So after 3 years they can still only narrow down the nearest pass to +/- 4.5 million miles? I really hope something was lost in the writing of the article.
“So after 3 years they can still only narrow down the nearest pass to +/- 4.5 million miles?”
It has to do with other magnetic influences and gravitational pull of other stuff ‘out there’.
For example, the moon and other objects can disrupt the path. That is why their calculations cannot be exact.
This is amazing. The main of error is about 500 times greater than the potential closest approach.
1. In practical terms this means the if the margin of error is too low by 0.2% a direct hit is possible.
2. How is this close encounter going to effect the future trajectory of the asteroid? This is not just a theoretical question. Comet Shoemaker-Levy passed close to Jupiter and on a later even closer orbit broke into pieces and eventually all of them hit the planet. https://en.wikipedia.org/wiki/Comet_Shoemaker%E2%80%93Levy_9
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