Asteroid 2020 XR passed by Earth at just under six times the distance from Earth to the Moon (LD) at 05:26 UTC on December 4, 2024. Its estimated diameter is between 300 – 700 m (984 – 2 297 feet) across.
The object belongs to the Apollo group of asteroids and is classified as a Potentially Hazardous Asteroid (PHA) — a category of near-Earth objects (NEOs) identified based on their potential to approach Earth closely and cause significant damage in the event of an impact.
To qualify as a PHA, an asteroid must have an orbit that brings it within 0.05 astronomical units (AU) of Earth’s orbit—about 7.5 million km (4.65 million miles)—and a diameter of at least 140 m (459 feet), which is large enough to cause considerable regional destruction. Although the “potentially hazardous” label doesn’t mean an asteroid will collide with Earth, it shows the need for close monitoring to track possible changes in its trajectory.
Despite 2022 XR’s classification as a PHA, the asteroid’s path during this flyby posed no threat to Earth.
Interestingly, the asteroid was first detected on December 4, 2020, by the Pan-STARRS 2 telescope at Haleakala Observatory in Hawaii, and its close approach to Earth occurred precisely four years to the day after its discovery.
“When astronomers first discovered 2020 XR, they thought it had a small chance of impacting Earth in 2028. But by going back and finding the asteroid in older data, they were able to refine its trajectory and rule out any hazard,” said Juan Luis Cano of ESA’s Planetary Defence Office.
The next close approach of asteroid 2020 XR to Earth will take place on November 7, 2028, at a distance of 47.2 LD / 0.12 AU. The object is not expected to come within less than 27.2 LD / 0.07 AU of our planet at least until December 2157.
What would happen if an asteroid the size of 2020 XR impacted Earth?
If an asteroid the size of 2020 XR (300 – 700 m / 980 – 2 300 feet) were to collide with Earth, the consequences would be devastating locally and globally. The overall severity would depend on factors like its composition, speed, impact angle, and whether it struck land or ocean.
During impact, such an asteroid would release an energy equivalent to 50 000 to over 700 000 megatons of TNT, far exceeding the largest nuclear explosions ever recorded.
On land, it would create a massive crater, incinerate the surrounding area, and cause widespread destruction over hundreds of kilometers.
An oceanic impact would generate enormous tsunamis, with waves potentially hundreds of meters high, inundating coastal areas thousands of kilometers away and causing widespread flooding and loss of life.
Globally, the impact would eject vast amounts of dust into the atmosphere, potentially blocking sunlight and triggering a “nuclear winter”-like effect.
This could disrupt agriculture and ecosystems for years, with severe consequences for biodiversity and human civilization, though it would not likely cause a mass extinction event.
References:
1 Close approach of asteroid 2020 XR – ESA – December 3, 20204
2 2020 XR – NEOCC/ESA – Accessed on December 4, 2024
3 2020 XR – MPC – Accessed on December 4, 2024
4 2020 XR – CNEOS – Accessed on December 4, 2024