Upcoming Close Encounters: Apophis and YR4 2024
In the coming seven years, Earth is expected to experience close brushes with two massive asteroids—99942 Apophis and 2024 YR4. Scientists are closely monitoring these space rocks, both of which initially sparked fears of potential impacts with Earth.
Apophis, a 370-meter-wide asteroid, is set to pass by our planet in 2029 at a distance so close that it will be visible to the naked eye. Meanwhile, asteroid YR4 2024 is projected to skim past in 2032, with its trajectory now expected to strike the Moon rather than Earth.
Debris Fallout Could Hit Earth
Although Earth might dodge direct collisions, the aftermath could still pose threats. If YR4 2024 hits the Moon—currently estimated to have a 4.3% probability—it could generate 100 million kilograms of debris. Scientists warn this could send meteorites hurtling toward Earth, potentially damaging satellites, the International Space Station (ISS), and endangering astronauts in orbit.
A History of Near Misses and Impact Events
When first discovered, both Apophis and YR4 2024 were calculated to have trajectories that intersected Earth’s orbit, raising serious alarms. Revised projections now indicate they will likely miss—but not without consequences.
According to astrophysicist Chris Lintott of the University of Oxford, asteroid impacts are rare but inevitable over time. “There’s one of these every 10 million to 100 million years,” Lintott told The Guardian, adding, “Most asteroids in the solar system exist in the asteroid belt, which is between Mars and Jupiter, but they become disrupted… and they can move into orbits that cross the Earth.”
Dino-Killer-Class Asteroids: A Low-Frequency But High-Impact Threat
Planetary astronomy professor Colin Snodgrass from the University of Edinburgh noted that while “not very often,” impacts similar to the one that wiped out the dinosaurs 65 million years ago still occur. He confirmed that four such “dino-killer” asteroids are known to scientists but are not currently near Earth.
Smaller Rocks, Big Danger
Smaller asteroids can still cause significant damage. In 2013, a 20-meter-wide asteroid exploded over Chelyabinsk, Russia, releasing energy equal to nearly 30 Hiroshima bombs. The blast shattered windows, damaged buildings, and injured over 1,000 people. In the last two decades, at least 556 meteors or asteroids have entered Earth’s atmosphere—one even crashing through a house in the southeastern United States.
Global Surveillance and Defensive Missions
Space agencies worldwide are preparing for potential threats. NASA and the European Space Agency have ramped up missions to identify hazardous asteroids and comets. The newly operational Vera C. Rubin Observatory in Chile recently discovered seven previously unseen near-Earth asteroids.
Venus, too, may be sheltering “invisible” asteroids, which could become dangerous with only a minor orbital shift, according to a recent study.
Human Capability to Deflect Asteroids: The DART Success
In 2022, NASA’s DART mission demonstrated that humanity can intervene. A small spacecraft deliberately crashed into the asteroid Dimorphos, successfully altering its trajectory. The impact shattered the rock and released so much debris that Earth may witness a new meteor shower from Didymos, Dimorphos’s larger companion.
