As Earth and the other planets orbit the sun, the solar system itself travels through space. Its slow journey is taking it though a wispy expanse of gas called the Local Interstellar Cloud. Now, astronomers have discovered signs of potential turbulence in the cloud, indicated by a shift in direction of helium atoms that flow into the solar system. If the shift is real and continues for hundreds to thousands of years—a dicey extrapolation—it could be a harbinger of more dramatic changes in our solar system, notes study co-author David McComas of the Southwest Research Institute in San Antonio.
