The asteroid Apophis, also known as 99942 Apophis, will have its historic close approach to Earth on Friday, the 13th of April 2029. With its diameter at approximately 375 meters, this NEA will be reaching Earth at a distance of about 32,000 kilometres, just over a tenth of the distance to the Moon. Initial estimates sparked fears over the possibility of a collision with Earth, and the fear of a doomsday impact spread worldwide. But years of detailed observations were followed by a battery of sophisticated computer simulations, confirming that Apophis posed no threat to Earth for at least the next 100 years. Although this encounter is perfectly harmless, it offers a great opportunity to observe and study in unprecedented detail an asteroid that is the size of a large building.
NASA confirms: Apophis’ discovery in 2004 and its rare, close flyby of Earth in 2029
Apophis was discovered in 2004 and gained notoriety from early calculations that showed a possibility of impact with Earth in 2029. Its size alone: larger than many urban blocks means a collision with Earth would have catastrophic consequences. This resulted in an unprecedented amount of media coverage and public interest in the asteroid. Over the years, extensive tracking of Apophis by astronomers around the world has been made possible by using optical telescopes and radar data, thus refining its orbital path. Scientists are now able to pinpoint with remarkable accuracy the trajectory of this asteroid and exclude any possibility of a near-term hazard.On 13th April 2029, Apophis will make an exceptionally close approach, passing only 32,000 kilometres from Earth. For perspective, this is just about 10 percent of the gap between Earth and the Moon. Such proximity of an NEO like Apophis is a very rare event-most of them occur once in several thousand years. Although the asteroid will come closer than geostationary satellites, it will not collide with our planet. The approach will offer a great opportunity for scientists to do certain studies on the composition, rotation, and trajectory of Apophis that will be subtly influenced by Earth’s gravity.
From doomsday predictions to scientific certainty and research opportunities
When first discovered, Apophis generated concern about a possible collision on April 13th, 2029. Subsequent research also identified the possibility of impact in 2036 and 2068. However, with continuous observation and the development of accurate simulations, it was confirmed by NASA’s Jet Propulsion Laboratory in March 2021 that the asteroid Apophis would not be a threat to Earth for at least the next century. Recent measurements using radar and optical have lessened orbital uncertainty from hundreds of kilometres to only a few, offering astronomers a lot of confidence about its trajectory.Although harmless, the close approach of Apophis in 2029 gives significant scientific value: a chance for astronomers to study its surface, composition, and test methods for planetary defence. The more that is understood about Apophis’ behaviour, the greater the understanding of NEAs, which are increasingly critical for general planning in planetary defence. It reflects how refinement in modern space observation networks has paid off, demonstrating how scientists track the paths of potentially hazardous objects with uncanny accuracy.
