The effectiveness of NASA’s planetary defense capabilities was highlighted when the Scout system forecasted the impact of asteroid 2024 BX1 over Germany. The asteroid disintegrated harmlessly 95 minutes after it was detected, showcasing the precision of near-Earth object (NEO) tracking systems. (Artist’s concept.) Credit: SciTechDaily.comNASA’s Scout system accurately anticipated the impact of asteroid 2024 BX1 over Germany, indicating progress in planetary defense by detecting and monitoring small, harmless asteroids before they enter Earth’s atmosphere.This demonstration of planetary defense capability was made possible by the Scout impact assessment system, which calculated the impact location and time of the asteroid 2024 BX1 as it entered Earth’s atmosphere.A small 3-feet (1 meter) asteroid disintegrated harmlessly over Germany on Sunday, January 21, at 1:32 a.m. local time (CET). The NASA’s Scout impact hazard assessment system, which monitors potential asteroid discoveries, provided advance notice about the impact location and time, 95 minutes before it occurred. This marks the eighth time in history that a small Earth-bound asteroid has been detected while still in space, before entering and disintegrating in our atmosphere.The asteroid’s impact generated a bright fireball (see video below), or bolide, visible from as far away as the Czech Republic, possibly scattering small meteorites on the ground around the impact site about 37 miles (60 kilometers) west of Berlin. Later, the asteroid was named 2024 BX1.
This map displays the location where the small asteroid 2024 BX1 safely entered Earth’s atmosphere over Germany, around 37 miles (60 kilometers) west of Berlin, on Jan. 21. The impact time and site were predicted by NASA’s Scout system within 1 second and about 330 feet (100 meters). Credit: NASA/JPL-CaltechAlthough NASA tracks near-Earth objects (NEOs) of all sizes, it is specifically responsible for detecting and monitoring NEOs that are 140 meters in size and larger, as mandated by Congress. These objects can be observed much earlier than smaller ones like 2024 BX1. While these tiny asteroids do not pose a threat to life on Earth, they serve as a useful demonstration of NASA’s planetary defense capabilities, such as Scout’s rapid-response trajectory computation and impact alerts.How They KnewThe asteroid 2024 BX1 was initially sighted by astronomer Krisztián Sárneczky at the Piszkéstető Mountain Station of the Konkoly Observatory near Budapest, Hungary, less than three hours before its impact. These early observations were reported to the Minor Planet Center, an internationally recognized repository for the position measurements of small solar system bodies, and automatically posted on the center’s Near-Earth Object Confirmation Page for other astronomers to make additional observations.Scout, developed and operated by the Center for Near Earth Object Studies (CNEOS) at NASA’s Jet Propulsion Laboratory in Southern California, automatically retrieved the new data from the page, deducing the possible trajectory and chances of the object impacting Earth. CNEOS calculates the orbit of every known NEO to provide assessments of potential impact hazards for the Planetary Defense Coordination Office (PDCO) at NASA Headquarters in Washington.
In the late evening of January 20, 2024, astronomer Krisztián Sárneczky detected an asteroid on an imminent collision course with Earth. Just hours later, it struck our planet’s atmosphere 50 km west of Berlin, producing this stunning fireball at 01:32 CET, Sunday, January 21. Later named 2024 BX1, this is just the eighth asteroid that humankind has spotted before impact. Thanks to the rapid response and information sharing from Earth’s asteroid and fireball communities, including ESA’s Near-Earth Object Coordination Centre, many people were able to see and record this spectacular sight, despite it taking place with just hours’ notice and in the middle of the night. This video was captured by the AllSky7 network. Credit: ALLSKY7 / Sirko Molau – AMS16 KetzuerWith three observations posted to the confirmation page over 27 minutes, Scout initially identified that an impact was possible and that additional observations were urgently needed. As astronomers across Europe reported new data to the Minor Planet Center, the asteroid’s trajectory became better known and the probability of its impacting Earth significantly increased.Seventy minutes after 2024 BX1 was first seen, Scout reported a 100% probability of Earth impact and started to narrow down the location and time. As tracking continued and more data became available over the next hour, Scout improved estimates of the time and location. Since the asteroid disintegrated over a relatively populated part of the world, many photos and videos of the fireball were posted online shortly after the event.
Visualization of the trajectory and impact of asteroid 2024 BX1 on January 21, 2024, created using the Flyby Visualization Tool of ESA’s Near Earth Object Coordination Centre. Credit: ESA, CC BY-SA 3.0 IGOTracking NEOsThe first asteroid to be discovered and tracked well before impacting our planet was 2008 TC3, which entered our atmosphere and broke up over Sudan in October 2008. That 13-foot-wide (4-meter-wide) asteroid scattered hundreds of small meteorites over the Nubian Desert.In early 2023, another tiny asteroid, designated 2023 CX1, was detected seven hours before it entered Earth’s atmosphere over northwestern France. As with 2024 BX1, Scout accurately predicted the location and time of impact.With NEO surveys becoming more sophisticated and sensitive, more of these harmless objects are being detected before entering our atmosphere, providing real exercises for NASA’s planetary defense program. The details gathered from such events are helping to inform the agency’s mitigation strategies should a large and hazardous object on a collision course with our planet be detected in the future.
