It’s been six months since NASA’s Voyager 2 spacecraft left the protective bubble around our solar system known as the heliosphere and officially crossed into interstellar space, marking the second time ever a human-made object has traveled so far.
Voyager 2 followed in the footsteps of its predecessor, Voyager 1, and both craft will eventually be joined in the ‘space between the stars’ by the Pioneer 10, Pioneer 11, and New Horizons missions.
While all will run out of fuel and die, and Earth will lose contact with the craft (for those of which it hasn’t already), they could continue to drift farther and farther into deep space for thousands or even millions of years.
Scientists have now calculated where they expect each of these craft to end up throughout the course of their respective journeys, starting with our nearest stellar neighbor, Proxima Centauri.
Notably, Voyager 1 will then travel on to a very close encounter with the star TYC 3135-52-1, roughly 46.9 light-years from the sun, and eventually to Gaia DR2 2091429484365218432, which sits 520.22 light-years away – but, it will be 3.4 million years before it gets there, according to Space.com.
In a new study published in the journal IOPscience, a duo from NASA and the Max Planck Institute for Astronomy in Germany attempted to plot the close approaches Voyager 1 and 2 and Pioneers 10 and 11 will eventually make in interstellar space.
For all but one, Proxima Centauri will be the first flyby – though this won’t come for many thousands of years.
Voyager 1 will pass the star in about 16,700 years, though from a faraway distance of about 3.59 light-years away, followed by Pioneer 11 in 18,300 years and Voyager 2 in 20,300 years.
Pioneer 10, on the other hand, will first fly past the small star Ross 248, roughly 10.3 light-years away.
Calculating the path of these craft so far in the future is no simple task, and the team built upon methods they previously used to trace the possible origin of the mysterious interstellar object ‘Oumuamua.
‘Although they will cease to operate long before encountering any stars (the Pioneers already have), it is nonetheless interesting to ask which stars they will pass closest to in the next few million years,’ the researchers explain in the paper.
‘We answer this here using the accurate 3D positions and 3D velocities of 7.2 million stars in the second Gaia data release (GDR2, Gaia Collaboration 2018), supplemented with radial velocities for 222,000 additional stars obtained from Simbad.’
While there are some uncertainties, the researchers were able to narrow down the trajectories to make note of the stars each craft will come relatively close to, within 15 parsec (about 50 light-years).
In some cases, the scientists expect the craft to get within 1 pc of certain stars, or a distance of just over 3 light-years. All of these encounters, however, will occur far in the future.
Voyager 1 is expected to come within 0.3 pc, or less than 1 light-year, of the star TYC 3135-52-1, which sits roughly 46.9 light-years from the sun.
This flyby will occur about 302,700 years from now.
It will also make a close approach of Gaia DR2 2091429484365218432 in about 3.4 billion years, coming within about 1.27 light-years.
The research highlights the extreme journeys these craft will make as they press on long beyond even our own lifetimes.
‘It was mostly a bit of fun,’ author Coryn A. L. Bailer-Jones, of the Max Planck Institute for Astronomy told Space.com.
‘But it also reminds us how long it takes to get to nearby stars at the kind of speeds these spacecraft have achieved (around 15 km/s relative to the sun).’