Voyager II, old and faraway spacecraft will become a silent witness of the Earth civilization

NASA engineers have turned off a heater on Voyager 2 because of the continually shrinking power supply facing each of the spacecraft on their odysseys. The heater in question is paired with an instrument called the cosmic-ray subsystem instrument, which is still sending data back to Earth even at its new ambient temperature of minus 74 Fahrenheit (minus 59 Celsius). Engineers have also fired up a long-dormant thruster system on the aging spacecraft.

"The long lifetimes of the spacecraft mean we're dealing with scenarios we never thought we'd encounter," Suzanne Dodd, project manager for the Voyager mission at NASA's Jet Propulsion Laboratory in California,  said in a statement. . "We will continue to explore every option we have in order to keep the Voyagers doing the best science possible."

Voyager 2 is a space probe

launched by  NASA on August 20, 1977, to study the outer planets. Part of the Voyager program, it was launched 16 days before its twin, Voyager I, on a trajectory that took longer to reach Jupiter and Saturn but enabled further encounters with Uranus and Neptune- It is the only spacecraft to have visited either of these two ice giant planets.

Its primary mission ended with the exploration of the Neptunian system on October 2, 1989, after having visited the Uranian system in 1986, the Saturnian system in 1981, and the Jovian system in 1979. Voyager 2 is now in its extended mission to study the outer reaches of the Solar System and has been operating for 41 years, 10 months and 19 days as of 9 July 2019. It remains in contact through the NASA Deep Space Network.

At a distance of 120 AU (1.80×1010 km) (about 16.4 light-hours) from the Sun as of February 25, 2019,[7] moving at a velocity of 15.341 km/s (55,230 km/h) relative to the Sun, Voyager 2 is the fourth of five spacecraft to achieve the escape velocity that will allow them to leave the Solar System. The probe left the heliosphere for insterstellar space on November 5, 2018, becoming the second artificial object to do so, and has begun to provide the first direct measurements of the density and temperature of the interstellar plasma.

Ref.: space.com and wikipedia