NASA’s Voyager I spacecraft may soon become the first man-made object to leave our solar system, but NASA officials say it’s too soon to call it.

Voyager 1 transmitted this first-ever image of the Earth and moon. | (Photo by NASA/National Geographic/Getty Images)

In August of 2012, a report in the Geophysical Research Letters journal suggested that Voyager I had moved beyond our sun’s heliosphere – a protective bubble of charged particles created by solar winds that protects our solar system from intense galactic rays. The journal article reported that Voyager I, which is now 17 billion miles away from our sun, recorded a sudden doubling of cosmic radiation. This dramatic reading seemed to suggest that the probe had moved beyond the protection of solar winds.

However, Voyager mission specialists say that Voyager I has not yet left the heliosphere and entered interstellar space. Instead, they say, the probe has entered a newly discovered region of space dubbed “the magnetic highway”. This region seems to be a  boundary between our solar system and interstellar space. Though the number of charged particles in this region increased dramatically according to readings from Voyager I, mission specialists say these particles are still under the influence of our sun.

NASA officials, however, believe Voyager I is close to escaping solar influence. A radical change in the direction of magnetic readings would be the first indicator that the probe had truly entered interstellar space, they say.

Voyager I was launched on September 5, 1977 to study the outer solar system and interstellar medium. Photographs and readings from Voyager I and its sister craft, Voyager II, have dramatically increased our knowledge of the other heavenly bodies in our solar system. Both Voyager I and II carry a gold plated audio-visual disc containing information about Earth and her inhabitants, including a recording of Chuck Berry's "Johnny B. Goode". The disc was included as a gift and greeting in the event that any intelligent life forms should find the probes.