The Solar System has always been as tranquil as scientists once thought, traveling through the emptiness of space as a lone, remote island of rocky bodies. Now, they have discovered that around 70,000 years ago, the Earth’s home was visited by a small binary star system. Scholz’s star, as they have named it, traveled within just one light-year from the Sun, which struck the boundary of the Oort Cloud, where most comets reside, just as humans were migrating from Africa.
At this point in the Earth’s history, both Neanderthals and anatomically modern Homo sapiens were wandering about the Earth in their hunter-gatherer tradition. Around this time of evolution and the creation of near-prehistoric tools, the formation of language, cave paintings, and the discovery of fire, a second bright light in the sky appeared at the edge of the Solar System, just beyond the former ninth planet, Pluto.
Though, as could be expected, the early ancestors of modern humans were most likely not in tune with the cosmos enough to notice the bright binary system just above the horizon. The binary system at the edge of the Solar System traversed just beyond the Oort Cloud. The Oort cloud is the cloud of icy rock that creates the spherical circumference that harbors the Solar System. In the cloud lies nearly all comets that have passed within view since humans began to notice them, a few millennia ago. They are stuck just within the outer reaches of the Sun’s gravity.
The transient star would have come within just under one light-year from Earth, about 52,000 astronomical units (AU), one AU being the measure between the Sun and the Earth. This study was published in the Astrophysical Journal Letters.
To surmise how close Scholz’s star passed within the Solar System, the nearest star to the Solar System that scientists have identified is Proxima Centauri – a measly 4.2 light-years away from Earth. Scholz’s star was never going to be a part of the Solar System, it was only passing through. The binary star system moved through the Oort Cloud and is now located around 20 light-years from Earth.
As the binary star system moved through the outer reaches of the Solar System, in the Oort Cloud, the star system could have possibly disturbed trillions of small comets and other icy, rocky stellar bodies that were drifting in the area, potentially jolting them out of their constant orbit and pelting the inner Solar System with a plethora of comets and small asteroids. This was not the best scenario regarding the Earth, considering it is the only known planet in the Universe so far that harbors intelligent life.
Scientists have now embarked on a project to monitor incoming asteroids and comets to make sure that the Earth is safe from a potential global killer. The European Space Agency (ESA) has recently launched what they called the Gaia satellite which is used to track and map the locations and relatively velocities of over a billion stars, giving astronomers a better sense of which stars, if any, have visited the Solar System and when. Moreover, they are attempting to track potential incoming stars that may buzz the edge of Oort Cloud once more, giving people a clear warning before such an event happens since Scholz’s star came to the Solar System 70,000 years ago.
By: Alex Lemieux
Picture: NASA Goddard Space Flight Center/License–