(Credit - Live Science)
31,600km Earth Flyby in 2029: Asteroid Apophis to Be Visible to Billions
The 340-meter asteroid 99942 Apophis will pass within 31,600 kilometers of Earth on April 13, 2029, making a historic flyby that astronomers estimate could be visible to nearly two billion people during its closest approach. Astronomical observers and space research institutions across multiple continents will track the skyscraper-sized space rock as it sweeps well inside the orbit of Earth’s geostationary satellites over a seven-hour window.
Peak Viewing Above the North Atlantic Will Bring Magnitude 3.1 Brightness
At its closest approach at 21:45 UTC (5:45 p.m. EDT), Apophis will reach its point nearest to Earth over the North Atlantic Ocean, reaching a magnitude 3.1 brightness that makes it visible to the naked eye under clear, dark skies. Detailed visibility mapping presented by retired cartographer Michael Zeiler and astronomer Rick Fienberg at the University of Padua charts the space rock appearing not as a blazing meteor, but as a point-like speck of light advancing across the sky by approximately the apparent width of a full moon every minute.
While theoretical visibility calculations indicate up to 90 percent of the global population lives in regions where the asteroid passes overhead, actual viewing will depend on local cloud cover and light pollution. Earlier in the flyby sequence, up to 4.5 billion people across Australia and Asia will sit beneath its orbital track, before the line of visibility shifts toward northern Africa, parts of Europe, and eastern South America during peak proximity.
Following the encounter, Earth’s gravitational force will alter the orbit of Apophis from an Aten-class asteroid to an Apollo-class asteroid. The OSIRIS-REx spacecraft, which returned a sample from asteroid Bennu in September 2023, will execute a rendezvous with Apophis days after the flyby, beginning an 18-month extended mission to fire its thrusters near the surface and study the asteroid’s exposed subsurface composition.
