While the planets in on our solar system orbit the sun, the solar system itself is traveling through space. Earth and our Sun has been traveling through the Local Interstellar Cloud for somewhere between 40,000 and 150,000 years. So far, the journey has been quite peaceful. But astronomers warn of turbulence ahead, caused by a shift in direction of helium atoms that flow into the solar system. If the shift continues this way for thousands of years, it could be a harbinger of more dramatic changes in our solar system, David McComas for the Southwest Research Institute told Science Magazine.
If the forecast is true, it could signal a change in the heliosphere, the bubble that protects our solar system from harmful cosmic rays. The heliosphere is made of charged particles which are blown out from the sun by the solar wind. The size and shape of the heliosphere are both determined by the outward push of the solar wind and the inward pressure from gas in the Local Interstellar Cloud.
To detect the wind shift, researchers studied measurements of 11 spacecraft and satellites. According to Priscilla Frisch of the University of Chicago, helium is a particularly strong tracer for atoms infiltrating the heliosphere because it is abundant and survives in its atomic state through the journey. So far, the change in direction over the course of four decades has only been between 4 and 9 degrees. But if this continues to shift direction over time and ultimately flips to the other side of the solar system, the heliosphere will be distorted. And that could mean more harmful galactic cosmic rays making their way to Earth.
According to McComas, even having the ability to detect and record changes in the solar system’s environment “is a really big deal.”
Source: Science Magazine, Daily Galaxy