A new prediction reveals that the asteroid Apophis, ominously known as the "God of Chaos," could undergo violent tremors when it makes an exceptionally close approach to Earth in five years. Named after the Egyptian deity of chaos, Apophis is expected to pass within 19,000 miles of our planet on April 13, 2029, close enough for Earth's gravity to exert a significant effect.
Gravitational Forces Could Cause 'Astroquakes'
Researchers predict that Earth's gravity could unleash powerful "astroquakes" on Apophis, shaking the asteroid violently. These tremors are thought to be triggered by gravitational tidal forces, which arise from the uneven pull exerted by a massive body, such as Earth, on a nearby object. Ronald-Louis Ballouz, an asteroid scientist at the Johns Hopkins University Applied Physics Laboratory, led the research team in creating computational models to simulate Apophis's interaction with Earth's gravitational field.
The team identified two distinct processes that could alter Apophis's surface. The first involves throwing rocks and dust from the asteroid's surface, potentially sending debris into space. The second, more gradual process could trigger landslides over tens of thousands of years, reshaping the asteroid's structure. Both phenomena could refresh the 4-billion-year-old asteroid's surface and reveal underlying layers.
Apophis: A 'City-Killer' Asteroid
Apophis, roughly the size of the Empire State Building, is classified as a "city-killer" asteroid. If it were ever to strike Earth, the impact would be equivalent to detonating tens or even hundreds of nuclear bombs, capable of annihilating an entire city and spreading destruction over a radius of hundreds of miles. The asteroid's path has been closely monitored since its discovery in 2004 when initial estimates suggested a 2.7 percent chance of a collision in 2029. Thankfully, more recent analyses have dramatically reduced those odds to one in two billion, securing our safety for at least the next century.
Aside from the immediate shaking, Earth's gravity could also disrupt Apophis's tumbling motion. Unlike planets that rotate smoothly on an axis, asteroids like Apophis tumble erratically. This disruption may result in surface landslides over millennia, gradually reshaping the asteroid. Ballouz and his team speculate that these gravitational interactions could explain why some asteroids lack the typical space-weathered surfaces seen on others that have not passed close to planets, Live Science reports.
Upcoming NASA Mission to Study Apophis
To investigate these predictions, NASA's OSIRIS-APEX mission will rendezvous with Apophis during its flyby and study the asteroid for 18 months. This extended observation period will help scientists document any physical changes caused by the close encounter and provide insights into how Earth's gravity affects near-Earth objects.
While Apophis poses no threat for the foreseeable future, the Planetary Society and NASA's Planetary Defense Coordination Office are developing strategies to protect Earth from potential asteroid impacts. Efforts include deflection missions and research into ways to neutralize threats from other 'city-killer' asteroids. Despite the relative safety of Apophis, these initiatives underscore the importance of preparedness in case another hazardous space rock comes our way.
The full research findings are available on the arXiv preprint database and will be published in the Planetary Science Journal. Until 2029, scientists will continue monitoring Apophis as it approaches, offering valuable lessons about gravitational interactions and planetary defense strategies.
