This latest rock was discovered by Pan-STARRS on 2015 October 10. It is an Apollo-type object which means its orbit crosses Earth’s orbit. They reckon it is c.500 metres across and is in a short-period (3 year) highly elliptical comet-like orbit tilted 40 deg to the ecliptic.  Maybe it is a gassed-out comet nucleus. It passes us within 1.27 lunar-distances today, October 31 at 17:00 UT. The best chance to see it was last night, Friday October 30/31. I found it quite easily half an hour before midnight, in Orion at its predicted 12th magnitude, and followed it for half an hour. I got the orbital parameters from http://ssd.jpl.nasa.gov/horizons and plugged them into my Megastar software (2002 vintage). The picture is of the Megastar chart with the track of the asteroid marked, using the JPL data.  I have written on the chart what I actually saw. You can see the track is shifted slightly north and the asteroid was running a few minutes behind schedule.  I don’t know for sure why there is the small discrepancy between calculated and actual positions. I guess it is due to some parallax effect due to the asteroid’s proximity.