Toward the end of 2024, astronomers discovered an asteroid that seemed to pose a danger to Earth. Telescopes across the planet are now monitoring Asteroid 2024 YR4 and continue to track the potential danger of it striking Earth in 2032, but what does it mean for us on the ground? What is an asteroid and what steps could you take to prepare for it? Here’s what everyone should know about asteroids, meteors, and other space debris. Plus, the top asteroid mitigation strategies and advice on how to prepare for an asteroid strike from Team Rubicon volunteers.
The Big Rocks That Ended the Dinosaurs
Understanding the difference in space debris can be complex. Asteroids are chunks of rock and metal left over from the formation of the solar system floating through space—NASA estimates that there are at least 1.4 million of them in the solar system, most of which pose no threat to us. Meteors are what happens when objects in space, including asteroids and asteroid pieces, burn up in Earth’s atmosphere.
When a space object doesn’t burn up and hits the planet, it is called a meteorite. Tracking potential meteorites is an essential first step to protecting ourselves from them, a task that history reminds us is urgent.
The most well-known meteorite is probably the one that precipitated the Chicxulub impact event, which ended the era of the dinosaurs 66 million years ago. That asteroid was just over 6 miles in diameter, left a crater 90 miles wide, and caused the extinction of some 75% of all plant and animal species.
A less well-known, but far more recent, meteorite exploded over the Tunguska River in Russia almost 120 years ago. The 1908 Tunguska Event is thought to have been caused by an asteroid estimated to be 130 feet in diameter that blew up around 6 miles above the ground over Siberia. Because the region is so sparsely populated, the exact detonation site of the asteroid was a mystery until 1927, when researchers observed 830 square miles of devastation, evidence of entire herds of dead reindeer, and 80 million trees knocked down.
The vast majority of meteorites are too small to do any damage—less than 4 meters in size—but some recent headlines demonstrate that there are large, dangerous rocks lurking in the sky. According to The Planetary Society, a nonprofit organization co-founded by Carl Sagan, in 2013 what is thought to be an asteroid only 20 meters in diameter exploded with a force more than 30 times the energy of the Hiroshima bomb over the Russian city of Chelyabinsk. While it blasted apart around 30 kilometers above the ground, it damaged 7,200 buildings across six cities and injured 1,500 people.
“The most unsettling thing about the Chelyabinsk event,” said The Planetary Society, “is that nobody saw it coming.”
The Looming Hazard of Space Junk—and Asteroid Impacts
Our planet is bombarded by cosmic rocks daily, and while the majority are completely harmless, we also can’t observe most of them. The science journal Earth and Planetary Science Letters determined that approximately 5,200 metric tons of space dust—micrometeorites smaller than 1 millimeter—rains down on the planet every year. Gonzalo Tancredi, an astronomer at Uruguay’s University of the Republic, has calculated that every day around 17 meteorites touch down somewhere on the surface of the Earth, but that for every one impact recorded, about 770 go unwitnessed.
In addition to the space hazards nature placed around the solar system; humans have been adding an ever-increasing amount of space junk to near-Earth orbit for 68 years—ever since Sputnik launched in 1957. NASA and the U.S. military are actively monitoring and tracking about 20,000 pieces of man-made space debris. According to the Aerospace Foundation, 200 to 400 pieces of space debris that are large enough to be trackable reenter Earth’s atmosphere every year, although less than 100 are large enough to pose a risk to people on the ground.
Perhaps if the Tyrannosaurus rex had arms capable of lifting a telescope or the Stegosaurus had a brain larger than a walnut, the Dinosauria could have developed the Jurassic equivalent of NASA and seen the asteroid coming. Fortunately, we modern humans have NASA, and right now, there is one they see coming.
That potential impact event comes in the form of Asteroid 2024 YR4, which was discovered in December ’24. Estimated to be between 40 to 90 meters in diameter, Asteroid 2024 YR4 appeared for a short period to be aimed straight at us. Then, the chance of it hitting Earth stood at just over 3%.
“‘City-killer’ asteroid headed for Earth,” declared Yahoo News, in a typical headline about the matter. The probability of Asteroid 2024 YR4 crashing into Earth has since fallen to near-zero, although the likelihood of it striking the moon has increased slightly.
“A collision of a NEO [near-Earth object] with Earth is the only natural disaster we now know how humanity could completely prevent,” said NASA Planetary Defense Officer Lindley Johnson.
Or, mitigate against, in the words of disaster responders. Asteroid mitigation strategies include redirecting the objects away from Earth using unmanned spaceships—a strategy tested successfully by a joint project from NASA and the Italian Space Agency called the Double Asteroid Redirection Test in 2022.
Asteroid Mitigation Strategies
Finding near-Earth objects is a key function of the PDCO, especially large asteroids with the potential of making us the next dinosaurs. According to NASA’s Jet Propulsion Laboratory, “several dozen asteroids in the 20-to-40-foot” fly closer to Earth than the moon but “only a fraction of these are actually detected.”
Detecting asteroids and other space objects is only the first step, we also have to prepare for and mitigate against them. Governments and the kinds of nonprofits and agencies that respond to disasters—like Team Rubicon—can start preparing to track, mitigate against, and respond to threats from asteroids such as YR4 now. Space agencies can utilize early detection systems to monitor potential threats and planetary defense programs like NASA’s DART mission aim to deflect hazardous asteroids. For asteroid mitigation strategies, governments, international agencies, and nonprofits like Team Rubicon can develop emergency response plans, including evacuation strategies and infrastructure reinforcement.
It’s also essential that individuals prepare for potential space debris disasters. Here’s advice on how to prepare for an asteroid impact from the disaster response volunteers at Team Rubicon.
How To Prepare For An Asteroid
Stay Informed
Follow NASA’s Near-Earth Object (NEO) program, the European Space Agency’s Planetary Defense Office, and other agencies monitoring asteroids.
Create an Asteroid Impact Emergency Preparedness Kit
Just like it’s important to have a tornado or hurricane disaster preparedness kit, it’s important to prepare for any space debris disaster. Include:
- Food and water (at least two weeks’ supply)
- First aid kit and medical supplies
- Flashlights, batteries, and a hand-crank radio
- Masks (for dust and debris)
Have a Plan to Shelter in Place from Space Debris
Identify sturdy underground shelters or reinforced buildings to protect against shockwaves and debris.
Establish an Asteroid Evacuation Strategy
Be ready to move inland if a strike is predicted near the ocean, which could trigger tsunamis.
Prepare to Serve
Anyone interested in helping others prepare for an asteroid, like Asteroid 2024 YR4, or interested in helping can their communities prepare for, mitigate against, and recover from disasters of all types can sign up now to become a Team Rubicon Greyshirt.
