Space Rocks' Fiery Descent: 7 Stages Revealed

Scientists have identified seven distinct stages that describe the transformation of space rocks entering Earth's atmosphere and surviving to become meteorites. Contrary to previous beliefs that rocks primarily evaporated, this new analysis, based on 75 meteorite falls, highlights the significant roles of melting and fragmentation. These processes are now understood to be critical in determining mass loss, deceleration, and the final landing locations of fragments.

The journey begins with the formation of a meteor as the rock heats up from atmospheric friction. As it intensifies into a fireball, melting becomes the dominant factor, stripping molten material from the surface. This stage can account for up to 40 percent of the rock's original mass loss.

Fragmentation begins around 60 kilometers altitude as increasing air pressure causes the rock to fracture. This breakup accelerates deceleration, with more fragmentation leading to faster speed loss. The shape of the surviving rock can influence fragment dispersal, with intact rear sections creating a vacuum that draws smaller pieces along.

The final phase involves the breakup of the main rock, causing a bright flare and scattering fragments. These fragments then continue to melt and fragment, slowing down until they cease to glow, leaving behind a fusion crust. This research offers crucial insights into the behavior of potentially dangerous asteroids.