The asteroid that lit up the sky above Berlin was the fastest spinning space rock

Asteroid 2024 BX1, which entered Earth’s atmosphere and disintegrated over Berlin, Germany on January 21, 2024, appears to be the fastest-spinning asteroid ever observed.

The asteroid, which was no more than 1 meter wide, rotated every 2.588 seconds, equivalent to about 30,000 rotations per day.

This discovery was made by Maxime Devogele of the European Space Agency’s Near-Earth Object Coordination Center in Italy and his colleagues, who captured images of the asteroid before the impact. Despite the asteroid’s high speed of about 50,000 kilometers per hour, its elongated shape made changes in brightness particularly prominent in these images.

Asteroids rotate for a number of reasons, such as collisions earlier in their lives.

In general, space rocks larger than a kilometer cannot rotate more than once every 2.2 hours because they would fall apart. However, smaller asteroids such as 2024 BX1 can withstand much faster spins because they are more compact and possess greater internal strength.

Measuring the spin of these types of objects could be useful for planetary defense, as it can let us know how strong a small asteroid is and how likely it is to survive its passage through Earth’s atmosphere. “If it’s hard, it’s going to react differently than if it’s a piece of snow that has no internal strength,” Devogele says.

The observation published on preprint server arXiv states that Near Earth objects (NEOs) on an impact course with Earth can move at high angular speed. Understanding their properties, including rotational state, is crucial for assessing impact risks and mitigation strategies.

This discovery is important because it challenges our understanding of asteroid spins and their potential impact on Earth.

As we continue to discover and track near-Earth objects, understanding their physical properties, including their spin rates, will be critical in minimizing the risks they pose to human life and infrastructure.