Scientists in France have figured out the birth date of the moon, as well as how the planet was formed.

Scientists have determined that the moon's creation was within 100 million years to the birth of the solar system, according to Fox News.

The new discovery about the origin of the moon may also help solve a mystery about why the moon and Earth appear identical in makeup.

Scientists suggest that the moon was formed 4.5 billion years ago by a collision between a Mars-sized object named Theia and Earth. This suggests that more than 40 percent of the moon was made up of debris from the impacting body.

While Theia was chemically different from Earth, recent studies reveal that the moon and Earth are very similar in terms of isotopes.

"This means that at the atomic level, the Earth and the moon are identical," study lead author Seth Jacobson, a planetary scientist at the Côte d'Azur Observatory in Nice, France, told Space.com. "This new information challenged the giant impact theory for lunar formation."

Jacobson and his colleagues solved the mystery of how the moon was formed by simulating the growth of the solar system's rocky planets--Venus, Earth, Mars and Mercury--from a protoplanetary disk of thousands of planetary building blocks orbiting the sun.

The scientists analyzed how the planets formed and grew from more than 250 computer simulations.

They found that after the last giant impact formed the moon, the mantle would have been stripped of iridium, platinum and their cousins. The elements are still present in the mantle, but only in small amounts, which suggests that only a small portion of material accreted onto Earth after the moon was formed.

Hence, analyses show that the moon required a faster, more energetic collision than was previously believed, which means the impact took place relatively late with an older protoplanetary disk.

"A late moon-forming event, as suggested by our work, is very consistent with an identical Earth and moon," Jacobson said.

"Older disks tend to be dynamically more active, since there are fewer bodies left in the disk to distribute energy amongst," he added.

The new findings suggest that the moon and Earth formed together, and evidence from meteorites from Mars suggest that the Red Planet formed as little as a few million years after the solar system developed.

"This means that Earth and Mars formed over dramatically different timescales, with Mars forming much faster than the Earth," Jacobson said. "How can this be? Is it just a matter of size? Location? What about Mercury and Venus? (...) "I think these are some of the really important questions that we, as a community of planetary scientists, will be addressing in the future."