Very slow moving craft with red and green lights accelerating at incredible speed.

June 7th 2021 Marietta, OH. approx. 9:00 pm  I was looking to the SSW right before dark and noticed a green and red flashing light just above the neighbors house. The cloud cover was very low so the object was not very high in the sky. The object never made any sound and traveled so slow at times I thought it was hovering. I watched it for 12 to 15 minutes. It was traveling NNE like it was following the Ohio River. I kept trying to figure out what is was, not a plane(too slow) and the strobe period is not right(too slow), maybe it's a blimp. Yeah, it's a blimp because I can see shape of the lights like on a billboard. Maybe it will turn up the Muskingum River like it was heading towards Akron. Instead it kept going in the same direction, slowly getting closer. The lights were a circle of red lights with one being a vertical square bar on top. The green lights were arranged in a triangle with a long horizontal green bar on the bottom and individual lights on the sides (see Fig. 1). Flashing red then green, red then gree! n. With no warning the object took off at incredible speed to the East(see Fig. 2). It was so fast that I think my eyes blended the red and green lights into a yellow streak . Never have I seen anything like that, so I thought I should report it.