It's not new for weird things to be happening at Yellowstone. From earthquakes to rumors about the super-volcano about to erupt, Yellowstone always seems to have something going on. Add to that an increase in reports of UFO's over the park.
If you're not one of Russell Crowe's 825,000 followers on Twitter, maybe you should be. That way you can see a real-time play-by-play of how this whole UFO spotted outside of his office thing plays out.