For decades, the story of asteroid Apophis has been one of calculated risk and scientific intrigue. Discovered in 2004, this city-block-sized space rock initially made headlines for a worrying, though eventually dismissed, probability of impacting Earth in 2029. Now, that very same close flyby—an event without precedent in recorded history—is set to become one of the most significant astronomical events of the century, and space agencies are preparing to seize a once-in-a-millennium opportunity.
The European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) are advancing plans for a daring joint mission to study the 1,230-foot (375-meter) asteroid as it makes an exceptionally close pass by Earth on Friday, April 13, 2029. This international effort aims to transform a celestial close encounter into a profound scientific bonanza, yielding insights into the formation of our solar system and bolstering our planetary defense capabilities.
The 2029 Flyby: A Celestial Spectacle
On that spring night in 2029, Apophis will be anything but subtle. For a few hours, observers across parts of Europe, Africa, and Asia will be able to witness the asteroid with the naked eye as it streaks through the sky, a rare event for an object of its size. It will pass within a mere 20,000 miles (32,000 kilometers) of Earth’s surface—closer than some of our highest-altitude satellites and ten times nearer than the Moon.
While astronomers have definitively ruled out any risk of an impact for at least the next century, the gravitational forces of such an intimate encounter are expected to fundamentally alter the asteroid itself. This presents a unique, natural experiment that scientists are eager to observe.
"The 2029 flyby is a natural experiment that nature is throwing at us," said an ESA mission scientist. "The tidal forces from Earth's gravity will likely cause landslides and disrupt the asteroid's surface and interior. It’s an incredible chance to observe almost in real-time how these small bodies behave and respond to external forces."
The Ramses Mission: Europe’s Rapid Response Reconnaissance
At the heart of the European contribution is the Rapid Apophis Mission for Space Safety (Ramses). This ambitious spacecraft would need to launch in 2027 to rendezvous with Apophis before its historic close encounter with Earth. The goal is to get a detailed "before" picture of the asteroid's physical characteristics.
Once on station, Ramses would spend months meticulously mapping Apophis’s shape, surface, interior structure, and chemical composition. It would then have a front-row seat to document the changes wrought by Earth’s gravity during the flyby itself. This "before-and-after" analysis is the key to unlocking secrets about the asteroid's cohesion, density, and porosity—critical data for any future strategy to deflect a hazardous asteroid.
The mission is currently undergoing a formal review process, with a decision expected by the end of 2025. As detailed in a recent announcement, ESA and JAXA advance potential Apophis mission collaboration, the two agencies are actively working to align their objectives and technical capabilities for a joint endeavor.
A Legacy of Asteroid Exploration: OSIRIS-APEX and DESTINY+
The ESA-JAXA mission will not be alone in its scrutiny. NASA is also in on the act with its OSIRIS-APEX spacecraft (formerly OSIRIS-REx, which returned samples from asteroid Bennu in 2023). Instead of retiring, the veteran probe is on an extended mission to rendezvous with Apophis after the 2029 flyby.
While Ramses aims to capture the transformation as it happens, OSIRIS-APEX will perform a crucial post-flyby examination. You can read more about its journey on the NASA Science mission page for OSIRIS-APEX. This one-two punch of observations—from two highly experienced spacecraft—will provide an unparalleled, multi-perspective dataset.
JAXA, with its own illustrious history of asteroid sample return missions like Hayabusa2, brings its proposed DESTINY+ mission into the fold. While its primary target is a different asteroid, the agency's expertise in close-proximity operations and its potential for technological contribution to the joint effort with ESA are invaluable. The collaboration leverages the best of both agencies' engineering and scientific prowess.
Why It Matters: More Than Just Scientific Curiosity
The study of Apophis extends far beyond pure academic interest. It sits at the core of a growing global effort in planetary defense—the field dedicated to identifying and mitigating threats from near-Earth objects (NEOs).
By understanding the internal structure and strength of an asteroid like Apophis, scientists can better predict how similar objects might respond to a kinetic impactor, like the one tested in NASA’s DART mission, or other deflection techniques. This knowledge is essential for designing effective missions to protect our planet should a future threat be identified.
As ESA states on its dedicated Ramses mission portal, "The findings from Ramses will turn the Apophis flyby into a giant natural experiment, yielding... invaluable knowledge for planetary defense."
The close approach of Apophis in 2029 is a moment of both spectacle and profound scientific importance. It’s a stark reminder of our dynamic solar system and a test of our species' readiness to understand and navigate it. Thanks to the collaborative spirit of ESA, JAXA, and NASA, this ultra-rare cosmic event will be transformed from a celestial curiosity into a cornerstone of planetary science and safety.