Voyager 2 Will Soon Be The Second Man-Made Object To Reach Interstellar Space

Voyager 2 Will Soon Be The Second Man-Made Object To Reach Interstellar Space
Image: NASA/JPL-Caltech

It’s astounding to think that both Voyager probes, launched back in 1977, are not only still intact, but sending valuable data back to Earth. It wasn’t long ago that Voyager 1 entered interstellar space, leaving the solar system’s protective heliosphere. Soon, Voyager 2 will join it, with the probe’s sensors detecting a gradual increase in cosmic rays over the last few months.

Voyager 2 has travelled over 17.7 billion kilometres since leaving Earth, according to a recent story from NASA’s Jet Propulsion Laboratory (JPL). That sounds like a fair distance… until you convert it to light years, where it’s a piddly 0.0018.

Still, it’s a remarkable achievement and, judging by growing cosmic rays — about a five per cent increase over two months — it’s only a matter of time before the probe joins its companion in interstellar space.

Unfortunately, because of the nature of the heliosphere, pinning down an exact date is difficult:

…Voyager team members note that the increase in cosmic rays is not a definitive sign that the probe is about to cross the heliopause. Voyager 2 is in a different location in the heliosheath — the outer region of the heliosphere — than Voyager 1 had been, and possible differences in these locations means Voyager 2 may experience a different exit timeline than Voyager 1.

Not that there’s any rush, really. The probe has been rocking space for over 40 years, I’m sure a couple more won’t make a difference.