Strange White Lines Moving Across Night Sky Late 2000s

I tried looking this one up on Google, but it wouldn't stop yapping about Starlink, so this is my last hope at figuring out what I saw.

I don't know the exact year, but it was probably around 2008 or 2009 when I saw this. I was young and outside at night, and up in the night sky was a large solid white line, slowing crawling across the sky. It stretched from one end of the sky to the other, and I remember it possibly flickering. I pointed it out, but my parents pretty much brushed it off, saying they must be doing something in space. So, does anyone have any idea what I saw?