First spotted back in 20014 at Kitt Peak National Observatory, astronomers at the time gave the asteroid a level 4 on the Torino Scale, the highest ever assignment for a near-Earth object. Researchers gave it a 2.7 percent chance that it would hit Earth.
Since then the asteroid has been downgraded and astronomers are confident it won’t make an impact with Earth, but it will still come pretty darn close. Scientists at NASA’s Jet Propulsion Laboratory are preparing for the passing of 99942 Apophis, even though it won’t happen for a decade.
Mark your diary
99942 Apophis is set to cruise past Earth on April 13, 2029, at its closest point it will just be 1,000 kilometers above the surface of our planet. That’s about the same distance as some spacecraft orbit the earth at.
While posing no danger, this closeness is a big opportunity for asteroid scientists to examine a space rock in its natural habitat.
"The Apophis close approach in 2029 will be an incredible opportunity for science," said Marina Brozović, a radar scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, who works on radar observations of near-Earth objects (NEOs).
"We'll observe the asteroid with both optical and radar telescopes. With radar observations, we might be able to see surface details that are only a few meters in size."
The rare event gets the science world pumped
At 340-meter-wide, the asteroid is a rare event. Rarely do asteroids of this size pass so close by. If you are around in April in a decades time, the asteroid will even be able to see by the naked eye.
Observers will see a moving point of light, the first to spot it will be those located on the East coast of Australia, it will travel west across the Indian Ocean, then across Africa.
It will be at its closest point just before 6 p.m. EDT, Apophis will be over the Atlantic Ocean. It is moving so fast that it can cross the Atlantic in about an hour.
Scientists came together this week at the Planetary Defense Conference to discuss strategies for tracking and analyzing Apophis as it passes by.
Planetary defense tactics boosted by flyby
“We already know that the close encounter with Earth will change Apophis' orbit, but our models also show the close approach could change the way this asteroid spins, and it is possible that there will be some surface changes, like small avalanches," said Davide Farnocchia, an astronomer at JPL's Center for Near Earth Objects Studies (CNEOS), who is co-chaired the April 30 conference session on Apophis with Brozović.
Apophis is a representative of about 2,000 currently known Potentially Hazardous Asteroids (PHAs)," said Paul Chodas, director of CNEOS.
"By observing Apophis during its 2029 flyby, we will gain important scientific knowledge that could one day be used for planetary defense."