The Thargoids started showing up in Elite: Dangerous back in January, interdicting players in their hyperspace travels and (apparently) scanning their vessels. Now they're showing up on planetary surfaces, and the encounter is just as eerie.
YouTuber ObsidianAnt provides this start-to-finish look at the Thargoids' flower-shaped vessel arriving at a "barnacle" on a planet in the Pleiades sector. (Coordinates are in the about section on the YouTube page.) Barnacle appearances have coincided the Thargoid sightings, but no one really knows what they mean, either.
In the encounter, which some theorize is triggered by going out in a surface vessel and scanning a barnacle, the player's vehicle loses power, the game takes over, and the startling cinematic unfolds. The Thargoids' ship seems to be extracting something from the barnacle. Some have guessed this is a refueling stop for the aliens.
Pursuit attempts, as they have since January, still fail, though the ship still leaves a hyperdrive wake that players may scan.
There's no official news post about this — it would kind of spoil the mystery if Frontier Developments gave one, right? The last update for Elite Dangerous came near the end of April. Speculation as to what the 2.4 patch entails has centered on the Thargoids since December.
The Thargoids don't do anything hostile — yet — but that doesn't mean they aren't a threat. They've appeared in previous Elite games (which date to the 1990s) and when Elite: Dangerous was crowdfunded back in 2012, developers said the insectoid race is still around, and would eventually show up in this game.