It’s not just any scavenger hunt, of course; players will be hunting for suitable parts to build a replica of the Phoenix, the first warp-capable ship flown by a human. Players launch their replica models and compete for the highest altitude, with participants earning holographic memorial vouchers that can be traded in for special engines or holo-emitters. If you’d like to celebrate an achievement that hasn’t actually happened yet, just make sure you’re level 10 by April 5th to take part.
Star Trek Online, First Contact Day matters quite a bit, as it’s the day when humanity first encountered an alien race (the Vulcans, specifically). And now players can celebrate that event from April 5th through the 12th with a scavenger hunt through Bozeman, Montana!
Source: Official Site