A new tiny impactor observed until shadow entrance
Krisztián Sárneczky has repeated himself for the third time, finding another small imminent impactor just before its impact with Earth in Europe.
The story began on Saturday, 20 January, at 21:48 UTC, the time of the first discovery image obtained from the Piszkéstető Observatory. Less than 30 minutes later, collecting more images and detecting the asteroid, the first set of astrometric positions was received by the Minor Planet Center and posted on the NEO Confirmation Page with the temporary designation Sar2736.
With just 3 positions, it was nearly impossible to know that the object was on a collision course with our planet. However, just 20 minutes later, the discoverers reported 4 more positions, and that's when the impact monitoring systems, including our own Meerkat, produced its first impact alert. It already gave an impact probability of 100% for the object, with an impact location placed somewhere between Germany and Sweden.
The discoverers continued reporting astrometry, and was soon joined by other European observers. Within minutes, the impact event circumstances became clear: this small metre-sized asteroid was going to impact Earth less than two hours later, roughly 50 km west of Berlin, Germany.
Over the next couple of hours more than a dozen observatories in mainland Europe, and our team from Tenerife, were able to obtain follow-up observations, until the latest possible instant: at 00:25 UTC the asteroid entered the shadow of the Earth and disappeared from view, while still under the watch of the Schiaparelli Observatory in Italy (see image).
Less than 8 minutes later, it became visible again as a bright fireball, observed by dozens of people all across central Europe. Some of them had been alerted through social media posts triggered by our imminent impactor systems, closing the loop from NEO discovery to fireball event. And all over a period of less than two hours, from first alert to impact, a success story for both the NEO and the fireball communities.
The asteroid was designated as 2024 BX1 by the Minor Planet Center, just after its impact. Congratulations to Krisztián, the Piszkéstető Observatory and all involved for this impressive third success in less than 2 years, a truly remarkable achievement.
Caption: The last detection of 2024 BX1 (then known as Sar2736) obtained by Luca Buzzi from the Schiaparelli Observatory in Italy (MPC code 204). The exposure was started at 00:24:55 UTC. The asteroid is moving from the bottom to the top of the image (heading North), and it is visible as a fading trail, due to its entrance into Earth’s shadow over the following 10 seconds. Credits: L. Buzzi, G. V. Schiaparelli Observatory.