Asteroid Apophis to Pass Close to Earth in April 2029
The 340-meter-wide asteroid will pass 19,400 miles from Earth, enabling major scientific observations of its trajectory.
Updated on Oct. 24, 2026 in Space
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On April 13, 2029, the 340-meter-wide asteroid 99942 Apophis will pass 19,400 miles from Earth. This rare flyby, which occurs for objects of this size roughly every 5,000 to 10,000 years, will be observed by upcoming space missions.
Why it matters
The event provides a rare opportunity to measure how Earth's gravity alters an asteroid's trajectory and physical state. Scientists have confirmed there is no risk of an impact for at least the next century.
The 340-meter-wide asteroid will pass inside the belt of geostationary satellites, which orbit at 22,236 miles. This trajectory modification by Earth's gravity will be the subject of intensive observation by multiple missions.
The players
RAMSES
An upcoming European Space Agency mission scheduled to launch in 2028 to rendezvous with the asteroid.
OSIRIS-APEX
A NASA mission formerly known as OSIRIS-REx that will analyze the asteroid's physical state following the flyby.
LUMIO
A 12U CubeSat mission designed to monitor meteoroid impacts on the Moon.
The details
The European Space Agency's RAMSES mission will launch in 2028 to rendezvous with Apophis, while NASA's OSIRIS-APEX will study the body after the flyby. Researchers will monitor for physical surface changes caused by the intense tidal forces exerted by Earth as the asteroid passes. The LUMIO CubeSat—a modular 12U satellite designed to detect light flashes from lunar impacts—will also observe the environment during this period.
Timeline
2004: Apophis discovered.
2021: Impact threat ruled out for the next century.
2028: Scheduled launch of RAMSES and LUMIO missions.
April 13, 2029: Apophis makes its closest approach to Earth.
The Tech Race
This mission architecture follows the operational success of the 2023 OSIRIS-REx sample return from asteroid Bennu. It marks a shift from sample retrieval to deep-space gravity interaction analysis.
Observers across Europe, Africa, Asia, Australia, and eastern South America will be able to see the asteroid with the naked eye during the 2029 flyby. No special equipment is required to witness the event, provided weather conditions are clear.
The takeaway
The 2029 flyby offers a rare, natural laboratory for studying planetary gravity interactions that happen once every 5,000 to 10,000 years. Interested parties should monitor the 2028 launch windows for the RAMSES and LUMIO missions, which will provide the primary data from the event.
Further reading
For more on the latest research and monitoring missions, visit the Space section.
Source note: This article includes information reported by Forbes.
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