Asteroid Impact: 7-Stage Descent Revealed

Scientists have identified the 7 stages of a meteorite's life, from entering Earth's atmosphere to impacting the surface, through a study of 75 meteorites. The research, led by Peter Jenniskens of the SETI Institute and NASA Ames Research Center, sheds light on the physical processes involved in their descent.

The 7 stages of a meteorite's life are determined by different physical processes. The first stage begins high in Earth's atmosphere, where the falling space rock creates a shock wave. This turns the falling space rock into a "shooting star" streaking across the sky.

As the meteorite descends, it goes through several stages, including phase 3, where the space rock becomes a fireball and loses the most mass via melting. By phase 4, the meteorite may have lost up to 40% of its original mass. Phase 4 begins at around 40 miles (60 kilometers) over the surface of Earth.

The research could help understand the potential impact of a large asteroid entering Earth's atmosphere. The team found that space rocks go through periods of melting and fragmentation that occur at different altitudes, in addition to mere evaporation.

## Why it matters The study's findings have significant implications for our understanding of the life cycles of meteorites and the potential risks associated with large asteroid impacts. By understanding the physical processes involved in a meteorite's descent, scientists can better predict the consequences of a large asteroid entering Earth's atmosphere.

The research highlights the complexity of the processes involved in a meteorite's journey to Earth's surface. Rather than simply evaporating due to heat and friction, space rocks undergo a series of transformations, including melting and fragmentation, as they pass through the atmosphere.

The study's results provide valuable insights into the behavior of meteorites and asteroids, and could inform strategies for mitigating the risks associated with large asteroid impacts.