Scientists around the world are closely monitoring asteroid 2024 YR4, as NASA and European Space Agency (ESA) officials have suggested there is a small chance it could collide with Earth within the next decade. Discovered on December 27, 2024, using telescopes stationed at the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) facility located in Río Hurtado, Chile, this asteroid is estimated to be between 130 and 328 feet wide. The ESA reports such asteroids typically impact Earth every few thousand years, potentially causing severe damage to localized areas.
Recent assessments indicate asteroid 2024 YR4 has about a 1.2% probability of impacting Earth on December 22, 2032. "Currently, no other known large asteroids have an impact probability above 1%," NASA noted on its blog. Due to this evaluation, the asteroid is currently ranked level 3 out of 10 on the Torino Impact Hazard scale. Although there are concerns, NASA remains optimistic, stating, "There have been several objects through the years whose risk levels have changed and eventually dropped off as more data came to light." New observations could result in asteroid 2024 YR4 being reassigned to zero as fresh data becomes available.
This classification is particularly significant, as it meets the criteria necessary to activate the two United Nations-endorsed asteroid reaction groups: the International Asteroid Warning Network (IAWN) and the Space Mission Planning Advisory Group (SMPAG). These organizations are tasked with coordinating international responses and observations related to asteroid 2024 YR4 and will update their assessments as necessary.
Looking at the facts, the asteroid is moving away from Earth and is now on an elongated orbit around the Sun, complicate efforts to monitor its path effectively. The ESA has advised astronomers to keep studying 2024 YR4 using the European Southern Observatory’s Very Large Telescope, as it is expected to fade from view over the coming months. The asteroid may remain on the risk lists until it is visible again, which is projected to be around 2028.
Some experts are cautioning against panic, emphasizing the possibility of a miss. David Rankin, an engineer from the Catalina Sky Survey, described the situation, saying, "This is one of the highest probabilities of impact from a significantly sized asteroid ever." He noted, "Most likely outcome is still a near miss." Nonetheless, the size of the asteroid—potentially causing severe regional damage—has necessitated serious planning. The IAWN is coordinating efforts to continually monitor the asteroid's movement and develop strategies for world governments should the need arise to prepare for potential impacts.
Colin Snodgrass, from the University of Edinburgh, expanded on the monitoring efforts, stating the very first step is triggering extended observations. If these efforts do not rule out impact, the next steps would involve detailed measurements, reconnaissance, and discussing potential countermeasures. Surveys have highlighted regions such as the eastern Pacific, northern South America, Africa, and South Asia as potential impact sites should the asteroid strike the Earth.
Given the nature of asteroids, their impact risk often appears to heighten initially due to uncertainty about their trajectories. Early on, limited observational data results in wide risk corridors, which may include paths intersecting Earth. With additional observations over time, scientists gain more certainty about the asteroid's path, allowing for narrower risk assessments. Currently, the track of asteroid 2024 YR4 is challenging to determine due to its eccentric orbit and its current motion away from Earth.
The Space Mission Planning Advisory Group is planning discussions on asteroid 2024 YR4 during their regular meeting in Vienna, where decisions may be made about proactive measures if its risk rating continues to indicate more than 1%. The possibility of diverting or destroying the asteroid via spacecraft, similar to NASA's recent Dart mission, may be on the table. Snodgrass remarked, "This asteroid is of the scale where missions like Dart could effectively be carried out if required; the technology is available, and it has been tested."
Given the collaborative global focus on planetary defense strategies, the situation remains fluid and continues to evolve as more data becomes available. Scientists are urging continued vigilance and are committed to monitoring asteroid 2024 YR4, balancing precaution and preparation against potential impacts with scientific integrity.