The moon has been a focal point for space research and exploration for years, yet we’re still far from fully understanding its origins. Take its age, for example – researchers have just discovered that the moon is about 40 million years older than previously thought.

In a study published by the European Association of Geochemistry, scientists looked at the age of crystal formations found in rock samples from the moon’s surface to determine its age. The prevalence of crystals called zircon in the samples, collected years ago from NASA’s Apollo program, suggests that the surface of the moon was created around 110 million years after the formation of the solar system. The scientists used analytical techniques including mass spectrometry to measure the presence of particular molecules in the rock. Another method of analysis, atom-probe tomography, was used to detect the amount of radioactive decay in the samples — which in turn was used to determine the age of the crystals in the rock.

NASA holds a theory that a Mars-sized object collided with Earth several billion years ago to form the moon. This new understanding of the age of the moon actually gives scientists a rough idea of when that collision might have occurred. This finding highlights the importance of exploratory missions like the Apollo 17 mission at the heart of this discovery. The 1972 manned mission to geologically survey the surface of the moon resulted in 243 pounds of lunar material being brought back to Earth — only for it to be examined by researchers 51 years later.

To date, NASA says that more than 105 robotic spacecraft have been launched to explore the moon, so the opportunities for more findings are boundless. Although the next NASA-led manned mission to the moon won't happen until 2025 at the earliest, we can expect more rover programs to shed more light on the makings of the surface of the moon.