Astronomers have confirmed that a suspicious space rock that hit Earth in 2014 came from another star system, predating the famous ‘Oumuamua by three years. Researchers found the meteor in the catalogue of NASA’s Center for Near Earth Object Studies (CNEOS) in 2019. At that time, some of the data about the rock’s trajectory was kept secret by the US Department of Defence (DoD), whose sensors collected them. But in March this year, the DoD released a statement confirming the measurements, allowing scientists to complete their calculation of the mysterious rock’s origin. The 0.9-metre (2.9-foot) wide mini-asteroid, which entered Earth’s atmosphere on 8 January 2014, arrived at a very fast speed of 215,974 kilometres (134,200 miles) per hour. It also followed an odd trajectory that suggested it may have come from outside the Solar System. By modelling the rock’s path into the past, the authors of a new paper confirmed the tiny asteroid was indeed a newcomer into the Sun’s corner of the Milky Way.
The confirmation makes the rock, named CNEOS 2014-01-08, the first known visitor from interstellar space, predating the asteroid ‘Oumuamua that zipped past Earth in 2017. Only one year later, astronomers discovered the second interstellar object, the 0.5-kilometre (0.3-mile) wide comet Borisov. The short interval between those discoveries led astronomers to believe that smaller interstellar rocks, only a few metres wide, must be much more common in the Solar System and even regularly cross paths with our planet.