Increased Risk: Apophis Asteroid May Hit Earth

An astrophysicist at the University of Western Ontario has found that the probability of asteroid 99942 Apophis colliding with Earth might be marginally higher than previously believed. In a recent study published in The Planetary Science Journal, Paul Wiegert explored a new angle: the impact of a smaller asteroid on Apophis's trajectory, potentially altering its path towards Earth.

Apophis was first identified in 2004 and initially earned a high rating of 4 on the Torino impact hazard scale due to its potential threat. Despite this, the asteroid’s risk level was considered low enough that it was merely classified as one to monitor. Apophis is expected to make close approaches to Earth in 2029, followed by additional passes in 2036 and 2068.

In his latest research, Wiegert examined how a smaller celestial body hitting Apophis might affect its orbit. He found that even an asteroid as small as 0.6 meters in diameter could potentially change Apophis’s course. More significantly, an object around 3.4 meters wide could potentially redirect Apophis into a collision path with Earth by 2029.

To estimate the likelihood of such a scenario, Wiegert analyzed the frequency of similar-sized objects hitting Earth. His calculations suggest the probability of a 3.4-meter object impacting Apophis is about 1 in 100 million. Furthermore, considering the precise conditions required for such an impact, he estimates the chance of it leading to a collision with Earth is around 1 in 2 billion, with the overall risk of a future impact at about 1 in 1 million.