimi Leder’s Deep Impact hit theaters, chronicling humanity’s struggle against a cataclysmic asteroid. The U.S. government constructs underground shelters for a select few individuals to survive the impending doom. Just seven weeks later, Michael Bay’s Armageddon arrives on the big screen, featuring a group of oil drillers led by Bruce Willis on a perilous mission to destroy the planet-threatening asteroid by detonating a nuclear bomb at its core.
Fast forward 25 years, and the verdict from NASA scientists is clear: both movies stray far from scientific accuracy. According to these experts, Armageddon’s concept of destroying an asteroid by planting a nuclear bomb inside it is unrealistic. On the other hand, Deep Impact’s portrayal of a massive tidal wave wiping out the East Coast is deemed highly improbable.
Renowned astronomer Phil Plait, who has collaborated with NASA on the Hubble telescope, asserts that Deep Impact is the more scientifically grounded of the two films. Plait even highlights a scene in which scientists tether a spaceship to the menacing comet before strategically planting nuclear bombs to alter its trajectory—a method that mirrors a real-life event in September 2016. During this incident, the Philae Lander successfully landed on a comet’s surface to capture crucial images and data.
While Deep Impact earns praise for its scientific basis, planetary scientist Seth Jacobson questions the logic of burying a bomb within an asteroid. He emphasizes that such a strategy would be highly impractical and unlikely to occur in reality.
Plait concurs, explaining that the prevailing flaw in most asteroid movies lies in characters believing that detonating an asteroid is the best course of action. In truth, the more effective approach is to prevent a collision altogether, as demonstrated by NASA’s recent DART mission. This pioneering endeavor employed a kinetic impactor—a spacecraft functioning like a colossal slingshot—to redirect the asteroid’s path.
William Bottke, head of the Department of Space Studies at the Southwest Research Institute, points out that destroying asteroids is a more formidable task than commonly perceived. Even if a nuclear bomb were successful in obliterating an asteroid, the intense heat generated would vaporize surface materials and cause violent expansion. Consequently, the once fast-moving “bullet” would transform into a deadly “shotgun blast.”
Jay Melosh, an esteemed geophysicist specializing in impact cratering, proposed an alternative asteroid deflection method that eschewed bombs altogether. His idea involved flying to the asteroid and concentrating solar energy onto a small point using a large optical surface. This concentrated energy would vaporize the rock, akin to using sunlight and a magnifying glass to burn a piece of paper. By carefully selecting target areas, scientists could create a rock comet, gradually altering the asteroid’s trajectory.
Paul Chodas, the esteemed director of NASA’s Center for Near Earth Object Studies, concurs that Deep Impact holds greater credibility between the two films, despite acknowledging that “both films had a lot of scientific flaws.”
“The more grounded these movies are in scientific realism, the better,” he asserts. “But I also recognize the necessity of making these movies dramatic and entertaining.”
Chodas goes on to explain the potential consequences of a significant impact, stating that the material ejected from the blast could generate firestorms in distant regions and result in long-term global cooling due to the presence of small particles suspended in the atmosphere. Such an event could profoundly impact agriculture, which relies on sunlight, water, and fertile soil for seed germination, potentially leading to widespread famine.
Regarding the theoretical concept of underground shelters saving humanity, Phil Plait, a renowned astronomer, emphasizes the crucial factors of the comet’s size and impact location. Plait states, “If you know where the impact will be and establish a shelter far away, heavily fortified, then… maybe?”
In the case of a so-called “planet killer” comet akin to the catastrophic Chicxulub impactor responsible for the extinction of dinosaurs, the atmosphere would undoubtedly undergo enduring alterations with far-reaching implications for all Earth’s creatures.
However, Seth Jacobson, a planetary scientist and assistant professor at the University of Michigan, proposes that with careful foresight, subsurface survival might be possible during such a period. He highlights the evolutionary history of humans, as descendants of small animals that managed to endure the aftermath of the Chicxulub impact.
Should we harbor concerns about planet-obliterating asteroids? According to the experts, losing sleep over this matter is unnecessary.
Chodas reassures, “There are no large asteroids heading for Earth within our lifetimes.” He further explains that NASA and other global institutions are diligently working to minimize the risk even further by deploying improved telescopes specifically designed for asteroid detection.
The NEO Surveyor mission, scheduled to launch in September 2027, aims to identify at least two-thirds of near-Earth objects larger than 460 feet—those with the potential for regional devastation upon impact.
Moreover, it is worth noting that in the event of a civilization-ending comet, news of its trajectory would become public knowledge at an early stage, prompting a global demand for transparency. This would provide ample time for preparation—a luxury not afforded in Deep Impact, where there was approximately one year before impact, or in Armageddon, where a mere 18 days remained.
Nonetheless, time remains an ever-pressing factor, as demonstrated in these Hollywood storylines.
In scenarios with several decades for preparation, which is the most likely scenario, scientists and policymakers from around the world would collaborate to formulate an action plan. As Jonathan Bottke, an expert in asteroid studies, remarks, “The asteroid would become the most extensively studied celestial object in history, and a comprehensive plan would be devised to carefully alter its trajectory, ensuring a safe distance from Earth. However, if we have only a few years, the utilization of nuclear weapons, coupled with a kinetic impactor, would be the sole viable option for deflection.”
Nevertheless, Chodas asserts that these considerations remain speculative. “We have already identified over 95% of the asteroids capable of posing such a threat, and they are not on a collision course with Earth anytime soon.”
In conclusion, the scientists highlight the positive aspects of Hollywood’s ability to ignite enthusiasm for science, irrespective of its accuracy.
“As a scientist, I can attest that many of us, myself included, were inspired by shows like Star Trek,” admits Plait, “even though the science may sometimes be dubious.”
Bottke emphasizes the value of accuracy, contending that slight modifications to scripts can go a long way.