[Lonesome in Massachussets]

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

[KarlInOhio]

OK. "Tracked it for three days three years ago" is considerably different from the article's "been able to track it since its discovery, just three years ago." I could see having a pretty big uncertainty in the first case.