During a good year for SXSW, attendees can detect a theme to the event after a few days. Maybe it’s 2007, and people suddenly can’t wait to post on something called Twitter, or maybe it’s 2015, and the big revelation is that you can stream live video from your phone without holding it sideways. Perhaps it’s the presence of Barack Obama, the signing of Kendrick Lamar, or the buzzy premiere of Everything Everywhere All At Once. Or, if it’s 2025, maybe it’s aliens. Aliens are all over Austin this year. One of the hottest attractions in the city last weekend was the brand activation for Hulu’s new Alien: Earth, the first television show (created by Austinite Noah Hawley) in 20th Century Studios’ storied Alien franchise, which…