Over the Past 2.5 Billion Years, Our Moon Has Been Gradually Moving Away From Earth

By Aazam

October 20, 2022

Looking at the moon in the night sky, you will never be able to guess that it is slowly moving away from the earth

In 1969, NASA's Apollo mission installed reflective panels on the Moon. These have shown that the Moon is moving 3.8 cm away from the Earth every year

We recently discovered the perfect place to uncover the long-term history of our waning Moon

In the beautiful Karijini National Park in Western Australia, some valleys cut through 2.5 billion years old, rhythmically layered sediments

These are sediment-bound iron formations, consisting of distinct layers of iron and silica-rich minerals

Once widely deposited on the ocean floor and now found in the oldest parts of the earth's crust

Deeper gaps are composed of a softer type of rock that is more susceptible to erosion

A closer look at the outcrops reveals the presence of additional regular, small-scale variation

Right now, the major Milankovitch cycles change every 400,000 years, 100,000 years, 41,000 years, and 21,000 years

We now need other reliable data and new modeling approaches to trace the Moon's evolution over time