Fragments of an asteroid of mysterious origin have been found outside Berlin

Scientists have found pieces of a meteorite that fell near Berlin just after midnight on January 21. It is a rare discovery, from an asteroid that was identified before it entered the Earth's atmosphere. Only a few such events in the recent past have allowed astronomers to trace the origin of rocks coming into the solar system.

Early analysis of the parts revealed something equally rare. The meteorite is an operetta, a category with unknown origins that some scientists believe may be pieces of the planet Mercury. They are so rare that they make up only 80 of the 70,000 or so meteorites collected on Earth before last month's event.

“It's really exciting,” said Sarah Russell, a meteorite expert at the Natural History Museum in London. “There are very few operettas.”

The asteroid that became the meteorite (or rather the meteorite fragments) was initially spotted by Hungarian astronomer Christian Szarnieczky, three hours before it collided with Earth's atmosphere. A network of cameras tracked the incoming rock, 2024 BX1It fell near Reebeck, a village outside Berlin. It is estimated that the rock was small, measuring less than three feet in size. It still emits a brilliant flash that was captured by cameras in many parts of Europe.

Immediately upon hearing the news of the meteorite's fall, Peter Jeniskins, an astronomer At the SETI Institute In California, I bought a plane ticket.

“Saturday afternoon I found out about it,” he said. “Late Saturday evening I was on a plane to Berlin.”

During a nine-hour stop in Newark, Dr. Jeniskens calculated where pieces of the meteorite could be found, so that he and nearly two dozen students and volunteers could begin searching for fragments immediately when it landed early Monday morning.

For several days they hunted across the fields around Rebek. “We couldn't find anything,” he said.

But on Thursday, January 25, a Polish team of meteorite hunters announced that they had found the first piece of the meteorite. “They can show us what to look for,” Dr. Jeniskens said. The meteorites were not black as expected from their passage through the atmosphere, but rather were light, like terrestrial rocks.

With this information, within just two hours, one of Dr. Jeniskens' team, a student at the Free University of Berlin named Dominik Dieter, found a meteorite sitting above the Earth's surface. More were quickly spotted.

“It was unbelievable,” Dr. Jeniskens said. “We found more than 20 fragments.”

Researchers at the Natural History Museum in Berlin analyzed the minerals in the fragments using a microelectronic probe. This revealed that the rocks looked like aubrites. This was the first time such meteorites had been collected in a tracked fall path.

The source of the meteorite, named after the French town of Aubris near where it was first found, remains a mystery, because its composition does not match other known sources of meteorites in the solar system. Some research has suggested that they are parts of the planet Mercury, but not all scientists support this origin story.

If the operetta came directly from Mercury, then 2024 BX1 should have originated in the inner solar system. However, by tracing its path, it appears that the asteroid's initial orbit was just that Much wider and beyond Earth's orbit.

“So this object cannot come to us directly from Mercury,” said Mark Fries, a planetary scientist at NASA's Johnson Space Center.

However, it is possible that operettas were ejected from Mercury long ago into the asteroid belt between Mars and Jupiter, forming a group called E-type asteroids. The orbit of 2024 BX1 does not completely rule out this idea, although Dr. Fries remains skeptical.

Whatever their origin, the fragments of 2024 BX1 will be scientifically fascinating. “I'm sure it will be a priority to find out its composition and how it compares to other meteorites,” Dr. Russell said.

Tracking small asteroids like these before they collide with Earth's atmosphere is also crucial to defending the planet from asteroids. Small objects from space don't get discovered all the time but can pose problems for people on Earth, like the 65-foot-wide Chelyabinsk meteorite that exploded over Russia in 2013, said Davide Varnocchia, of NASA's Center for Near-Earth Object Studies. Injuring hundreds of people. Knowing the routes in advance can give people time to get to safety.

“If you can send a warning, no one will get hurt,” he added.