We’re Safe from Apophis for at Least Another Century (and Probably Long After, Too)

Radar observations of asteroid 99942 Apophis made with the DSN Goldstone and NSF Green Bank Telescope facilities on March 8, 9, and 10, 2021 at a distance of about 10.6 million miles…about 44 times the distance to the Moon. Credits:  NASA/JPL-Caltech and NSF/AUI/GBO.

If you’ve ever had concerns or even a passing curiosity about an asteroid named Apophis slamming into Earth in the near future, causing widespread death and destruction and/or even bringing about the demise of civilization as we know it, you can safely jettison all of them into a safe solar parking orbit. Not only will the 1100-foot/340-meter-wide near-Earth object 99942 Apophis assuredly not be impacting Earth in 2029 nor in 2068 (which at one time there was suggested there was a minuscule but still non-zero chance of) but, thanks to radar observations made during a near-ish pass in March 2021 we can now say there are no chances of an Apophis impact as far out as at least 100 years.

(Whether you find that news highly relieving or disappointing is entirely subjective.)

“With the support of recent optical observations and additional radar observations, the uncertainty in Apophis’ orbit has collapsed from hundreds of kilometers to just a handful of kilometers when projected to 2029. This greatly improved knowledge of its position in 2029 provides more certainty of its future motion, so we can now remove Apophis from the risk list.”

– Davide Farnocchia, NASA’s Center for Near-Earth Object Studies (CNEOS)

According to a March 25 news release from NASA’s Jet Propulsion Laboratory (which manages CNEOS):

Estimated to be about 1,100 feet (340 meters) across, Apophis quickly gained notoriety as an asteroid that could pose a serious threat to Earth when astronomers predicted that it would come uncomfortably close in 2029. Thanks to additional observations of the near-Earth object (NEO), the risk of an impact in 2029 was later ruled out, as was the potential impact risk posed by another close approach in 2036. Until this month, however, a small chance of impact in 2068 still remained.

When Apophis made a distant flyby of Earth around March 5, astronomers took the opportunity to use powerful radar observations to refine the estimate of its orbit around the Sun with extreme precision, enabling them to confidently rule out any impact risk in 2068 and long after.

Apophis’ 2029 pass by Earth should still be a good show though, even sans catastrophe.

On April 13, 2029, the asteroid Apophis will pass less than 20,000 miles (32,000 kilometers) from our planet’s surface – closer than the distance of geosynchronous satellites. During that 2029 close approach, Apophis will be visible to observers on the ground in the Eastern Hemisphere without the aid of a telescope or binoculars. It’s also an unprecedented opportunity for astronomers to get a close-up view of a solar system relic that is now just a scientific curiosity and not an immediate hazard to our planet. (Source)

The animation below depicts the orbital trajectory of asteroid 99942 Apophis as it passes safely by Earth on April 13, 2029. Earth’s gravity will slightly deflect its trajectory as Apophis comes within 32,000 km (20,000 miles) of Earth’s surface.

So as the 2020s near their end it’s possible you may still see some ill-intended news stories breathlessly describing a fearsome impact event (and to be fair, a direct hit from a thousand-foot-wide asteroid—especially in a populated area—would definitely leave a mark) so try to file this away in your mind palace: we’re firmly safe from Apophis. For the foreseeable future anyway.

Now as far as Bennu in September 2182 is concerned…well, that’s another story.

You can see more news and data from NASA’s Center for Near-Earth Object Studies here.

One Comment

  1. gregdougall says:

    I disagree.

    Liked by 1 person

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