I don't understand what you mean by curved line. I think the line is actually straight from one point to the other, it's just it's traveling between two mountain peaks.

After the initial impact, it kept traveling forward but went down from the first mountain peak into what is essentially a valley, then out towards the other peak but stopping in the middle. I believe the changes in elevation, give the appearance of curvature, but the line it travels is actually straight. What do you think about that idea?

Also something else I just notice right now. It appears to have some kind of ring around the nose/front end or tip of the object. Measuring distance from the edge of the ring, to the main object, then adding that into the opposite side of the object, makes it roughly 60 feet wide. Also, looking at that ring, makes me think there's more to this object under the snow or ice.