‘Earth Impact’ Risk Asteroid Apophis Passed By Five Days Ago

Apophis. Photo by Korea Astronomy and Space Science Institute

[Asia Economy Reporter Kim Bong-su] The asteroid Apophis, measuring 370 meters in diameter, approached Earth to within approximately 16.8 million kilometers at 10:15 a.m. on the 6th (Korean Standard Time) and passed near Earth at a speed of 4.58 km per second. Since its discovery in 2004, Apophis has consistently been considered a potential threat of collision with Earth.

The Korea Astronomy and Space Science Institute (KASI) announced on the 11th that since February, when Apophis began approaching Earth, they have been tracking and observing it using the Optical Wide-field patroL Network (OWL-Net) electronic optical surveillance system for space objects, and released observation footage. This footage was captured on the 10th by OWL-Net Unit 4 located at the Lemon Mountain Observatory in Arizona, USA. KASI stated, "For this Apophis observation, we have organized an international joint observation network with over 30 observatories worldwide to lead asteroid tracking and characteristic analysis research projects."

After this approach, Apophis is expected to pass very close to Earth again on April 14, 2029, at 6:46 a.m. The distance from Earth at that time will be about 37,000 kilometers. This means Apophis will be approximately 4,000 kilometers closer to Earth than geostationary satellites such as Chollian and Mugunghwa. The probability of an asteroid the size of Apophis approaching this close to Earth is about once every 1,000 years.

The asteroid Apophis was first discovered on June 19, 2004, by Roy A. Tucker, David J. Tholen, and Fabrizio Bernardi at the Kitt Peak Observatory under the National Optical Astronomy Observatory in the United States. Immediately after its discovery, the International Astronomical Union (IAU) Minor Planet Center (MPC) assigned it the provisional designation '2004 MN4,' and on June 24, 2005, it was given the permanent number '99942.' Later, on July 19 of the same year, it was officially named 'Apophis.' The name Apophis is the Greek transliteration of 'Apep,' the giant serpent god of destruction in Egyptian mythology who swallowed the sun god Ra.

OWL-Net No.4 (USA), monitoring space objects around the Earth. Photo by Korea Astronomy and Space Science Institute

Since its discovery, Apophis has consistently been considered a potential collision threat to Earth. It was the first asteroid to receive a Torino scale rating of '4.' The Torino scale ranges from 0 to 10 and indicates the probability of a near-Earth object colliding with Earth and the predicted damage if a collision occurs; higher numbers indicate greater risk.

According to NASA's Jet Propulsion Laboratory (JPL), Apophis is one of four potentially hazardous asteroids with a collision probability with Earth within 100 years higher than one in a million. Among these four hazardous asteroids is Bennu, which NASA's OSIRIS-REx spacecraft successfully landed on in October 2020 to collect soil samples after its launch in 2016. The updated collision probability for Apophis in April 2068 is 0.00026% (1 in 380,000), as of January 20.

The fact that an asteroid approaches Earth means that with relatively little fuel, a spacecraft can reach the asteroid, making it an excellent target for exploration. Assuming spacecraft launches between 2025 and 2030, among over 2,000 potentially hazardous asteroids, Apophis is the only one requiring a delta-v (velocity increment) of less than 6 kilometers per second. The Korea Astronomy and Space Science Institute is conducting preliminary mission studies aiming for a direct rendezvous mission with Apophis in 2029.

This content was produced with the assistance of AI translation services.