Author notes

103 - Intimacy Issues

El Cid

on Aug. 17, 2016

I kept going back and forth on whether I liked this page better with or without dialogue.






The Voyager 1 space probe launched from Earth on September 5, 1977. After completing flybys of Jupiter and Saturn, it has continued to hurtle off into deep space ever since. At a distance of over 20 billion kilometers – more than three times further from the sun than Pluto – Voyager 1 is the furthest spacecraft from Earth. So what will be the ultimate fate of Voyager 1? Where will it end up?



Well, Voyager 1 has already traveled pretty far – over 135 astronomical units, which puts it beyond the Kuiper Belt and now outside the sun's heliosphere and into the interstellar medium. But the sun's sphere of influence is gigantic; the Oort Cloud extends to a distance a thousand times greater than the Kuiper Belt, maybe even further. It will take Voyager 1 another 300 years before it reaches the innermost regions of the Oort Cloud, and 30.000 years to make its way through to the other side.



So what then? What lucky star does it end up drifting to? How long does it take? Well, after about 40,000 years in the void, Voyager 1 will have a close encounter with our nearest star – no, not Proxima Centauri. That won't be our nearest star anymore 40,000 years from now. Voyager 1 will pass within 1.6 light years of Gliese 445, a red dwarf that will overtake the Alpha Centauri system as our nearest star because it's approaching us at a speed of about 119 km/sec.

But don't get your hopes up about aliens on Gliese 445 getting their grubby tentacles onto our probe. There are, as far as we can tell, no planets orbiting the red dwarf, and it emits a lot of X-ray radiation, which isn't good for developing lifeforms (or even already-developed ones, for that matter). It's probably a dead zone, and what's more, Voyager 1 won't be stopping there; only passing by. A distance of 1.6 light years is not necessarily too far to get caught in an orbit – some scientists think the sun may have cometary debris in orbit up to 3 light years away – however, objects orbiting that far off need to be moving very slowly in order to remain gravitationally bound (the average orbital velocity of an Oort Cloud object may be only 133 m/s, less than 300 mph). With Gliese 445 approaching at +119 km/sec, and Voyager 1 flying away from the solar system at -16 km/sec, the two will scream past each other at a relative velocity near 135 kilometers per second. Even if it passed really close, that's too fast for Voyager 1 to get caught in an orbit.



So where does it end up going? Will Voyager 1 eventually leave the galaxy? Well… no. Voyager 1 won't end up “going” anywhere, unfortunately. The escape velocity for the Milky Way is approximately 537 kilometers per second. We're orbiting the galactic center at a velocity of about 220 km/s. So Voyager 1 is flying away from us at -16 km/s relative to the sun, which puts it somewhere between 204 km/s and 236 km/s relative to the galactic center. It's not going anywhere. It will end up in orbit within the galaxy, like all the countless stars and rogue planets out there. *Hundreds of millions of years from now, assuming its orbit isn't too drastically perturbed, it could even come back into the vicinity of our solar system, much like planets transiting past each other while orbiting the sun.

In my ongoing tradition of quoting lame Modest Mouse lyrics, the fate of our distant probe reminds me of a line from the song Third Planet:



Tune back in Friday, for the last of our rapid updates. Things will likely slow down a bit after this week.