The analysis of samples collected during NASA’s Apollo missions has pushed the Moon’s age back by 100 million years.

On 21 July 1969, humankind took its first steps on another celestial body as we walked on the surface of the moon.

In their few hours on the lunar surface, the crew of Apollo 11 collected and brought back to Earth 21.55 kg of lunar rock samples.

Now, 50 years later, these samples are still teaching us about important events of the early solar system and the history of the Earth-Moon system. Discovering the age of the Moon is also important to understand how and at which time the Earth formed, and how it evolved at the very start of the solar system.

Now, a new study led by Earth scientists at the University of Cologne’s Institute of Geology and Mineralogy has discovered the age of the Moon to be approximately 50 million years after the formation of the solar system. In other words, after our solar system formed, around 4.56 billion years ago, Earth’s Moon formed approximately 4.51 billion years ago.

This means that the moon is way older than what we initially thought.

An earlier study estimated that the Moon formed approximately 150 million years after the formation of the solar system and not 50 million years later, as this investigation concludes.

To find out how old the moon really is scientists analyzed the chemical composition of a wide range of samples collected during NASA’s Apollo missions. This study focuses on the chemical signatures of different types of lunar samples collected by the different Apollo missions.

“By comparing the relative amounts of different elements in rocks that formed at different times, it is possible to learn how each sample is related to the lunar interior and the solidification of the magma ocean,” explained Dr. Raúl Fonseca from the University of Cologne.

Scientists argue that Earth’s Moon most likely formed after a giant collision between a planetary body the size of Mars and the primitive Earth.

Over time, the Moon grew from the cloud of material that accumulated in Earth’s orbit.

The newborn moon was covered by an ocean of magma, which formed different types of rocks when it cooled.

“These rocks recorded information about the formation of the Moon, and can still be found today on the lunar surface,” reveals Dr. Maxwell Thiemens, former University of Cologne researcher and lead author of the study.

“Such observations are not possible on Earth anymore, as our planet has been geologically active over time. The Moon thus provides a unique opportunity to study planetary evolution,” added Dr. Peter Sprung, co-author of the study.