While flying from Los Angeles Angeles to the United Kingdom I was watching out the window because I couldn't sleep. We were flying around 33000 feet heading over Canada towards Greenland and around the pole. Even though it was late at night local time the light from the sun could still be seen in the sky and it created a kind of twilight effect with the red glow on the horizon. I noticed on the Starboard side of the aircraft a darker shape below us in the cloud cover. It looked like a circle and so I grabbed my phone to grab a picture and video. By the time I had turned back I was having difficulty pinpointing the UFO Sighting with my phone camera. Just then I noticed a second stationary UFO ahead of it in our same travel direction. We were flying at roughly 33000 feet and my best guess would place the 2 UFO Sightings at about 28-K-30-K-ft so slightly below us. The second UFO Sighting was much more noticeable because I think we were closer. It looked like a flying saucer with a dome shape in the middle of the UFO. Silver in color it stood out against the white of the cloud cover behind it. The UFO saucer was just sitting there not moving. There were no lights on it, no markings. It just hovered there as we passed by. I have not girlfriend look out the window so she could see it. I was able to get video but the turbulence of the aircraft made it a tad difficult to focus and the camera zoom isn't the greatest. My eyes on it confirmed it was there. Regardless of the video I saw it and would testify it was a flying saucer Hovering there with other one at roughly the same altitude but further from our plane. These UFOs were both just hovering there, no movement, no lights.