For a long time, scientists believed that Earth’s shape was influenced by volcanoes, earthquakes, and continents moving apart. They also knew that meteorite impacts had an impact on our planet. However, recent research suggests that the Milky Way galaxy may have played a role in shaping our planet’s crust.
To understand this idea, astronomers compared maps of hydrogen gas in the Milky Way with chemical fingerprints found in ancient crystals on Earth. The study found that when the Solar System passed through spiral arms of the galaxy, it increased the number of comets and asteroids hitting Earth.
Zircon crystals, tiny time capsules formed over billions of years, hold clues about what our planet was like at the moment they grew. These crystals can be dated and show chemical variations, which could indicate whether the magma came from deep inside Earth or had contact with surface water.
The new study found correlations between periods when the Solar System passed through spiral arms and spikes in zircon oxygen variability. This suggests that Earth’s crust may have been influenced by the Milky Way’s galactic journey.
Source: https://www.sciencealert.com/signs-of-our-galaxys-arms-may-be-trapped-in-some-of-earths-crystals