On April 13, 2029, a space rock comparable in height to the Eiffel Tower will skim just 32,000 kilometers above Earth’s surface, slipping beneath the altitude where geostationary satellites operate. Millions of people across three continents could witness the close pass without telescopes.
The asteroid, named 99942 Apophis, poses no collision threat. NASA has confirmed that tracking data rules out any impact for at least a century. Instead, the flyby presents a rare scientific and observational opportunity.
The European Space Agency projects roughly two billion people across Europe, Africa, and parts of Asia may glimpse Apophis with unaided eyes, assuming clear and dark skies. The asteroid should reach third magnitude, similar to a modest star, and cross an apparent distance wider than the full Moon per minute near its peak. Observers will see a slowly shifting point of light, not a fireball or streak. Apophis never enters the atmosphere.
The 32,000-kilometer figure refers to the gap between the asteroid and Earth’s surface, not the center-to-center distance. Adding Earth’s radius explains why different sources cite varying numbers. NASA lists Apophis with a mean diameter near 340 meters and a long axis of at least 450 meters, while ESA commonly cites roughly 375 meters. Radar data indicate an elongated, possibly two-lobed shape, so mean diameter and maximum dimension should not be conflated.
A flyby this close by an asteroid exceeding 300 meters in width occurs roughly once every millennium, according to older estimates. Newer assessments suggest even rarer intervals, with some agencies citing every 5,000 to 10,000 years. These figures represent statistical recurrence rates, not timed predictions.
Apophis was discovered in 2004, and initial orbital calculations briefly allowed a tiny 2029 impact possibility. Radar measurements from Goldstone and Green Bank in March 2021 eliminated that risk and removed the asteroid from NASA’s impact watchlist.
Scientific interest remains intense. Earth’s gravity will bend Apophis’s orbit and tidal forces may reshape its surface, alter its spin, or expose fresh material. NASA’s OSIRIS-APEX spacecraft, formerly OSIRIS-REx, will rendezvous after the encounter. ESA and Japan are developing Ramses to arrive beforehand and monitor changes in real time.
For ground observers, the challenge lies in knowing the track, finding dark skies, and looking at the right moment. The asteroid will vanish quickly, but the data collected may inform planetary defense models for decades.
