During its 2029 close approach to Earth, Asteroid Apophis will endure seismic activities and surface modifications.
A group of celestial explorers presume that our world's gravitational pull might manipulate the landscape of Apophis, a nearby Earth asteroid (NEA) anticipated to approach our planet in five years.
At present, Apophis is 1.97 astronomical units distant from Earth, which is about twice the distance between our planet and the Sun. In April 2029, however, the asteroid will hurtle past our planet, leading a set of professionals to propose that this interaction will trigger landslides and tremors on the smaller celestial body. Their findings are to be published in The Planetary Science Journal and are presently available on the preprint server arXiv.
As expressed in the paper, the 2029 rendezvous will induce temporary tidally-driven seismic occurrences generating high-frequency surface accelerations that reach magnitudes similar to Apophis' gravitational pull, potentially detectable by modern seismometers.
Space experts are monitoring Apophis' April 13, 2029 flyby attentively—and yes, this occurs on a Friday. At its closest approach, the 1,100-foot-wide (335-meter-wide) asteroid will be approximately 24,000 miles (38,625 kilometers) from Earth's surface, which is roughly ten times further than the Moon's ordinary distance during its orbit.
The proximity of Earth means that Apophis will be impacted by our planet's gravitational pull, the same force keeping the Moon in orbit around us. However, Apophis is significantly smaller than the Moon and will be closer to Earth, causing Earth's gravity to have a more dramatic impact on the asteroid. This is the same force responsible for producing stress and fracture marks on the surfaces of moons like Uranus' Miranda, and has led to concerns about the Moon's stability, impairing NASA's ability to securely land astronauts during the upcoming Artemis 3 mission.
"We also found that there will be a significant shift in Apophis' spinning tumble that may lead to longer-term surface renovation as a consequence of rolling-induced surface slope adjustments," the team wrote, suggesting that this mechanism could revitalize the surfaces of other asteroids like Apophis.
This discovery is intriguing because scientists can glean lots of information from asteroid interiors. These hidden asteroid components offer clues about the origins of space rocks and can also shed light on the history of our solar system and beyond. Organic molecules in asteroids may hint at sources of life's building blocks, while the metals in the rocks reveal the extreme cosmic interactions responsible for the asteroid's formation. Asteroid interiors hold layers of ancient information regarding the contents of a space rock and its interactions inside its local environment, and may clarify why certain objects—such as the peculiar interstellar interloper 'Oumuamua—accelerate like spaceships.
Similar to 'Oumuamua, Apophis is expected to make a flyby around Earth. Although Apophis poses almost no threat to life on Earth, an event where its trajectory significantly altered, putting it on a collision course with our planet, would require an extraordinary sequence of events to occur.
With that being said, objects similar in size to Apophis collide with our planet once every 80,000 years, yielding devastating consequences in their immediate vicinity and potentially causing significant climate changes. A NASA analysis conducted in 2021 confirmed that Apophis' trajectory doesn't pose a threat to our planet—meaning not even the slightest chance of harm—for at least a century.
Earlier this year, space enterprises such as Blue Origin proposed missions to take advantage of Apophis' proximity to Earth. After all, space agencies are essentially cosmic doctors making house calls, and it is significantly more cost-effective when the patient comes to you.
However, forget about mission proposals for the moment—the NASA OSIRIS-APEX mission is already en route towards the asteroid to gain a better understanding of how the rock may change following its close encounter with our planet.
If it were to collide with Earth—which it won't—Apophis' impact footprint would neatly encompass Manhattan's Battery Park. The last substantial asteroid to impact Earth was the Chelyabinsk fireball—a rock about the size of a small building that exploded over Russia in 2013. The explosion released energy equivalent to approximately 500 kilotons of TNT, resulting in a brilliant flash and a powerful shockwave. The Chelyabinsk asteroid was less than 66 feet across (20 meters)—around 17 times smaller than Apophis.
Despite this, the comparison highlights the potential dangers posed by near-Earth asteroids, and the reason why agencies like NASA scrutinize them so closely. Indeed, by this team's calculation, Earth is set to inflict far more destruction on Apophis than the asteroid might inflict on our planet.
The celestial event in 2029 presents an opportunity for scientists to study the impact of Earth's gravity on Apophis, as advancements in technology and space exploration allow for closer observation and analysis. In the future, understanding such interactions could lead to advances in predicting and mitigating potential risks from near-Earth asteroids, leveraging the knowledge gained from Apophis for the benefit of space science and planetary defense.
