The discovery of an incoming asteroid by experienced asteroid hunter Sárneczky led to a coordinated global response, culminating in the successful observation of the impact of asteroid 2024 BX1 near Berlin. This event highlights advances in space surveillance technology and the value of international cooperation. Photo credit: Issues.fr.com
- On January 20, 2024, astronomer Krisztián Sárneczky discovered an asteroid on an imminent collision course with Earth.
- A few hours later, it hit our planet's atmosphere 50 km west of Berlin and created a breathtaking fireball.
- Named “2024 BX1,” it is the eighth asteroid discovered by humanity before the impact – and the third discovered by Sárneczky.
Discovery of asteroid 2024 BX1
It was on Saturday, January 20, at 10:48 p.m. CET when experienced asteroid hunter Sárneczky discovered a new asteroid using the 60 cm Schmidt Telescope at the Piszkéstető mountain station, part of the Konkoly Observatory in Hungary.
He immediately sent his data on the asteroid's trajectory to the Minor Planet Center, but with only three initial observations it was impossible to say for sure whether it was on a collision course with Earth.
However, Sárneczky continued to track the asteroid and a few minutes later shared four more observations that clearly indicated a 100 percent probability of an imminent impact.
The final discovery of asteroid 2024 BX1 (originally known as Sar2736 before impact) by Luca Buzzi of the Schiaparelli Observatory in Italy. Recording began on January 20, 2024 at 00:24:55 UTC. The asteroid moves upward from the center of the image and begins to disappear as it enters Earth's shadow. Photo credit: L. Buzzi, GV Schiaparelli Observatory
Global response and impact
Automated impact monitoring systems around the world, including ESA's Meerkat, responded to this new data, springing into action and alerting astronomers and asteroid experts.
Sárneczky continued to make and report his observations, and he was soon joined by others in Europe. More than a dozen observatories focused on the incoming object. With their help, it soon became clear that the small, one-meter-wide asteroid would impact Earth in less than two hours, about 50 km west of Berlin, Germany.
Predicted impact location and time calculated by ESA's upcoming Meerkat impact warning system from the first 14 observations of the object Sar2736 (later named asteroid 2024 BX1). Meerkats update their ratings as they receive new sightings. Image credit: ESA, CC BY-SA 3.0 IGO
Asteroids of this size hit Earth on average every two weeks. They don't pose much of a threat and most are never discovered. But they can help us understand how many small asteroids exist, and we can study the fireballs they produce to determine what they're made of – if we catch them on camera.
Fortunately, large asteroids several kilometers in diameter are much easier to detect and are relatively rare. The vast majority of near-Earth asteroids that would cause devastating damage if they hit our planet have already been spotted, and we don't know that any of them will collide with our planet for at least the next hundred years.
ESA's Gaia spacecraft maps more than 150,000 asteroid orbits. Image credit: ESA/Gaia/DPAC, CC BY-SA 3.0 IGO, Thanks: Stefan Jordan, Toni Sagristà, Paolo Tanga; Gaia Sky (developed by Toni Sagristà); Gaia DR3 data (https://www.archives.esac.esa.int/gaia)
The event and its meaning
As Saturday evening turned into Sunday morning, astronomers continued to track asteroid 2024 BX1 until it entered Earth's shadow and disappeared from view at 1:25 a.m. ET.
The observers held their breath, but they didn't have to wait long. Minutes later, at 01:32 CET, 2024 BX1 hit Earth's atmosphere, leaving an explosive trail in the night sky. Many people in the Berlin area and throughout Central Europe were able to witness the fireball and a handful of people and automated camera systems even managed to record it.
Late in the evening of January 20, 2024, astronomer Krisztián Sárneczky discovered an asteroid on an imminent collision course with Earth. A few hours later, it hit our planet's atmosphere 50 km west of Berlin and created this amazing fireball at 01:32 a.m. CET on Sunday, January 21st. It was later named 2024 BX1 and is only the eighth asteroid discovered by humanity before the impact. Thanks to the rapid response and information sharing from the asteroid and terrestrial fireball communities, including ESA's Near Earth Object Coordination Center, many people were able to see and record this spectacular spectacle, even though it took place just hours in advance in the middle of the night. This video was captured by the AllSky7 network. Photo credit: ALLSKY7 / Sirko Molau – AMS16 Ketzuer
Only eight asteroids were discovered before they hit Earth's atmosphere. The first of these discoveries took place in 2008, four have been discovered in the last two years alone. As humanity's ability to detect smaller space objects improves, this number is likely to increase exponentially in the coming years.
In the three hours between discovery and impact, around 180 observations were transmitted to the Minor Planet Center, including those from ESA's Near-Earth Object Coordination Center in Tenerife, Spain.
Visualization of the trajectory and impact of asteroid 2024 BX1 on January 21, 2024, created using the Flyby visualization tool from ESA's Near-Earth Object Coordination Center. Image credit: ESA, CC BY-SA 3.0 IGO
Thanks to the rapid response and information sharing of the asteroid and fireball communities on Earth, many people were able to see and record this spectacular spectacle, even though it occurred only a few hours in advance and in the middle of the night.
The hunt is now on for potential meteorites that survived the fiery journey through the atmosphere and reached the ground.
For more on this story, see Small Asteroid Discovered on Imminent Collision Course with Earth.