|Discovery date 20 August 2004|
Minor planet category Apollo, NEO, PHA
Discovered 20 August 2004
Discovery site Siding Spring Observatory
Discoverer Siding Spring Survey
|MPC designation (242450) 2004 QY2|
Observation arc 4242 days (11.61 yr)
Absolute magnitude 14.7
Asteroid group Apollo asteroid
People also search for (144908) 2004 YH32
|Discovered by Siding Spring Survey (E12)
0.5-m Uppsala Schmidt|
Aphelion 1.6013 AU (239.55 Gm) (Q)
(242450) 2004 QY2 is a large Apollo near-Earth asteroid and potentially hazardous object. It has a well determined orbit with an observation arc of 7 years and an uncertainty parameter of 0. It was discovered on 20 August 2004 by the Siding Spring Survey at an apparent magnitude of 16.5 using the 0.5-metre (20 in) Uppsala Southern Schmidt Telescope.
Based on an absolute magnitude of 15, the asteroid has an estimated diameter of 3.5 to 7.7 km. 2004 QY2 is one of the largest potentially hazardous asteroids (PHA) discovered. As of 2013 it has the brightest absolute magnitude of any PHA since its discovery. On 29 July 2012 it passed Earth at a distance of 0.4314 AU (64,540,000 km; 40,100,000 mi).
Given the estimated size of roughly 5 km, 2004 QY2 is one of the largest objects to appear on the Sentry Risk Table. It was removed from the Sentry Risk Table on 25 August 2004.