Scientists from the University of Maryland (UM) have reignited the controversy about whether the Voyager 1 space probe, which has been traveling away from Earth since its launch in 1977, has left our solar system and entered interstellar space. Their new study, published this week in The Astrophysical Journal Letters, argues that the spacecraft departed the solar system more than a year ago on July 27, 2012. The dauntless Voyager 1 spacecraft currently is traversing a little-known region of space some 11 billion miles (18 billion kilometers) away from its home planet.

The results of the UM study run counter to recent papers published by NASA scientists finding that Voyager 1 has only made it as far as the edge of the heliosphere–that region of space surrounding the Sun that teems with charged particles and is dominated by the solar magnetic field.