Image Caption 1: The orbit of 1950 DA (asteroid 29075) discovered 1950 Feb23 by Carl A. Wirtanen (1910--1990).
Features:
Image Caption 2: A radar image of 1950 DA (asteroid 29075) from the Arecibo observatory, 2001 Mar04.
Yours truly is NOT actually quite sure what we are seeing.
Presumably the horizontal and vertical scales are related to distance on the sky.
Both the download site caption and the Wikipedia caption fail to elucidate the image much.
Why can't we be certain? All those minute astronomical perturbations that can't be accurately included in a calculation that extends for centuries.
What can we do if it's going to hit? A small enough perturbation
early on would deflect it. Just a small push perhaps or just
changing its reflectivity by covering it with charcoal soot.
In fact, 1950 DA's probability
of hitting us will likely change long before
2880 as its orbit becomes
better known: growing maybe, but most likely diminishing to nothing.
So we can all breathe easier so far.