The asteroid Apophis is set to fly past Earth in April 2029, potentially releasing energy equivalent to 30 times that of the Tsar Bomba nuclear bomb if a collision occurs.
Apophis will pass within 39,000 km of Earth’s surface, which is close to the altitude at which television satellites operate, according to the Russian Emergency Situations Ministry. This figure aligns closely with earlier calculations by the U.S. National Aeronautics and Space Administration (NASA). In March 2021, NASA ruled out the possibility of Apophis impacting Earth in 2068 and estimated that the object will pass within less than 32,000 km of our planet on April 13, 2029.
Simulation of Apophis flying towards Earth. (Photo: iStock)
With a diameter of about 340 km, Apophis, named after the ancient Egyptian deity symbolizing chaos, is one of the most dangerous asteroids that could collide with Earth. Astronomers at an observatory in the U.S. discovered Apophis in 2004. Researchers at the University of Hong Kong indicated that this asteroid is unlikely to collide with Chinese satellites or space stations or other objects in low Earth orbit in 2029.
“The risk of collision with any satellite is very small considering the size and relative speed compared to the volume of space,” said Quentin Parker, head of the Space Research Laboratory at the University of Hong Kong. “The International Space Station (ISS) and China’s Tiangong station operate at much lower orbits, less than 500 km.”
According to Parker, Apophis will pass closer than 10 times the distance to the Moon. He estimates that there are about 500 geostationary satellites operating beyond that distance. Apophis will be the largest asteroid, measuring 300 – 400 m, to fly close to Earth in history.
Lee Man-hoi, a planetary dynamics expert and head of the Earth Sciences Department at the University of Hong Kong, estimates that an asteroid of this size could impact Earth on average once every 100,000 years. NASA removed Apophis from its risk list after announcing calculation results in March 2021 and stated that Apophis presents a great opportunity for astronomers to closely observe a remnant of the Solar System.
Researchers at the Russian Emergency Situations Ministry estimate that if it were to collide with Earth, Apophis would release energy equivalent to 1,717 megatons, which is 30 times stronger than the Tsar Bomba, the largest nuclear bomb ever detonated by the Soviet Union in 1961. The impact force would cause a 6.5 magnitude earthquake within a 10 km radius with wind speeds of at least 790 m/s, according to Sputnik. For comparison, a tornado with wind speeds of about 90 m/s has been known to demolish even the sturdiest houses. According to Parker, any damage from a collision with Apophis would be severe, whether on land or at sea, potentially causing tsunamis.