On April 13, 2029, the asteroid Apophis will make a remarkably close approach to Earth, offering a unique opportunity for both scientific observation and public spectacle. For the first time in history, a potentially hazardous asteroid will be visible to the naked eye, a sight that will be easily observable across Africa and Western Europe under clear skies. Its brightness will be comparable to the stars in the Big Dipper.
This event is momentous. Richard Binzel, a professor of planetary sciences at MIT, emphasizes the significance, stating that a close approach by an asteroid of this size (approximately 1,100 feet or 340 meters across) is an exceptionally rare occurrence, estimated to happen only once every 7,500 years. While the public can anticipate a dazzling celestial display, scientists see an unparalleled opportunity: a real-time, large-scale experiment to study the effects of Earth's gravity on a massive asteroid. The interaction's impact on Apophis' orbit and rotation remains unknown, highlighting the need for direct observation.
The initial discovery of Apophis in 2004 sparked concerns, with early calculations suggesting a small but non-negligible chance of impact. This led to its designation as a potentially hazardous asteroid and earned it the nickname "god of chaos." However, years of meticulous tracking and radar observations have dramatically refined its predicted trajectory, removing it from all risk lists. While a minuscule possibility of a collision remains (odds exceeding one in a billion), scientists confidently assert that Apophis poses no threat for at least the next century.
The upcoming flyby presents an invaluable opportunity for planetary defense research. The close approach, closer than geostationary satellites, will alter Apophis' orbit, shifting it from an Aten-class to an Apollo-class trajectory. NASA's repurposed OSIRIS-REx spacecraft (now OSIRIS-APEX) will play a crucial role, mapping the asteroid's surface, monitoring its spin, and potentially measuring seismic vibrations within Apophis—a feat only previously achieved with the Moon and Mars. Furthermore, the European Space Agency's RAMSES mission, pending approval, aims to conduct close-range observations before, during, and after the flyby, possibly even deploying a cubesat to detect seismic waves.
Apophis, therefore, serves as more than just a spectacle; it's a critical testing ground for planetary defense strategies. By studying the effects of Earth's gravity on this asteroid, scientists can refine models crucial for deflecting future hazardous asteroids. While Apophis itself poses no immediate danger, it provides an invaluable opportunity to enhance our understanding and preparedness for potential future threats, underscoring the importance of continuous research and observation in this field. The event is a powerful reminder of the dynamic nature of our solar system and the importance of scientific curiosity in understanding and mitigating potential risks.
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Originally published at: https://www.livescience.com/space/asteroids/apophis-flyby-in-2029-will-be-the-first-time-a-potentially-hazardous-asteroid-has-been-visible-to-the-naked-eye
