Among the few near-Earth objects posing potential risks, asteroid Apophis stands out. Recent analyses by NASA scientists indicate a very low but possible chance of impact in 2068—requiring extraordinarily bad luck.
On April 13, 2029, this 340-meter-wide asteroid will safely pass Earth at about 31,000 km—astronomically close, compared to the Moon's average distance of 384,000 km. Named after the Egyptian god of chaos, Apophis offers a rare scientific opportunity.
“The 2029 close approach will be an unprecedented chance for science,” says Marina Brozović of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “We’ll use optical telescopes and radar to observe surface details as small as a few meters.”
Visible to the naked eye from Australia that morning, Apophis will traverse the Indian Ocean, Africa, the Atlantic, and reach the U.S. West Coast. But today’s focus is on 2068.
Early 2023 observations from Hawaii’s Subaru telescope refined our understanding of the Yarkovsky effect on Apophis’ orbit, allowing better risk assessment for its 2068 return.
The Yarkovsky effect arises as an asteroid rotates around the Sun: one side absorbs more sunlight, heating up and re-radiating photons, creating tiny thrust that accumulates over time. This must be factored into long-term predictions.
“Without Yarkovsky drift, Apophis poses no 2068 threat,” explains Dave Tholen, astronomer at the University of Hawaii’s Institute for Astronomy. “Accounting for it keeps the impact scenario alive—odds are slim, but greater than zero.”
Current calculations peg the 2068 impact probability at 1 in 530,000 on April 13. Estimates will evolve with ongoing observations. A strike could release energy equivalent to 1,151 megatons of TNT, causing widespread devastation.
Apophis ranks third on NASA’s Sentry Risk Table. Ahead are 29075 (1950 DA) with 1-in-8,300 odds in 2880, and Bennu (recently sampled by OSIRIS-REx) at 1-in-2,700 between 2175 and 2199.
