DOUBLE ASTEROID FLYBY: A pair of big, near-Earth asteroids will fly by the Earth-Moon system on Sept. 14th. 2012 QG42 is a 300 meter space rock that comes from the vicinity of Mars; it will pass 2.8 million km (7.4 LD) from Earth. 2012 QC8 is even bigger, about 1.1 km in diameter, hailing from the orbit of Jupiter; it will pass about 8.7 million km (22.7 LD) from Earth. Astronomersmonitoring the incoming space rocks say they are glowing like 14th-15th magnitude stars, which makes them good targets for advanced amateur telescopes. Ephemerides:2012 QG42, 2012 QC8. 1 LD = 384,401 km