Farscape/Recap/S01 E02 IET

Season 1, Episode 2:

I, E.T.
A Peacekeeper beacon is activated on Moya that threatens to lead Crais' command carrier straigth to their location. In order to muffle the signal, Crichton suggests they fly into the atmosphere of a nearby planet and submerge Moya in a bog, stifling the signal until the beacon can be removed. However, the beacon is attached to some of Moya's neural networks, meaning a dangerous operation must be performed in order to destroy it. Crichton, Aeryn and D'Argo go out onto the planet to get an anaesthetic: chlorium, an commonly occuring element that can numb Leviathans in large amounts.

It transpires that the planet's population are culturally similar to the people of Earth, and they've never met aliens before. Crichton meets a woman and her son who've spent their lives trying to make first contact with aliens, while D'Argo falls into the hands of the planet's military, who think he's a threat and want to study him. Once Crichton has found a large enough source of chlorium (in the seasoning), he helps D'Argo escape, they take it back to Moya, and Rygel and Zhaan remove the beacon.