The asteroid Apophis, measuring approximately the size of the Eiffel Tower, is expected to make an unusually close approach to Earth in 2029. According to NASA, the asteroid will pass approximately 20,000 miles from the Earth's surface on April 13, 2029, a distance closer than many satellites in orbit.
Apophis is classified as "potentially hazardous" and is composed of leftover "raw material" that was never part of a planet or moon. Initially, astronomers thought Apophis might impact Earth in either 2029, 2036, or 2068, but further observations have revealed that there is no risk of impact for at least 100 years.
The asteroid was discovered on June 19, 2004, by astronomers at Kitt Peak National Observatory in Arizona. Due to technical and weather issues, they were only able to observe Apophis for two days. A team of astronomers in Australia was able to make further observations in December 2004, providing valuable data on the asteroid's orbit.
To better understand Apophis' physical properties, observatories around the world and in space will observe its historic close approach. In anticipation of the event, NASA has redirected a spacecraft to rendezvous with Apophis shortly after its 2029 Earth close-approach.
The European Space Agency is also sending a spacecraft to study the asteroid. Apophis is expected to be visible to observers in the Eastern Hemisphere, weather permitting, without the need for a telescope or binoculars.
The close approach will have a significant effect on Apophis' orbit, with the asteroid being pulled, twisted, stretched, and squeezed by the Earth's gravity. This will change Apophis' orbit around the Sun, making it slightly larger and giving it a longer orbital period.
