Thirty-five years after leaving Earth, NASA has determined that Voyager I left our solar system around Aug. 25, 2012, clocking a total travel distance of over 12 billion miles. Humans, by proxy, have officially begun interstellar travel — Starfleet here we come.

According to the American Geophysical Union, on Aug. 25, Voyager I broke through the heliosphere, a region of space that surrounds our solar system like a bubble of anomalous cosmic rays. Its instruments then became bombarded with galactic cosmic rays, or radiation coming from outside our solar system.

Then Voyager I's plasma wave instrument began to detect something new. Something alien (not invasion alien, just new-to-us alien). Between October 2012 and May 2013 it recorded two instances of interstellar plasma — which is a wicked cool name — vibrations. The sounds are frequencies within human hearing, so just consider this a preview of the things our great-grandchildren will hear on holiday to Alpha Centauri.