and that an amateur spotted it
How much are we paying that guy vs the pros? The same ones who tell us there the ones they are tracking are low threat.
More than a few folks keeping an eye out to catch what they can
http://spacewatch.lpl.arizona.edu/
http://asteroid.lowell.edu/asteroid/loneos/loneos.html
http://asteroid.lowell.edu/asteroid/loneos/loneos.html
and on and on. Quite the group.
It would appear that Jupiter lacks such groups....