A Piece of Cassini Escaped Destruction and Disappeared
You can't keep a good probe down.
Despite ending its twenty year career by being thrown into the crushing gravitational force of the planet Saturn, the Cassini space probe lives on - at least, in part. It turns out that this particular robotic explorer is especially difficult to kill, having jettisoned a Harry Potter-style horcrux of sorts that escaped destruction, and has now disappeared.
The part of Cassini that still exists isn't an essential piece of the probe, or anything that's still usable - instead, it's a cover for the Cosmic Dust Analyzer (CDA) that was present on Cassini's body. During launch, the CDA was shielded with a piece of aluminum which got detached and discarded before the probe began its journey to Saturn in earnest.
While this is only a small piece of the probe, and something that was always designed to be disposable, the aluminum cover is still out there in the solar system somewhere - even though nobody knows exactly where. The cover is likely in a vague orbit around the sun, traveling at a swift nineteen miles per second on a free and loose journey.
When our mission to Saturn came to an end, Cassini became part of the planet itself. But one metallic piece survived the mission, and is still traveling through space. Learn more: https://t.co/FXN4tFYiog #SaturnSaturday pic.twitter.com/AWljmhdli0— CassiniSaturn (@CassiniSaturn) December 23, 2017
Some computer models from NASA also speculate that the cover could be drifting around between Venus and Earth. If such models can be believed, then in 2007, the cover traveled most of the way back home, reaching within 2.5 million miles of planet Earth. This would hardly be visible to the naked eye, but it's possible that it could potentially show up on the sensors of powerful orbital telescopes, if only by complete accident.
Considering the large number of conspiracy theorists who are eager to claim that any anomaly in space is a sign of imminent alien invasion, it's worth remembering that there's plenty of stuff floating around up there that could easily look like a Martian warship to the untrained eye. So if this piece of Cassini did come back home, hopefully it didn't scare anyone watching the skies.
There's something wonderfully comforting about the idea of a piece of Cassini managing to escape death in the fiery atmosphere of the planet Saturn. This probe worked tirelessly over twenty years to provide us with some of the best data and photographs of Saturn and its moons that we've ever seen, and it's nice to know that it's not entirely gone.
That said, the dust cover is, to a certain extent, a liability. Cassini was destroyed because it might have carried Earth bacteria which risked contaminating the environment on another world. If the cover contains any of these micro-organisms, they could have mutated over the past couple of decades. By this point, the probe cover could pose a threat to life on Earth were it to ever find its way back in one piece - something that's not entirely impossible, considering that mysterious bacteria have been found on the outside of the International Space Station.
Nevertheless, let's all remember Cassini for its fantastic contributions to science. Much like the Shroud of Turin, the probe's former covering remains out there somewhere, as a constant reminder of what marvelous things mankind can achieve when we strive to learn more about the universe.