Go here: http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2013TX68;cad=1
There were a total of 32 observations, between October 6, 2013 and October 9, 2013. That’s a tiny database and a very short timeline to extrapolate its orbit forward two and half years. As of today, the uncertainty in orbital period is two days. The earth moves in its orbit 30 km/sec, the uncertainty in the position of the earth over two days in more than 5,000,000 km, all of which adds to the uncertainty in position of asteroid relative to the earth. After this pass, we should have a much firmer grasp of it’s orbit because of the two year baseline.
# obs. used (total) 32
data-arc span 3 days
first obs. used 2013-10-06
last obs. used 2013-10-09