New Kind of Meteorite Believed From Earth That Went to Space Then Came Back Under Investigation

In an unexpected turn of events, scientists are investigating the possibility that a black rock found in Morocco in 2018 ventured into outer space and then returned to Earth. Dubbed 'Northwest Africa (NWA) 13188', this rock could potentially be the first known meteorite to have embarked on such a remarkable round trip.

Boomerang Space Rock

The peculiarities surrounding the 646-gram 'boomerang space rock' go beyond its potential celestial journey, as per Science Alert. NWA 13188's appearance, with its bubbly texture and crystal composition, closely resembles the rocks formed by molten minerals near subduction zones on Earth.

When examining its oxygen isotopes and trace elements, doubts arise regarding its meteoritic origin, at least in the conventional sense. Geophysicist Jérôme Gattacceca, who presented the findings at the Goldschmidt geochemistry conference in France, suggests that the rock has undergone a fascinating journey, spending a significant duration in orbit.

The concentrations of Helium-3, Beryllium-10, and Neon-21 found in NWA 13188 indicate exposure to cosmic rays, a form of radiation prevalent in space but mostly blocked by Earth's magnetic field. Although the isotopic levels were lower than those found in other meteorites, they were considerably higher than those typically seen in terrestrial rocks.

These findings suggest that NWA 13188 experienced exposure to galactic cosmic rays for a significant but relatively short period, potentially tens of thousands of years. Additionally, the presence of a glassy fusion crust implies that the rock melted during a fiery atmospheric entry upon its return to Earth's surface.

Gattacceca and his colleagues assert that these characteristics rule out the possibility of NWA 13188 being a human-made counterfeit meteorite. Consequently, they conclude that the rock is indeed a meteorite, originating from Earth and subsequently re-accreted to its surface.

Mystery Origins of the Boomerang Space Rock

Scientists are puzzled about how this Earth rock ended up in space, speculating that it may have been ejected during a volcanic eruption or propelled by the impact of another meteorite on Earth's surface.

However, the speeds required for a rock to enter orbit are much higher than typical rock velocities, making the volcanic explanation unlikely. Nonetheless, collisions between Earth and large asteroids could potentially launch rocks into the Solar System.

The age of the rock, known as NWA 13188, is unknown, but researchers are working to determine its age by measuring concentrations of a specific argon isotope. Some experts remain unconvinced by the unpublished research, like planetary scientist Philippe Claeys who told Alex Wilkins at New Scientist that there is a need for extraordinary evidence to support extraordinary hypotheses.

The Sahara Desert is an excellent location for meteorite hunting due to its lack of vegetation and the contrasting black stones against the sandy landscape. It is estimated that hundreds of thousands of meteorites could be hidden within the Sahara, making it a prime destination for meteorite enthusiasts and researchers alike.

Notably, previous discoveries have shown that Earth rocks can be found on other celestial bodies, such as the Moon, suggesting that Earth-originating rocks can be launched into space and later re-accreted. This adds to the intrigue surrounding NWA 13188 and its potential origin story.