Observations from amateur and professional astronomers made it possible for NASA  to predict the precise time and landing location of an asteroid discovered less than 3 hours in advance. Now hunters are turning up fragments from the fall!

Another fragment of 2024 BX1 found
David Göttlich of Passau, Germany points to a small fragment of the meteorite he found nearly hidden beneath plants on Friday, Jan. 26. It had recently rained in the area but conditions are now improving as drier weather arrives.
David Göttlich

Like an unexpected guest crashing a party, a meter-size (3.3-foot) asteroid slammed into Earth’s atmosphere over Germany early on January 21st, producing a spectacular fireball. What made this event even more remarkable was that the asteroid, designated 2024 BX1, had been discovered less than 3 hours before impact.

Krisztián Sárneczky at Konkoly Observatory’s Piszkéstető Mountain Station in Hungary first recorded the asteroid when it was still just an 18th-magnitude blip in the constellation Lynx. Here’s the gif time-lapse of its movement:

2024 BX1 frame grab
This is a frame grab from X of the asteroid 2024 BX1 that Krisztián Sárneczky discovered just hours before it hit the Earth. Click image to animate.

Sárneczky reported his observations to the International Astronomical Union’s Minor Planet Center, and they were then automatically posted to the Near-Earth Object Confirmation Page (NEOCP). Other observations began to come in as word spread.

After three reports to the page over the next 27 minutes, NASA’s Scout hazard assessment impact system automatically flagged the new object as a potential impactor. Scout continually monitors NEOCP and calculates an object’s possible trajectory and chances of colliding with Earth. Similarly, the European Space Agency's Meerkat Asteroid Guard (Meerkat for short) scans NEOCP and computes preliminary orbits and impact potentials for newly discovered objects. Both programs were crucial in refining 2024 BX1's orbit.

NASA impact map for 2024 BX1
This map shows the location (yellow circle) where the small asteroid 2024 BX1 harmlessly broke up over Germany, about 60 kilometers west of Berlin, on January 21, 2024. A NASA system called Scout predicted the impact time and site within 1 second and about 330 feet (100 meters).
NASA / JPL-Caltech

With an impact now a real possibility, urgent calls went out for follow-up observations. European astronomers — primarily amateurs — dropped what they were doing to aim their telescopes at the asteroid and make additional position measurements. Just 70 minutes after Sárneczky’s discovery, Scout reported a 100% probability of impact and narrowed down the fall location to 60 kilometers (37 miles) west of Berlin, estimating an impact time of 0:33 UT (January 21).

NASA then turned to X (formerly Twitter) and at 7:08 p.m. EST (0:08 UT) — just 24 minutes before predicted impact — posted on its @AsteroidWatch account:

Heads Up: A tiny asteroid will disintegrate as a harmless fireball west of Berlin near Nennhausen shortly at 1:32am CET. Overseers will see it if it’s clear!

Three-foot-wide asteroid 2023 BX1 slams into the atmosphere near Berlin. Here are two additional videos: #1 and #2.
Michael Aye

Social media lit up with the news. Incredibly, those who got wind of the alert had only to walk outside at the appointed time to witness the asteroid’s crackling, tumultuous end, exactly when and where Scout had predicted. As it spalled to pieces in the atmosphere, the fireball was visible from as far away as Slovakia, according to reports in the American Meteor Society’s Fireball log.

Observers described the meteoroid’s fragmentation, but none reported any accompanying sounds. This might have indicated that it completely disintegrated with no fragments surviving the fiery plunge. Happily, that turned out to not be true.

2024 BX1 meteorite hunters
Friends and fellow meteorite hunters from Poland, Kryspin Kmieciak, Michał Nebelski, Filip Nikodem and Andrzej Owczarzak, happily show off freshly-found fragments from the formerly meter-wide asteroid 2024 BX1.
Filip Nikodem

On Thursday, January 25th, after three days of scouring the predicted fall site west of Berlin, four Polish meteorite hunters successfully recovered meteorite fragments. Some meteorite enthusiasts were a bit skeptical at first because the stones lacked the typical black, satiny fusion crust, which usually forms due to the brief but intense heating meteoroids undergo during atmospheric entry. But not all meteorites display such crust.

Berlin fall fragment
A fragment of the Berlin meteorite fall displays a light-gray fusion crust. White crystals that speckle the space rock could indicate a rare type.
Filip Nikodem

Achondrites known as aubrites are often light-toned and display a pale brown or light gray fusion crust. They’re also quite rare. While specimens found by the crew and others have yet to be classified, aubrites remain an intriguing possibility. Other clues seem to point in that direction, too, including a sulfurous odor, brecciated texture, and those large, white crystals, which might be enstatite, a mineral commonly found in aubrites.

Berlin fall interior
Impact with the ground fractured this Berlin meteorite fragment, exposing its paler gray interior.
Filip Nikodem

The four hunters have returned to the area to look for more and have been joined by many others, among them scientific researchers. We should be seeing and hearing more very soon, including a classification.

Krisztián Sárneczky
Krisztián Sárneczky, discoverer of pre-impact asteroids 2024 BX1 and 2023 CX1.
Szigeti Tamás / CC BY-SA 4.0

The asteroid, 2024 BX1, was Sárneczky’s third pre-impact asteroid discovery and only the eighth time an asteroid has been found and successfully predicted to collide with Earth. His previous discovery, the similar-sized 2023 CX1, slammed into the atmosphere on February 13, 2023, less than 7 hours after discovery. It dropped meteorites over Normandy, France. It was later classified as an L5-6 chondrite and christened Saint-Pierre-le-Viger after a nearby town. Scout was also instrumental in predicting the time and location of that fall.

Video by the AllSky7 Network

It’s heartening to see how a combination of alert observers, reporting sites, and sophisticated tools like Scout worked in tandem to alert the world to potential impactors. While this impactor was small, coordinated efforts in spotting and tracking objects could in turn lead to improved mitigation strategies for going after the big ones that could cause real harm.

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2024 BX1

Comments


Image of Anthony Barreiro

Anthony Barreiro

January 26, 2024 at 5:23 pm

This is a great story. Congratulations to Mr. Sarneckzy and the asteroid hunters.

Some years ago Peter Jenneskins gave a talk to our astronomy club about meteors and meteorites. He said that using magnets to find meteorites scrambles their magnetic fields (I'm sure that's not the right term) erasing potentially valuable information, and that picking them up with your bare hands contaminates them with oil from your skin. He said that you should handle meteorites with aluminum foil.

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Anthony Barreiro

January 26, 2024 at 5:24 pm

I meant to congratulate the meteorite hunters.

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Bob King

January 26, 2024 at 8:56 pm

Hi Anthony,

I think we can accept asteroid in this case 😉 (And thank you!)

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mjmorri

January 26, 2024 at 8:09 pm

Cannot remember where, but I also heard they should be handled with aluminum foil and not exposed to magnetic fields. Interesting color and grain structure to these ones.

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Bob King

January 26, 2024 at 8:59 pm

Hi Mj,

That's correct. It's the proper and preferred procedure. However if an individual doesn't intend to submit their find for laboratory analysis I think the rule can be relaxed. Also, in many cases, these things bury themselves in soil or slam into mud.

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Andrew James

January 27, 2024 at 12:56 am

Q. If a meteor falls from the sky, and lands is a meteorite, who owns it?

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Bob King

January 27, 2024 at 11:16 am

Hi Andrew,
The laws vary according to country. In the U.S. if it falls on your property it's yours (same in Canada). You can also collect meteorites on public lands in the U.S. A quick check on German law appears to show that meteorites belong to the finder. In India they're considered owned by the Geological Survey of India. Here are a few other examples: https://www.lpi.usra.edu/meetings/metsoc2001/pdf/5150.pdf

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louis-robinson

January 29, 2024 at 11:47 pm

However, collectors should note that it's illegal to export a meteorite from Canada without a permit.

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Bob King

February 2, 2024 at 11:06 pm

Hi Louis,
Yes, that's correct — an export permit is required. Thank you for adding that.

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Anthony-Mallama

January 28, 2024 at 8:56 am

This is a very interesting article, Bob. I am always glad to see amateurs getting involved in research.

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Bob King

January 30, 2024 at 10:56 am

Thanks, Anthony. It was Bill Gray who pointed out to me just how many amateurs were involved and they indeed comprised the majority. It is wonderful to see good work getting credit whether professional or amateur.

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jrmorgan07

January 29, 2024 at 10:59 pm

Was the feature shown in the lower-right corner of the video another near-earth object?

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Bob King

January 30, 2024 at 10:57 am

Dear Jrmorgan,
Great question! No, it was an internal reflection (flare) within the camera's lens caused by the brilliance of the fireball.

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