We've talked about the Voyager 1 spacecraft in the past, and it's most known for being the farthest man-made object from the Earth, and it's been announced that the 1,600-pound space probe has exited our solar system, as well as the heliosphere beyond the influence of the Sun. However, the probe has been experiencing drastic changes in radiation levels since leaving the solar system.
It's said that back in August, levels of galactic cosmic rays, which is cosmic radiation from outside of the solar system, spiked to levels that haven't been seen since Voyager's launch back in 1977. It was reported that radiation levels spiked by twice as much as they previously were. However, since leaving the solar system, scientists that the intensity has decreased but the cosmic ray levels are still high.
However, many astronomers and scientists are arguing whether or not Voyager 1 has reached interstellar space or simply just entered a separate, undefined region that's located beyond the solar system. Bill Webber, professor emeritus of astronomy at New Mexico State University, argues that Voyager 1 is "outside the normal heliosphere" as we speak, which means that the spacecraft has entered interstellar space.
So far, Voyager 1 has been active for 35-and-a-half years, and it's still communicating with NASA, making it the oldest spacecraft to still be active. The probe's primary mission officially ended in November 1980 after it successfully explored Saturn and Jupiter, as well as both of the planets' various moons.