Crystals help determine the time of a meteorite strike.

Crystals help determine the time of a meteorite strike.

2 billion years ago, a huge space stone (10 km) crashed into a rock near a place called Sudbury. Now researchers from Western and Portsmouth universities are examining the details of the impact using the technology of measuring surrounding crystals.

This is a new technique that can determine the date of impact. But these are only the first steps, as in a more detailed understanding it is possible to reveal the exact time of the appearance of life, both on our planet, and, possibly, on others.

We realize that this could not happen while the surface periodically succumbed to the attack of meteorites in the early years of our system. Therefore, it is important to understand when they stopped, which will help to understand how we got here and where we came from.

Scientists have applied new visualization methods to calculate the atomic nanostructure of ancient crystals in the field of impact. The analysis began to be carried out on the Sudbury crater (width - 150 km). Shock waves deformed minerals, including small crystals enclosing traces of radioactive uranium and lead. They can be used as miniature clocks to measure a geologic time scale.

For this purpose, specialized tools of the Western laboratory Zircon, ZAPLab and an atomic probe from CAMECA were used. The latter is able to cut and lift the tiny layers of crystal baddeleyite, common in terrestrial, lunar and Martian rocks and meteorites.

After that, the researchers measured the strain in the crystals and removed the layers, until atoms and isotopes were identified. As a result, we obtain a three-dimensional model of atoms and a map of their location. This method has great potential because it is the exact chronology of the formation and evolution of planetary crusts.

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