Location of NEO 2012 QG42 as seen from Mayhill New Mexico on September 14 at 11:08 pm (05:08 UT). The tick intervals are every 5 hours Click to embiggen.
Near Earth Object 2012 QG42 is a recently discovered relatively bright NEO. This NEO is in an excellent position for observation compared to our previous ones over the last month.
2012 QG42 is a 375 metre diameter rock that will be 7.4 Earth-Moon distances from us at closest approach. It is closest on September 14 at 05:08 UT.
It will be well placed for observation from both New Mexico and Spain at closest approach, being reasonably high in sky in Hercules. At closest approach it will be around magnitude 14.1, so reasonably easy to capture with modest exposure times and not too much smearing.
The asteroid will be brighter before closest approach due to the apporach geometry, it comes within 10 LD on the 10th (UT), and is quite bright 13.7-13.6) for some time. Astrometry and photometry has been requested so the Arecibo telescope can do radar measurements.
Location of NEO 2012 QG42 as seen from Mayhill New Mexico on September 14 at 11:08 pm (05:08 UT). The rectangle is the field of view of T5 and the tick intervals are every 15 seconds. Note the parallax difference bewten the calculated position and the orbit. Click to embiggen.
Like other recent fast moving NEOs this asteroid is close enough that a planetarium program will have substantial parallax error so it will be best to use topocentric coordinates. For topocentric ephemerides go to
Spain MPC Code I89, Nth America MPC Code - H06
Always use the latest possible orbital elements and ephemeris, as the orbit is still being refined. The planning guides to viewing YU55 here and here will help organising topocentric ephemerides for these events.