UFO Sighting in Anoka, Minnesota on 2017-07-29 21:30:00 - Distant dark object observed in arc from ssw to wnw over eight second flight path

We were sitting on front porch of my apartment eating and listening to the starborn connection radio show on kgra when my girlfriend noted a distant object in the sky about 30 degrees elevation to the south south-west. we thought it was either a bird or airplane but there was no sound, no lights, no flapping of wings. the object traveling in a smooth movement from east to west when we first saw it. as we watched, we debated whether it was a bird or aircraft. i initially thought it was an eagle soaring over the mississippi river, near my apartment. we continued to watch it as it moved and slowly curved its flight path toward the north. we also noted that it was near dusk and we wondered if it were an airplane, whether it would have lights visible. we eventually lost sight of it in the tree line along the river. total sighting time was about eight seconds. note: it was about 30 minutes into the show, so we estimate it was probably at about 9:30 pm cdt. the sun was down and there was a partial moon visible. weather was clear, with a few scattered high cirrus clouds in the sky.