I was visiting the biltmore estate just outside asheville (north carolina) with my partner on sunday, october 28, 2018. we were awaiting our 2:00pm tour of the home and as we took photos, i focused on the east face of the home to take a vertical photo of the exterior staircase feature's stone carvings. the day was about 65 degrees and the sky was as blue as it could be, so there was no better photography to be had. i used my iphone while my partner took similar photos with his slr (which is charging now so we can pull those photos asap); as we were looking up around 1:30pm, i noticed a funny speck in the sky with a white/silver color, but it was really high (the type of "high" where you know something like a plane at cruising altitude is, for example). it appeared to be a bright or colored slit in the air, akin to the shape of a white/silver "-" dash-like symbol from the keyboard, i suppose. some thoughts in my mind included supernova, missile, weather balloon, etc. i pointed it out to my partner, who wondered aloud about it and continued to move on, taking additional photos. i stood and watched the object with interest and even visually aligned it with a corner of the roof's many features to ensure it wasn't moving, and it definitely wasn't. i stared (literally at this point) for about 7 minutes and suddenly, it just starts moving from about an 80-degree angle (to myself) to an 85/90-degree angle (to myself). for the altitude, i *know* it was moving fast and it took a smoothly arcing curve -- as if along the edge of a circle -- first towards me (east) and then back away (northeast). at this point, i kind of freaked out; i called my partner to come see this and he didn't hear, so i ran to get him. unfortunately, we started looking up and the object was nowhere to be seen, so i lost the opportunity to see the exit pattern it took. i love anything and everything to do with science and space, but this was not something i could explain with any logic or previously known items that it "could" have been.