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NASA’s Efforts to Identify and Mitigate Asteroid Threats

In February, the asteroid designated 2024 YR4 gained significant attention when analysis from NASA’s Center for Near Earth Object Studies (CNEOS) indicated a potential impact with Earth on December 22, 2032. The calculated likelihood of a collision peaked at over 3%, marking a historic high for an object of its size, which raised alarms about the possible consequences of such an event.

Subsequent observations, however, reduced this probability to below 1%, and 2024 YR4 has since been removed from the list of potential impactors. This incident highlights the critical need for comprehensive monitoring of asteroid populations to assess potential threats to Earth. By distributing scientific data broadly, researchers are better equipped to evaluate risks posed by near-Earth objects and enhance the chances of identifying future threats.

James “Gerbs” Bauer, principal investigator for NASA’s Planetary Data System Small Bodies Node at the University of Maryland, stated, “The planetary defense community realizes the value of making data products available to everyone.”

Tracking Potentially Hazardous Asteroids

Both professional and citizen scientists contribute to the tracking of asteroids on a global scale. The Minor Planet Center, based at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, consolidates and validates numerous observations of asteroids and comets that are reported worldwide. NASA’s Small Bodies Node disseminates this data to anyone interested in utilizing it.

A near-Earth object (NEO) is defined as an asteroid or comet with an orbit that brings it within 120 million miles of the sun, allowing it to traverse Earth’s orbital path. If a newly identified object fits this definition, information about it is listed on the Minor Planet Center’s NEO Confirmation Page. The planetary science community, regardless of professional status, is encouraged to monitor these objects to determine their trajectories.

When an asteroid’s path appears to pose a risk, CNEOS notifies NASA’s Planetary Defense Coordination Office, which oversees the agency’s ongoing efforts to safeguard Earth from hazardous asteroids. This office also coordinates the International Asteroid Warning Network (IAWN), fostering global collaboration among asteroid observers and modelers.

Centers like CNEOS conduct detailed analyses to assess the likelihood of an asteroid colliding with Earth. The open data philosophy allows for extended collaboration and cross-validation, thereby improving the precision of impact data assessments.

Understanding the Risks of Asteroid 2024 YR4

The NASA-funded ATLAS (Asteroid Terrestrial-impact Last Alert System) survey initially discovered the asteroid 2024 YR4, which is tasked with identifying potentially dangerous asteroids. Further analysis incorporated data from various observatories supported by NASA and other telescopes affiliated with the IAWN.

Initially, 2024 YR4’s trajectory was widely uncertain. As more observations were gathered, projections indicated an increased likelihood of impacting Earth on December 22, 2032. However, continued data collection eventually indicated that the asteroid would pass safely without risk of collision.

The availability of diverse data for analysis empowers scientists to rapidly gain insights into NEOs. Often, this includes leveraging observations from observatories primarily dedicated to astrophysics or heliophysics rather than exclusively tracking asteroids.

Bauer noted, “The planetary defense community both benefits from and is beneficial to the larger planetary and astronomy-related ecosystem.” The data from NEO surveys can assist in identifying astrophysical events like supernovae, while astronomical surveys produce information valuable for planetary defense.

Navigating Asteroid Threats with Proactive Measures

In a landmark achievement in 2022, NASA’s DART (Double Asteroid Redirection Test) mission successfully altered the orbit of the asteroid Dimorphos by impacting it, reducing its orbit period around its companion asteroid, Didymos, by 33 minutes. Although Didymos poses no threat to Earth, the mission established a viable strategy for averting future asteroid collision threats.

To enhance early detection of potential asteroid threats, NASA is developing the NEO Surveyor, a pioneering space-based observatory specifically designed to identify asteroids and comets that could endanger Earth. Slated to launch in the fall of 2027, the data acquired by this mission will be made publicly accessible through NASA archives.

Bauer emphasized, “Many of the NEOs that pose a risk to Earth remain to be found. An asteroid impact has a very low likelihood at any given moment, but the implications could be severe, making open science a crucial element of vigilance.”

Source
phys.org