TEMPO.CO, Jakarta - Recent observation using the James Webb Space Telescope confirms that the "city-killer" asteroid or 2024 YR4 will not collide with Earth or the Moon as it passes by in 2032.
Based on data collected on February 18 and 26 using the infrared instrument of the telescope, astronomers from the United States' National Aeronautics and Space Administration (NASA) updated their calculations for the near-Earth asteroid's trajectory. As a result, the likelihood of the asteroid colliding with the Moon, previously estimated at 4.3 percent, has now decreased to zero.
Although it will not collide, the asteroid is expected to pass relatively close to the Moon, at a distance of about 13,200 miles or 21,200 kilometers from the lunar surface. This distance is even closer than some artificial satellites orbiting the Earth. Meanwhile, Asteroid 2024 YR4 is also confirmed to pass far from Earth when it re-enters the inner solar system at its closest approach in about six years.
NASA stated that this observation was made possible thanks to the high sensitivity of the James Webb telescope, although it also pushed the telescope's capabilities to their limits.
"Since spring of 2025, the asteroid has been unobservable from both Earth and space-based observatories except for this use of Webb," a NASA official said in a written statement quoted from a report by Live Science, March 5, 2026. They added that this recent observation is among "the faintest ever observations of an asteroid" in history.
Asteroid 2024 YR4 was first discovered in late 2024 by the Asteroid Terrestrial-impact Last Alert System (ATLAS) network. Subsequent observations indicated that the asteroid has a diameter of about 53 to 67 meters, roughly equivalent to the height of the Leaning Tower of Pisa in Italy.
With this size, the asteroid has been dubbed a "city killer" because if it were to collide with Earth, it could produce an energy equivalent to hundreds of atomic bombs dropped on Hiroshima and potentially destroy a city.
At the beginning of the observations, astronomers initially estimated a small chance of the asteroid colliding with Earth. The collision probability even reached 3.1 percent, which was noted as one of the highest probabilities for asteroid collision ever calculated. However, after additional data from JWST and other telescopes was analyzed, the probability was eventually confirmed to be zero.
Although the threat of a collision has been ruled out, Asteroid 2024 YR4 remains an important object for astronomers to study planetary defense models. NASA also plans to observe the asteroid again using JWST in 2028 when it approaches Earth once more.
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