Asteroid Apophis Could Collide With Earth's Space Debris During 2029 Flyby
On April 13, 2029, the asteroid Apophis will pass just 32,000 kilometers from Earth. A new study reveals that human-made space debris, rather than the asteroid itself, poses a potential collision risk during the flyby.
A Historic Encounter on Friday the 13th
On April 13, 2029—a date that happens to fall on Friday the 13th—one of the rarest astronomical events of our time will take place. The asteroid Apophis will pass just 32,000 kilometers (about 20,000 miles) from Earth's surface. This trajectory brings it closer to us than some high-orbit geostationary satellites, making it visible to the naked eye across vast regions of Europe, Africa, and Asia.
Despite the terrifying reputation Apophis has maintained since its discovery in 2004, astronomers have gathered enough data to completely rule out any collision with Earth for at least the next century. However, a study published this year in The Planetary Science Journal has flipped the script: instead of examining what the asteroid might do to Earth, researchers investigated whether human-made objects orbiting our planet could strike the asteroid.
Apophis's path to its closest approach will take it directly through a region cluttered with active satellites, decommissioned spacecraft, spent rocket stages, and other space debris. While most of these objects are unlikely to cross its path, researchers discovered that under certain scenarios, the distance between the asteroid and artificial objects could become surprisingly small.
3,250 Objects Analyzed
In the study published by Giulia Schettino and Alessandro Rossi, researchers analyzed 3,250 cataloged objects in high Earth orbits with an apogee—the farthest point in their orbit—exceeding 30,000 kilometers.
This list included active satellites, abandoned spacecraft, rocket bodies, and space debris. Because it is impossible to predict the exact position of every single object in April 2029, the researchers simulated orbital configurations to evaluate potential close encounters.
While the findings do not guarantee that dozens of objects will fly past Apophis, they highlight plausible geometric scenarios. Out of the 3,250 objects analyzed, approximately 219 could theoretically come within 100 kilometers of Apophis, and 70 could close the distance to under 50 kilometers. In four specific orbital groups analyzed in depth, the minimum theoretical distances dropped to just 5, 29, 12, and even 4 kilometers.
The Threat of Space Junk
Active, controlled satellites in geostationary orbit pose little concern. Most are maintained near the equatorial plane, while Apophis will travel on an inclined trajectory, meaning it will bypass them safely.
The real complication lies with uncontrolled space junk. Earth is orbited by abandoned satellites and debris in highly elliptical and inclined orbits that cross the geosynchronous region. Furthermore, existing tracking catalogs do not account for smaller, unmapped fragments.
While researchers define the probability of a collision as "extremely low," they emphasize that an impact with a piece of space debris or an abandoned spacecraft cannot be entirely ruled out. The inherent uncertainty in orbital paths by 2029 leaves a narrow window of possibility. Ironically, Apophis, once feared as a threat to humanity, could arrive in Earth's vicinity only to be struck by human-made debris.
Could an Impact Deflect Apophis Toward Earth?
In short, no.
Researchers emphasize that even if Apophis collides with a defunct spacecraft or space debris, the event would not transfer enough momentum to alter its orbit significantly or turn it into an active threat to Earth.
However, an impact could easily affect the asteroid itself. With a relative flyby speed of approximately 7.4 kilometers per second, even a collision with a small object could transfer enough energy to alter Apophis's rotation, trigger surface disturbances, or eject material.
This presents a potential headache for scientists. The 2029 flyby is considered an extraordinary natural experiment. Earth's gravity is expected to alter Apophis's orbit, change its rotation rate, and potentially trigger surface landslides. Scientists want to measure these precise changes to understand the internal structure of asteroids.
If a piece of space debris strikes Apophis during this window, it will be incredibly difficult for researchers to distinguish between changes caused by Earth's gravitational pull and those caused by the impact.
Space Agencies Prepare for 2029
Both NASA and the European Space Agency (ESA) are actively preparing for the April 2029 encounter.
ESA's Ramses spacecraft is being prepared for a mission to rendezvous with Apophis before its closest approach to Earth, monitoring how our planet's gravity alters its shape, rotation, and surface. Meanwhile, NASA's OSIRIS-APEX spacecraft is scheduled to reach Apophis shortly after the flyby, in June 2029, to study the physical changes up close.
According to ESA, an asteroid of this size—Apophis has an average diameter of about 340 meters—approaches Earth this closely only once every 5,000 to 10,000 years. Named after Apep, the ancient Egyptian god of chaos and destruction, Apophis is set to pass by safely, leaving scientists to wonder if humanity's orbital footprint might be the only thing that strikes it.
