Set your calendars for April 13, 2029 when a speck of light will streak across the sky, getting brighter and faster as Apophis (near-Earth asteroid 99942) cruises harmlessly past our planet.
This 1,100 foot-wide (340 meters) space rock will come within 19,000 miles (31,000 km) of Earth gaining in brightness equal to that of the stars in the Little Dipper.
Discovered in June 2004 by a team of astronomers at the Kitt Peak National Observatory, the asteroid was only able to be detected for about two days before weather and technical issues prevented further study. Initial calculations revealed that the asteroid had a 2.7% chance of impacting with Earth in 2029.
Luckily, another team rediscovered the asteroid at the Siding Springs Survey in Australia later that same year. Additional observations of Apophis have completely ruled out the possibility of collision.
Apophis will first become visible to the naked eye in the night sky over the Southern Hemisphere, on an East to West trajectory. At this time, it will be mid-morning on the east coast of the United States.
By mid-afternoon EST, the asteroid will be above the African continent, still traveling West.
Around 6pm EST, Apophis will be over the Atlantic Ocean and will be moving so fast that it will cross the ocean’s entirety within one hour. Sky watchers here in the US should expect to see it around 7pm EST as it crosses the United States.
The international asteroid research community couldn’t be more excited about this rare event.
In fact, today, April 30th, at the 2019 Planetary Defense Conference in College Park, Maryland, scientists have gathered discuss plans for observation of, as well as hypothetical missions we could send out to the asteroid in order to further study it.
“The Apophis close approach in 2029 will be an incredible opportunity for science,” says Marina Brozovi, a radar scientist at NASA’s JPL in Pasadena, 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.”
Ever since its initial discovery, optical and radar telescopes have been tracking Apophis as it continues to orbit the Sun.
This means that scientists know its future trajectory quite well.
While current calculations show that the asteroid still has a small chance of impacting Earth (less than 1 in 100,000) many decades from now, scientists are certain that future measurements of its position, especially those made during the 2029 flyby, will rule out any possible impacts.
“Apophis is a representative of about 2,000 currently known Potentially Hazardous Asteroids (PHAs),” says 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.”