Defending Earth: The Race to Stop a Doomsday Asteroid

A huge asteroid, several hundred feet across, is dashing towards Earth through the black nothingness of the cosmos. Grace for the terrible news—there's a 72% chance it might hit Earth in 14 years, with potential impact zones being North America, Southern Europe, and North Africa, some of the most densely populated areas on the planet.

Astronomers have been keeping a close eye on the space invader for a few months, but now it's moved too close to the Sun, making tracking impossible for the next 7 months. Of course, there's a 28% chance that it will miss our planet altogether. But what if it doesn't? Global devastation and destruction—that’s what. Thousands of lives lost, billions and billions of dollars in damage, entire species wiped off the face of the Earth, ruined cities and towns, destroyed fields and forests. We're left wondering whether this is the future waiting for us.

Well, now you can breathe easy. That’s just a hypothetical scenario created by NASA to prepare for a situation like this. The space agency has been thinking about this kind of disaster for years. Even cooler, they run "what-if" asteroid exercises every two years to get scientists, state agencies, and international experts on the same page.

The last one occurred in April—over 100 people took part in that event. During such asteroid drills, experts pretend that a giant space rock is heading our way. Then they work through all the tricky questions they can come up with, like how big is it, where might it hit, and what should we do? It’s like a massive brainstorming session to ensure that if it ever happens, we won’t have to start from scratch.

To make these scenarios feel as real as possible, NASA’s Center for Near-Earth Object Studies gets involved. These are the folks who track real asteroids and calculate their orbits. They simulate months of asteroid observations, complete with uncertainties about its size, trajectory, and potential impact zones. It’s the kind of uncertainty that makes decision-making way harder—just like it would be in real life.

Now, if an asteroid really was aiming at Earth, it wouldn’t be just one country’s problem—it would be everyone’s. That’s why this exercise brings in international experts. In April, for the first time, they worked alongside U.S. agencies like NASA’s Planetary Defense Coordination Office and FEMA to understand how the world might respond to such a crisis, since an asteroid impact would have dire consequences globally.

The big question is: can we actually stop an asteroid from hitting Earth? There are two main options experts consider. First, we could send a spacecraft to gather more info. If we knew more about the asteroid’s size, mass, and orbit, we’d be able to make better decisions about what to do next.

The second option is to try to deflect it. Basically, it means bumping the asteroid off its course so that it misses Earth. This might sound impossible, but NASA’s DART mission has already proven that we can do it. Two years ago, they crashed a spacecraft into a small asteroid called Dimorphos and successfully changed its orbit. It was a huge victory for planetary defense. But missions like that take tons of time to plan, prepare, and carry out. That’s why spotting dangerous asteroids as early as possible is so important.

Currently, NASA is working on a new telescope called NEO Surveyor, which is set to launch in 2027. Unlike good old telescopes, NEO Surveyor is designed to detect even the trickiest asteroids, including ones orbiting close to the Sun. It’ll give us a better chance to act early and potentially stop an asteroid before it becomes a threat.

If you still think that an asteroid impact is something out of science fiction and the threat isn’t real, how about this? Early on Sunday, January 21st, a small asteroid about 3 feet wide entered Earth’s atmosphere and luckily burned up over Germany. NASA’s Scout impact system spotted it 95 minutes before it hit and predicted exactly when and where it would arrive.

At 1:32 a.m. local time, the asteroid turned into a blazing bright fireball, visible as far away as the Czech Republic. Some small meteorites might have landed near the impact site about 37 miles west of Berlin. This is just the eighth time ever that an asteroid has been detected before it hit Earth. It’s a splendid example of how tools like Scout are helping us track asteroids and prepare for anything bigger that might come our way.

Here’s another example. A small asteroid turned the skies over Northeastern Siberia into a breathtaking light show on December 4th, burning up harmlessly in Earth’s atmosphere. The space rock, about 28 inches across, was spotted just hours before it hit, thanks to observations from astronomers around the world. A special alert system managed to predict the impact to within plus or minus 10 seconds.

The asteroid entered Earth’s atmosphere at 11:15 a.m. local time. Authorities were put on alert, but there were no damage reports. NASA’s Asteroid Terrestrial-impact Last Alert System, or ATLAS, spotted the rock 12 hours before it entered the atmosphere. This makes it the fourth imminent impactor—an asteroid discovered within hours of its expected impact—detected this year and the 11th overall.

Now, China also has big plans for planetary defense. They’re working on their first mission to hit an asteroid, and it’s got a double purpose. One spacecraft will crash into the asteroid, and the other will hang back to study the whole thing for up to a year. In other words, it’s not just about protecting Earth—it’s also a way to learn more about the solar system.

The target is an asteroid called 2015 XF261, which is a mouthful and also about 100 feet wide. It flew by Earth recently on July 9th, passing us at 31 million miles. True, it’s pretty far away, but the space traveler was zooming by at a speed of 26,000 mph—30 times faster than the speed of sound.

China is going to send a space probe to study the asteroid. They’re hoping to learn more about its structure and composition, which could help us with future planetary defense missions. Then, they plan to hit the asteroid with another spacecraft to test the impact, and the first space probe will stay there to observe the remains for up to a year.

Timing is critical for this mission, and the asteroid offers some good opportunities in the next few years. In March and May of 2027, the asteroid will pass within 20 million miles of Earth. In April 2028, it’ll get even closer—by that, I mean 13 million miles away.

A year later, in April 2029, the asteroid will end up just 4.2 million miles away, making it the best shot for a mission. Another decent chance will be April 2030, when the asteroid will pass our planet at 4.4 million miles. To give you some context, NASA’s DART mission once targeted an asteroid 7 million miles away, and the trip took 10 months.

So, China’s planners have to pick the right moment, depending on how long their spacecraft will need to get there. The mission is expected to start around 2027. At the same time, this won’t be China’s first attempt to target an asteroid. Back in 2023, they were planning a planetary defense test with a different asteroid, which was also about 100 feet wide. It’s not clear why they switched to the current one—probably because the timing works better.

Most asteroids are basically time capsules from 4.6 billion years ago—leftovers from when the solar system was just forming. Studying them could tell us a lot about how planets, including Earth, came to be. So, China is taking on something that combines planetary defense and pure space science. They’re definitely making big moves in the space exploration game.