First-Known Boomerang Meteorite? This Space Rock Might Have Come From… Earth
A group of scientists have recently discovered a meteorite that offered a surprise to everybody. While it may resemble a typical meteorite, this one has a peculiar chemical composition that’s strikingly similar to that of rocks found deep within the Earth’s oceans. Considering this find, scientists think the meteorite may have originated on Earth.
A Meteorite from Earth
The meteorite may have been ejected into space from Earth in some cosmic event, and in time, it found its way back home. It was discovered in the Maghreb region in 2018 and called Northwest Africa 13188. It weighs nearly 23 ounces, and its chemical makeup mainly consists of the minerals plagioclase and pyroxene, making up one-third of the rock. To gain more knowledge about the meteorite, scientists have studied the isotopic composition of the rock, particularly focusing on oxygen.
By analyzing the ratios of oxygen isotopes, researchers can discern the origin of a celestial body. In the case of the meteorite, the oxygen isotope ratios and the rock’s mineral components suggest that Earth was its place of origin. Upon closer examination of the rock’s well-developed fusion crust, it was revealed that the concentrations of isotopes of beryllium, helium, and neon are consistent with those that would result from exposure to cosmic rays over about 10,000 years. This evidence allowed scientists to assert that Northwest Africa 13188 was a meteorite that was initially launched from Earth and later re-accreted to its surface.
The Meteorite Is 10,000 Years Old
According to the definition, an object is a meteorite if it originates from a celestial body and attains an independent orbit around another celestial body, including the sun, and eventually returns to its point of origin. While getting proof for such a complex series of events is a challenge, the presence of terrestrial rock that was exposed to cosmic rays makes this case plausible.
Eager to learn more about the full story of this peculiar meteorite, researchers are conducting further isotopic analyses in hopes to shed light on how it escaped Earth’s gravity confines.