Soot is formed from aggregations of polyaromatic hydrocarbons, which are abundant in space
An interview with one of the earliest scientists working on the project:
The Voyagers are powered by heat from decaying plutonium, which is converted into electricity. Each year, the aging spacecraft lose about 4 watts of power. In an effort to conserve power, the mission team has turned off any systems that were deemed unnecessary, including a few science instruments. Each Voyager spacecraft began with 10 instruments, but now have just three each. The two spacecraft now have enough power to operate for another year or so before engineers are forced to turn off two more instruments.
Some surprising news:
NASA has revived a set of thrusters on the nearly 50-year-old Voyager 1 spacecraft after declaring them inoperable over two decades ago…
JPL reported Wednesday that the maneuver, completed in March, restarted Voyager 1’s primary roll thrusters, which are used to keep the spacecraft aligned with a tracking star. That guide star helps keep its high-gain antenna aimed at Earth, now over 15.6 billion miles (25 billion kilometers) away, and far beyond the reach of any telescope. Those primary roll thrusters stopped working in 2004 after a pair of internal heaters lost power. Voyager engineers long believed they were broken and unfixable. The backup roll thrusters in use are now at risk due to residue buildup in their fuel lines, which could cause failure as early as this fall. Without roll thrusters, Voyager 1 would lose its ability to stay properly oriented and eventually drift out of contact.
Boy, they really built them to last in those days!
I’m really rooting for that little V-Ger!
I wonder if Voyager 1 will still be communicating back to earth then; NASA expects it to.
That’s really cool. I’ll add it to my mental note of “two light-seconds to the moon, eight light-minutes to the sun.”
(Plus my favorite: “two million light years to the Andromeda Galaxy”).
Actually, about 2.5 Mly to Andromeda Galaxy.
Nitpicker! 
(all my figures were approximate).
Point is, if an Andromedan is peering through a super-powerful telescope at Earth right now, they may or may not notice a few apes are oddly walking around East Africa on two feet…
So a slightly longer trip. I’ll pack a couple more audio books.
Hey, that’s what we do around here.
But 2.5 rounds up to 3 as easily as it rounds down to 2. And does it really take that much more memory to remember the “and a half”?
True. I jumped the gun on that one. (The Milky Way and Andromeda galaxies are moving toward each other, so someday my approximation will be more accurate.)
1,000 light years to Omicron-Persei.
The numbers in Monty Python’s Galaxy Song are roughly accurate too, or were when it was written (or so I’ve heard).
Voyager running this long is still incredible. Losing a few instruments hurts, but keeping the core systems alive into the next decade is more than anyone expected. Even with reduced power, the data it sends back will keep teaching us things no other probe can reach right now.