Huygens probe
On January 14, 2005, Cassini that had travelled all the way to Saturn deployed ESA’s Huygens probe, bound for landing on Saturn's moon Titan.
Before this, very little was known about the surface of Titan, other than it had a thick nitrogen atmosphere (the only one similar to Earth in that respect) and that there was the potential for seas of methane to exist on its surface.
Huygen found a much more dynamic world that had been imagined, with river flow channels and dry lake beds, not of water, but Methane. Towards the poles Methane lakes did indeed exist, so much so, the sun would glint from them occasionally.
At it’s hottest point, Titan is a chilly -173.6 °C , however, models have suggested that when our Sun expands into a red giant, it could heat up towards around -50 °C, which is actually warmer than the lowest temperature ever recorded in Yellowknife, Canada (−51.2 °C ).
Titan will almost certainly be attracting more missions, currently NASA has a mission called Dragonfly, slated for 2026 with arrival in 2034.
https://www.nasa.gov/press-release/nasas-dragonfly-will-fly-around-titan-looking-for-origins-signs-of-life
