Tsunamis

One might have expected NASA’s Voyager 1, the first man-made object to leave the solar system, would have nothing but quiet, peaceful sojourning ahead of it. But it’s actually been a rather bumpy ride. Voyager has recently rode out three “tsunamis,” massive interstellar shockwaves that spread through space. Scientists measured the first shockwave from October to November 2012. The second was from April to May of 2013. And the third started in February of this year and is still going on. The waves are actually caused by our sun, still influencing Voyager even though it’s 19 billion kilometers away. A coronal mass ejection, which pushes a magnetic cloud of plasma from the sun’s surface, generates a pressure wave. When this pressure wave hits interstellar plasma (charged particles between the stars), it creates a shockwave through that plasma. “The tsunami causes the ionized gas that is out there to resonate — ‘sing’ or vibrate like a bell,” said Ed Stone, project scientist for the Voyager mission based at California Institute of