Water found deep within both the moon and the Earth may have the same origins according to a new study.
US researchers found evidence that water may have existed on our planet before the impact that created the moon.
This means that the moon contained water from its creation about 4.5 billion years ago.
Our planet is believed to have acquired water from a comet or meteorite many many years before.
Scientists believed that the moon's interior was dry but recent findings say samples from the Apollo missions have contained hydrogen needed for water.
For the current research, an analysis was done of the crystal and glass from the moon rocks.
According to Space.com, the scientists looked at the make-up of hydrogen isotopes and found they were similar to those found on Earth.
The finding suggested that water from the Earth and moon may share the same origins: meteorites that drift between Mars and Jupiter.
Space.com said these meteorites are thought to be some of the oldest objects in our solar system.
"We concluded that basically, the Earth formed with water. By the time of the giant impact, we don't know what happened, but not all of that water was lost like we had thought before," said study author Alberto Saal, a geological scientist at Brown University.
"Some of that water went to the moon."
The findings were published in the journal Science.