All good things must come to an end. The Cassini mission, which involved sending a probe to Saturn to gather data on the gas planet and its system of moons, reached its conclusion earlier today. After what was deemed to be a smashing success, NASA ended things with a smash, crashing the probe into Saturn.
— NASA (@NASA) September 15, 2017
As odd as it seems to crash a working probe into a planet, NASA had pretty good reason. Cassini had finally met (and arguably exceeded) its lifespan, and with fuel reserves running low, NASA needed to decide whether to let the probe drift or decide its fate. Knowing it wasn’t coming home, NASA decided to destroy the probe by sending it into Saturn, where it would burn up while entering the atmosphere of the gas giant. Being a gas giant, NASA figured the stakes were low — Saturn doesn’t have much of anything that would make us think there’s any sort of life floating about. Saturn’s moons are a different story, and NASA wanted to make sure that they didn’t in negligence contaminate any of them with probe bits. After all, in April of this year NASA revealed the possibility that one moon, Enceladus, could have a subterranean ocean capable of supporting life. How did they know? Data from none other than the Cassini probe, of course!
The Cassini-Huygens probe got its start 20 years ago, when it was launched into space on October 15, 1997. The probe was activated two years later, and flew past Earth, Venus, and Jupiter before finally entering into orbit around Saturn in 2004. The mission, a joint venture between NASA and space agencies from Europe and Italy, was extended several times as Cassini kept right on delivering huge payloads of data about Saturn and, more importantly, its fascinating moons. Those moons remain the most likely source of extraterrestrial life within our own solar system, something we only know because of the Cassini probe.
NASA tweeted out the final moments of the probe as it was on course to collide with Saturn’s atmosphere this morning. The probe may be gone, but we’ll always have its Twitter account.