Apophis, a massive asteroid named after the Egyptian “god of chaos,” has been drawing attention since its discovery in 2004. New analyses suggest that the risk of it hitting Earth may be higher than previously believed. While the asteroid is expected to pass close by in 2029, the possibility of external factors altering its trajectory raises concerns for future encounters.
Discovery and Initial Concerns
Apophis was initially placed at level 4 on the Torino Impact Hazard Scale, a system that assesses the potential danger of Near-Earth Objects (NEOs). A level 4 rating means a close encounter requiring attention, though not necessarily a guaranteed impact. Apophis was the first asteroid ever assigned this level, sparking interest and concern from astronomers worldwide.
NASA has closely monitored Apophis since its discovery. Initially, projections showed no significant threat from the asteroid in its close approaches in 2029, 2036, or 2068. However, recent studies have introduced the idea that a collision with another object in space could change Apophis’s path, possibly putting it on a dangerous course toward Earth.
The New Study: Could Apophis’ Trajectory Change?
Canadian astronomer Paul Wiegert, along with co-author Ben Hyatt, examined the odds of an external collision altering Apophis’s trajectory. Their study focused on the potential for a small object to collide with Apophis before its 2029 flyby, setting it on a trajectory that could lead to an Earth impact in the future.
Their research found that an impactor as small as 0.6 meters (2 feet) in diameter could push Apophis into one of the “keyhole” trajectories in 2029. These keyholes are gravitational regions that could redirect the asteroid toward Earth on a later pass. However, for an immediate collision to occur in 2029, a larger object—around 3.4 meters (11.2 feet) in diameter—would need to hit Apophis.
How Likely Is a Collision?
The probability of such a collision is extremely low. Wiegert’s study suggests the odds of an asteroid deflecting Apophis into an Earth-bound trajectory in 2029 are about one in 2 billion. The chance of an impact after 2029 is similarly slim, estimated at less than one in a million. Despite these favorable odds, the risk of an impact cannot be entirely ruled out, especially if unforeseen events alter the asteroid’s path.
Monitoring Apophis: The Waiting Game
Monitoring Apophis has been limited since May 2021 due to its positioning in the sky. The asteroid will remain largely unobservable until 2027 because it is currently located in the daytime sky relative to Earth and the Sun. As a result, astronomers will have to wait another three years to gather more data and assess any changes in its trajectory.
Conclusion: Apophis and the Future
Although current observations suggest that Apophis will safely pass Earth in 2029, the potential for a trajectory change adds an element of uncertainty. The odds of an impact remain minimal, but astronomers will continue to monitor the asteroid closely in the years leading up to its flyby. Advances in technology and continued observation will be crucial in determining whether Apophis poses a future threat to our planet.
