Should We Be Concerned About Asteroid Impacts on Earth? What You Need to Know

Deep in the cold void of space lies a potential asteroid threat that could obliterate most life on Earth. Is such a fate unavoidable? Can we potentially avert disaster, or are we fated for a catastrophic end similar to the dinosaurs? Here’s what science reveals.

The asteroid that led to the extinction of the dinosaurs 66 million years ago measured at least 10 kilometers across. Its massive impact resulted in catastrophic tsunamis, widespread wildfires, and global darkness. Estimates of Earth’s crater history suggest that an asteroid of this magnitude collides with Earth roughly every 60 million years. Smaller asteroids, around 1 kilometer in diameter, impact the Earth approximately every million years, with the last significant event occurring around 900,000 years ago. These statistics are understandably alarming.

However, unlike the dinosaurs, humans possess the unique ability to observe and analyze our universe. Consequently, scientists are diligently working global efforts to catalog asteroids and assess which pose a threat.

Fortunately, among the thousands of near-Earth objects currently monitored by astronomers, only 35 present a risk greater than 1 in 1 million of colliding with Earth in the next century. Moreover, the vast majority of these potential threats measure less than 100 meters in diameter. So, is an extinction-level asteroid likely to strike during our lifetime? The probability is extremely low.

Nonetheless, discerning readers will note phrases like “about the asteroid we are tracking,” “a small possibility,” and “almost.” Such wording implies that we can’t confirm we’ve detected every asteroid out there. Rarely, we receive sensational news about newly discovered asteroids nearing Earth, but in many instances, these rocks pass safely by.

To estimate the number of detected asteroids, astronomers calculate three factors: the total number of known asteroids, the volume of the sky explored, and the power of the telescopes used. They estimate that all asteroids larger than 10 kilometers posing a danger to Earth have been accounted for. Breathe easy; the likelihood of experiencing an event similar to the dinosaurs’ extinction is minimal.

Currently, about 80 percent of kilometers-wide asteroids have been identified, indicating a low chance of unforeseen impacts. Asteroids smaller than 100 meters pose little threat, and incidents like the Chelyabinsk meteor in 2013 typically result in minor damage as they incinerate upon atmospheric entry.

However, the so-called “urban killer”—the asteroids within the 100-meter range—remain concerning, as we have only detected less than half of these. If you’re worried about asteroids, these smaller threats warrant closer scrutiny.

Luckily, we have technology at our disposal that differentiates us from the dinosaurs. Our first line of defense involves monitoring space with advanced telescopes. Continuous efforts to observe near-Earth objects are underway, highlighted by the upcoming launch of the NEO Surveyor next year, which aims to greatly enhance our capacity to track these asteroids.

The second defense mechanism provided by space exploration is the capacity to respond if a threatening asteroid is detected. NASA’s 2022 Double Asteroid Redirection Test demonstrated the potential to redirect an asteroid, ensuring we could alter its path if necessary. Provided we have sufficient notice—typically requiring several years of monitoring—we can adjust trajectories to avert collision.

In the event that an asteroid does hit Earth, the impact would be a natural yet predictable disaster. If an asteroid strikes, it could crash into the ocean or an uninhabited region. According to the World Economic Forum, less than 15 percent of the Earth’s lands (under 4.3 percent of the total surface area) have been significantly modified by humans, with even fewer areas inhabited.

If an asteroid were to threaten one of these few populated areas, we have strategies similar to managing any natural disaster: evacuation, damage control, and sheltering in place. Strengthening our overall disaster response capabilities prepares us for such scenarios and aids in managing more plausible and unpredictable disasters.

So, returning to our initial question: Are asteroids inevitable? Absolutely. Is there a solution? Very likely. Will we face a fate akin to the dinosaurs? If so, it remains far off in the future. Instead of succumbing to worry, invest your energy in preparedness—learn about natural disaster responses and keep an eye on asteroids like the vigilant scientists do.