In 2029 the asteroid Apophis will pass closer to us than some of our own satellites

A quarter-mile-wide asteroid named for an ancient Egyptian god of chaos is on course to swing past Earth closer than the ring of satellites that carry weather forecasts and television signals around the planet. Apophis was once considered a genuine impact concern shortly after its 2004 discovery, before additional tracking ruled out any collision for at least the next century. What is left is something rarer: a precisely predicted, perfectly safe close pass that will be visible without a telescope from large parts of the world.

Close approaches by near-Earth asteroids are not unusual on their own; smaller, less-studied rocks slip past Earth at various distances on a regular basis without drawing much public attention. What sets the 2029 Apophis pass apart is the combination of the object’s size, the precision with which its path has already been mapped years in advance, and the sheer proximity involved, all of which have turned a single flyby into a coordinated international research opportunity rather than a routine tracking exercise.

How close is closer than geosynchronous satellites

On April 13, 2029, Apophis will pass roughly 32,000 kilometers, or about 19,800 miles, above Earth’s surface. That distance puts it just inside the altitude band where geosynchronous satellites orbit, roughly 35,800 kilometers up, meaning Apophis will thread a path below some of the communications and weather satellites that ring the planet in fixed positions relative to the ground. NASA’s own asteroid science page describes the flyby as coming closer than many operational satellites, a detail that has made the 2029 approach one of the most anticipated near-Earth object events in decades, according to the agency’s overview of Apophis and its orbital history.

Why the impact risk was ruled out

Apophis briefly topped the Torino Scale, the tool astronomers use to communicate asteroid risk to the public, after its discovery raised concerns about a possible 2029 impact. Additional radar and optical observations through the following years progressively tightened the uncertainty in its orbit until scientists could rule out any impact risk for 2029, a subsequent 2036 pass, and, following a 2021 update incorporating further radar data, effectively rule out an impact for at least the next hundred years. That refinement process is documented in detail on the Wikipedia entry tracking Apophis’s discovery and orbital determination, which lays out how each observation campaign narrowed the range of possible future paths.

The discovery that briefly topped the asteroid risk scale

Apophis first entered the record books on June 19, 2004, when astronomers Roy Tucker, David Tholen, and Fabrizio Bernardi spotted it using a telescope at Kitt Peak National Observatory in Arizona. The Torino Scale that the asteroid briefly topped a few months later is a ten-point system developed by MIT planetary scientist Richard Binzel, combining an object’s impact probability with the kinetic energy it would release to translate dense orbital statistics into a single number that non-specialists could interpret at a glance. Apophis reached level 4, still the highest rating any asteroid has ever been assigned, before additional radar and optical observations extended the tracked arc of its orbit enough to rule out the impact entirely within weeks. That episode has since become a reference case cited whenever a newly discovered object briefly spikes in apparent risk before more data arrives, a pattern that has repeated with smaller near-Earth objects many times since 2004.

Two spacecraft will meet Apophis during the flyby

Rather than simply watching from Earth, both NASA and the European Space Agency are sending hardware to the encounter. NASA redirected its OSIRIS-REx spacecraft, fresh from its Bennu sample-return mission, into a new mission called OSIRIS-APEX to rendezvous with Apophis and study how the close Earth passage affects the asteroid’s spin, surface, and orbit. ESA is preparing a dedicated mission called Ramses, short for Rapid Apophis Mission for Space Safety, intended to arrive in orbit around Apophis in February 2029, roughly two months before the flyby, so instruments are already in place when Earth’s gravity begins reshaping the asteroid’s surface. Details on that mission are outlined on the European Space Agency’s planetary defense page for Apophis.

What Earth’s gravity might do to the asteroid itself

Part of the scientific interest in Apophis has nothing to do with risk to Earth and everything to do with what Earth might do to Apophis. A close gravitational encounter of this magnitude can trigger measurable changes in an asteroid’s rotation rate, and potentially trigger landslides or other surface disturbances as tidal forces flex the body. Scientists studying rubble-pile asteroids, loosely bound collections of rock and dust rather than solid stone, see the 2029 flyby as a rare natural experiment: a controlled, predictable close encounter that will let instruments already in place measure exactly how a planet’s gravity reshapes a small world in real time.

A visible flyby for a large share of the world’s population

Because Apophis will pass so close and so fast, it will briefly become visible to the naked eye from parts of Europe, Africa, and Asia as it crosses the sky in a matter of hours, moving faster than typical satellites due to its proximity. Estimates suggest that up to 90 percent of the world’s population could be positioned to see it under the right viewing conditions, weather and light pollution permitting, making the 2029 approach as much a shared public spectacle as a scientific one. For researchers, the event offers a once-in-a-generation chance to study a near-Earth asteroid up close during exactly the kind of gravitational interaction that shapes how these objects evolve over millions of years, without any of the risk that made Apophis notorious in the first place.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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