Let’s start with a little history of the Apollo space program. The objective of the program was to facilitate human landings on the Moon as well as the astronaut’s safe return. The program consisted of six missions, namely Apollo 11, 12, 14, 15 16 and 17 (the ascending numbering is in the chronological order).
The Apollo 14 Mission went to the moon in 1971 and explored its Cone Crater. The astronauts on the excruciation also brought some rocks, which were arbitrarily picked from the crater. All the lunar specimens brought back to the Earth have been inspected and studied to not only understand planet Earth’s lone natural satellite but also the planet itself. Scientists have also been studying them in connection with the evolution of our own planet.
In one such study, astronauts have put forward some amazing inference regarding one of the lunar relics collected by the Apollo 14 team. According to the team of geologists and astronauts analyzing the specimens brought by the Apollo 14 mission, one of the rock specimens was actually a four-billion-year-old chunk from planet Earth!
If this deduction is further established in the future, then this specimen will easily become Earth’s oldest rock. You may be wondering how on earth (pun intentional) a rock from this planet ended up on the moon. Before your mind starts weaving conspiracy theories regarding extraterrestrial phenomena, we are going to burst the bubble of how this terrestrial rock ended up on the moon, leading us to an astonishing tale of this stone ’s journey from the Earth to the moon and back.
An Asteroid or Comet Impact: The Initial Point of This Journey
Billions of years ago, when life hadn’t materialized on Earth, the collision of large asteroids and comets with our planet was pretty common. Scientists believe that this terrestrial rock ended up on the moon, due to such impact.
According to their hypothesis, a large comet or asteroid collided with Earth that resulted in the splatter of rocks from the Earth’s crust into the outer space, similar to splashes from a water-filled glass when an ice cube hits its surface.
These rocky splashes scattered into outer space and some of them landed on the Moon. It is important to mention that the moon was three times closer to the Earth then it is now. On the moon, these Earth specimens eventually got mixed up and buried with other lunar substances.
Why Scientists Are So Sure About the Terrestrial Origin of the Stone?
This is the first time when scientists have made such an astounding claim regarding any lunar specimen. Moreover, they are quite confident of the veracity of their hypothesis. The main reason for this confidence is the presence of mineral traces in the rock.
Geological Makeup of the Moon is Free of Minerals
The geological studies about the lunar crust have shown that it’s underneath environment is not suitable for the formation of minerals like the inner layers of the Earth’s crust. Scientists believe that minerals might be part of the core of the moon and they are really sure that the sample in question is not from that innermost layer of the natural satellite.
Zircon, Feldspar, and Quartz Are Present in the Rock
Scientists have identified traces of zircon, feldspar, and quartz in the rock. This discovery is the foundation of an hypothesis that this rock has splashed on the moon from the Earth. These minerals are fairly common within the Earth’s crust. However, no other lunar specimen contains any minerals, let alone these three distinctive gem minerals. It will be fitting to have a brief discussion of these three minerals.
Zircon: As the name suggests, zircon is the silicate compound of the zirconium element. Some fine specimens of this stone are used as diamond simulants. From transparent options to purple and pink, zircon has an entire array of natural colors that depends on the type of impurity it contains. Some zircon specimens also contain radioactive traces. Such specimens undergo the process of metamictization before the gemological faceting and processing.
Feldspar: This tectosilicate mineral makes up more than 41% of the Earth’s crust in the form of many sub-minerals. From typical rock-like structures to gems such as olivine, a whole range of unique mineral specimens are part of feldspar family. Scientists are yet to disclose which type of feldspar traces have been detected on that terrestrial-lunar rock.
Quartz: Quartz is one of the most abundant minerals present in the Earth’s crust. It has many different uses. Some fine quartz crystals are used in the manufacturing of ornamental items. On the other hand, it is also used in many electronic and mechanical devices due to its piezoelectric properties. On Earth, it is found in nearly every mineral environment. But on the moon, there is no sign of this mineral at all.
The Possible Explanation
The Cone crater from where the Apollo 14 team picked that stone was created some 26 million years ago. Craters are formed when small celestial bodies collide with planetary bodies in high velocities. So, the impact that created the Cone crater actually resulted in the excavation of rocks buried under the lunar surface. The Apollo 14 team just picked one of those excavated rocks among which one had terrestrial mineral traces.
Pre-Lunar Journey of the Stone
Scientists believe that the rock with all its mineral traces was created approximately 20 kilometers beneath the Earth’s surface. According to their studies, the Earth’s crust was the budding ground of mineral formation four billion years ago.
This discovery has also given traction to another conjecture that the entire Earth’s crust had a similar composition with traces of different minerals before the manifestation of biological life on the planet. However, this theory doesn’t have much logical backing in its favor to be taken as a serious scientific assertion.