In a surprising move, the Cassini probe was intentionally crashed into Saturn’s atmosphere to prevent contamination from earthly organisms. This decision may puzzle many, as the Huygens probe had actually landed on Titan, one of Saturn’s moons. However, the rationale behind this decision lies in the concerns of astrobiologists and planetary protection experts.
The primary concern of these experts is the potential contamination of Enceladus, another moon of Saturn. Enceladus is believed to have a global ocean of liquid water beneath its icy surface, making it a prime candidate for hosting extraterrestrial microorganisms that may resemble life on Earth. In order to prevent any chance of Earth hardware crashing onto Enceladus and potentially contaminating it, the Cassini probe was destroyed.
On the other hand, Titan, although rich in organic chemicals, poses a lesser risk of contamination. The extremely low temperatures on Titan, around -290 degrees Fahrenheit, are believed to prevent the evolution of Earth-like biology. While ammonia could potentially act as a solvent and basis for membranes on a super-cold world like Titan, the European Space Agency (ESA) considers the risk of contaminating such a cold biosphere to be very low.
The decision to crash Cassini into Saturn’s atmosphere stemmed from the priority of protecting Enceladus, which holds the potential for extant extraterrestrial life. Although Titan is of astrobiological significance, its cold temperatures reduce the likelihood of contamination. By sacrificing Cassini in Saturn’s atmosphere, the NASA-ESA team ensured that the risk of contamination on Enceladus was eliminated.
Source: David Warmflash, Astrobiologist and Science Communicator, Portland, Oregon