As of April 13, the Apophis asteroid is now less than three years away from making a close approach with Earth in 2029.
As of April 13, an infamous giant asteroid known as Apophis is now three years away from becoming the first space rock of its size to come near Earth in recorded human history.
Roughly the size of five NFL football fields, Apophis made a name for itself more than two decades ago when its discovery accompanied the terrifying revelation that it had a non-zero chance of hitting Earth in 2029. While that risk of impact has been confidently ruled out, the date of its future rendezvous with our planet on Friday the 13th is likely no salve to those who are superstitious.
But for the less-superstitious and more scientific-minded folks, Apophis’ impending approach toward our planet represents an unprecedented opportunity to study one of the most potentially hazardous asteroids ever detected. In 2029, its orbit will bring Apophis closer than the distance of many telecommunications satellites in geosynchronous orbit, which matches Earth’s 24-hour rotation.
A collision with Earth would have been devastating. A harmless encounter that close, on the other hand, could lead to a cosmic breakthrough in humanity’s understanding of near-Earth asteroids.
Now that Apophis is less than three years away from passing near Earth, here’s everything to know about the asteroid.
What is the Apophis asteroid?
Apophis is the name of a giant asteroid that was first discovered in 2004 by astronomers at the Kitt Peak National Observatory in Tucson, Arizona.
A relic of the early solar system, Apophis is an ancient space rock that originated in the main asteroid belt between Mars and Jupiter, according to NASA. For millions of years, it was altered by the gravitational influence of large planets such as Jupiter so that it is now much closer to Earth in its orbit of the sun.
It’s now classified as a near-Earth asteroid rather than a main belt asteroid.
How big is Apophis?
NASA compares the size of Apophis, which is about a quarter of a mile long, to the Eiffel Tower in France.
While the exact shape of Apophis remains a mystery, radar observations suggest it is an elongated peanut shape.
What was Apophis the god of? What is 99942?
Apophis is named for an ancient god in Greek mythology for the sheer devastation its impact with Earth would bring.
The team of astronomers credited for Apophis’ discovery – David Tholen, Fabrizio Bernardi and the late Roy Tucker – were also responsible for coming up with the asteroid’s ominous name. Apophis is the Greek name for Apep, the ancient Egyptian god of evil and destruction.
But before Apophis attained its infamous moniker, it was dubbed the less-exciting 2004 MN4 by the International Astronomical Union (IAU). The asteroid was later assigned asteroid number 99942 by the Minor Planet Center – the official authority for observing and reporting new asteroids, comets and other small bodies in the solar system.
Asteroid Apophis to make close approach to Earth in 2029
Apophis and Earth, each following its own orbit around the sun, will pass each other on April 13, 2029.
Apophis will pass Earth again March 30, 2036, though at a much farther distance of 5.2 million miles – or 20 times the distance between the Earth and moon, according to the Planetary Society.
Could Apophis hit Earth in 2029 or 2036? No risk of impact
When Apophis was first spotted, it appeared the asteroid had a slight chance of hitting Earth in the coming decades, including 2029 and 2036.
But after further observations of its orbit, astronomers were able to rule out a risk of Apophis crashing into Earth for at least a century, according to NASA.
What would happen if Apophis hit Earth?
Though not as big or catastrophic as the asteroid theorized to have wiped out the dinosaurs 66 million years ago, Apophis would cause widespread destruction up to several hundred kilometers from its impact site.
The energy released would equal more than 1,000 megatons of TNT, or tens to hundreds of nuclear weapons, according to the Planetary Society, a nonprofit organization promoting space exploration.
How close will Apophis come to Earth?
In less than three years, Apophis’ orbit will bring it just 20,000 miles from Earth, the closest any large asteroid has ever come to our planet that scientists have known about in advance, according to NASA.
The asteroid poses no danger to our planet, nor is it a threat to satellites and the astronauts aboard the International Space Station orbiting Earth much closer to our atmosphere.
But the flyby poses a “totally unprecedented” opportunity for scientists to observe and learn much more about Apophis and similar near-Earth asteroids, NASA explains.
What will Apophis look like from Earth?
Apophis will be visible to observers on the ground in the Eastern Hemisphere, including Europe, Africa and western Asia. What’s more, you won’t even need a telescope or binoculars to see it, as it will be large and close enough to be seen with the unaided eye.
At the projected distance and brightness, Apophis should look to the naked eye like a bright star moving across the sky, according to the Planetary Society.
NASA, ESA race to study Apophis
In the coming years, NASA and the European Space Agency plan to take advantage of the rare flyby by sending uncrewed spacecraft to observe Apophis.
NASA’s OSIRIS-REx, which gathered and returned a sample of asteroid Bennu in September 2023, has been renamed OSIRIS-APophis EXplorer (OSIRIS-APEX) and sent on a trajectory that would allow it to cross paths with the asteroid in 2029. Though it will not collect samples this time around, OSIRIS-APEX will reach Apophis in June that year for an 18-month campaign that involves firing its engines to kick up loose rocks and dust to offer a peek at the material just below the surface.
The ESA plans to launch a spacecraft of its own called Ramses, which must be ready to launch a year ahead of time to meet Apophis before it passes by Earth. During that time, the mission will observe how the surface of the asteroid changes from being in such close proximity to Earth, the agency has previously said.
Could we stop an asteroid like Apophis?
Should any asteroids pose a serious threat to Earth, NASA and the world’s space agencies have had a planetary defense strategy in place for years against dangerous space rocks.
In 2022, for example, NASA’s Double Asteroid Redirection Test (DART) demonstrated that it was possible to nudge an incoming asteroid out of harm’s way by slamming a spacecraft into one intentionally. While the small moonlet asteroid Dimorphos posed no threat to Earth, the mission served as a successful demonstration that dangerous space rocks could be diverted from a collision course with Earth.
Recently, new research revealed that the mission not only altered the orbit of Dimorphos, but the larger near-Earth asteroid it orbits, named Didymos.
The ESA’s Hera spacecraft remains on its way to study the remnants of the impact even further.
Eric Lagatta is the Space Connect reporter for the USA TODAY Network. Reach him at [email protected]
