Astroid to Strike Earth in 2007

For what it is worth, the think tanks around the world who are
attempting to solve this problem by means of knowing precisely the time
and location of impact will never be accurate. The equation can not be
figured out for many factors. Factors- How much matter it is losing, how
the speed will increase and decrease due to gravitational changes, and
the effects of the expansion of space in the Universe as we know it. It
will be important to know in order for us to start thinking about what
measures of reactions we will take based on the site of impact (land or
water/glacier state). Any shared equations and information will be
appreciated. Thank You. BR