The moon is older than we thought

UP UNTIL recently, the moon was thought to be 4,42 billion years old, but new research suggests it’s 40 million years older – making it 4,46 billion years old. Scientists came to this conclusion after studying pieces of moon rock taken during the last lunar landing.

Although the first study on the moon’s age was done 51 years ago when Apollo 17 returned to Earth, scientific techniques that now exist were not available then.

HOW WAS THE MOON FORMED?

During the earliest days of our solar system, when Earth was still forming, it is thought an object the size of Mars collided with our planet, blasting molten rock into space. The magma (molten rock) later hardened to become the moon.

Scientists believe zircon crystals are the first solids to have crystallised after the moon’s formation. Zircon is a very tough stone and lasts longer than diamonds.

HOW IS THE AGE DETERMINED?

During the Apollo 17 mission in 1972, American astronauts collected soil and rock samples for scientists to study. They recently analysed the zircon crystals found inside these rock fragments using a technique called atomic test tomography.

In the process, special microscopes are used to sharpen the lunar rock to a point (almost like a pencil sharpener) before lasers are used to study its chemical composition.

WHY IS THIS IMPORTANT?

The fresh analysis helps scientists better understand the history and evolution of the moon, as well as Earth.

“It’s amazing to be able to say that the rock you’re holding is the oldest part of the Moon we’ve found so far,” says Jennika Greer, who led the study.

“This is the starting point for so many questions about the Earth. If you know how old something is, you can better understand what happened in its history.”