so suppose you have two vessels in Interstellar space. One is the ITV Europa while the other one listens to the name ITV Lea Sudux.
Europa is flying at 0.5c, so 149896km/s where as the Sudux chills at 0.8c which is around 239833.6km/s. Both ships fly in opposit directions so they will pass each other. Both ships are more needle shaped and are covered by an Aerodynamic Shield which glows duo to collisions.
Now the question itself is, how would that look ? My main concern here is with Lenght Contraction and the Red Shifting of Light at such speeds. From what i understand, you would only see a Redshifted Univserse with a Shadow wherever the Shield is. The other ship would then maybe just appear as an even more Redshifted spot. But i am not sure. In theory, it might as well just be white. The ships relative velocity to each other is 1.3c, which cant happen. It has appear to be below 1c. At the same time, the relative velocity would be like 99.999999999999999999999999999999999999% of c, which would imply a Maximum Redshift, which would make the other ship appear to be just an ultra bright spot.
So yeah, i am kind of stuck. I think the other ship would appear as a bright spot when it is infront of the other ship and the fade out once it is past. But i am not sure.
Thanks for the help !