Asteroid 99942 Apophis
On April 13, 2029, an asteroid named Apophis will safely pass close to the Earth and will come to within about 20,000 miles from the Earth’s surface. This will be a close encounter, closer to Earth than the belt of geosynchronous satellites. Apophis’ closest approach is less than one-tenth of the distance of the Moon.
Apophis is oblong, estimated to have dimensions of 450 meters (1480 ft) by 170 meters (560 ft).
Apophis shape model (based on light curve data) is by Josef Ďurech and Vojtěch Sidorin
NASA overview of Apophis is at science.nasa.gov/solar-system/asteroids/apophis/
Animation of Apophis encounter.
Imagine watching the night sky as you see a 3rd magnitude star-like object moving perceptibly across the sky in real time! People in Africa and southern Europe will have the good fortune to best witness this celestial close call.
This animation shows the Earth from the perspective of asteroid 99942 Apophis. Earth enlarges as Apophis approaches with a closest encounter at 21:45 UTC. Maximum brightness comes at 20:35 UTC.
Peak brightness and closest approach
Two of the key events of the encounter between Earth and Apophis are the moment of peak brightness (as seen from Earth) at 20:35 UTC and the moment of closest approach at 21:45 UTC at a height lower than geosynchronous satellites.
Hourly maps of Apophis visibility on Earth
You can use these maps to plan an observation campaign that optimizes the visible duration of the encounter, a good night sky during Apophis’ peak brightness and closest approach, and viewing Apophis at a high sky altitude. Click on any map to enlarge.
