Scientists believe Earth may have briefly lost protection from the sun around two million years ago, left to endure the extreme environment of interstellar space as the solar system passed through a dense cloud of gas and dust between stars.
At that time, early human ancestors shared our planet with prehistoric animals like mastodons and sabretooth tigers. It's also when Earth was in the midst of the ice age that ended only around 12,000 years ago. Ice ages are brought about by a range of factors, including our planet's tilt and rotation, carbon dioxide levels in its atmosphere, and shifting plate tectonics and volcanic eruptions at its surface. However, given the timing of when scientists think Earth plunged through interstellar space, this research suggests radical changes in our planet's climate, like the onset and ending of ice ages, could also be influenced by the position of our solar system in our home galaxy.
