is a bright, sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid (PHA) of the Aten group, located in Venus's zone of influence that has frequent close encounters with Mercury, Venus, and Earth. It made a close approach to Earth on 11 December 2015, passing at a distance of about 4.2 million kilometers (2.6 million miles, 11 lunar distances) and reaching about apparent magnitude 11. The asteroid was discovered on 25 November 1998 by LINEAR about four months after a close encounter with the planet Mercury (about 0.047 AU). It measures approximately 400 meters in diameter. It is also one of the best studied PHAs and was the 10th Aten asteroid to be numbered. Classification and orbit orbits the Sun at a distance of 0.42–1.02 AU once every 7 months (222 days; semi-major axis of 0.72 AU). Its orbit has an eccentricity of 0.42 and an inclination of 7° with respect to the ecliptic. Low aphelion At the time of its discovery, astronomers were trying to find the first Apohele asteroid (one that is always closer to the Sun than Earth). All asteroids known at the time that got closer to the Sun than Earth also crossed Earth's orbit. Earlier that year, David J. Tholen claimed to have spotted the first Apohele asteroid, which was dubbed . However, the object was lost without being confirmed. Thus, 1993 DA remained the asteroid with the lowest known aphelion at 1.023 AU. When was discovered, it was found to have a slightly smaller aphelion (1.019 AU) than 1993 DA, and was thus the closest thing to an Apohele asteroid known at the time. It lost its smallest aphelion title almost immediately when was discovered only a few weeks later (aphelion = 1.014 AU). Asteroids with even smaller aphelions were discovered until February 2003, when finally, an asteroid with an aphelion smaller than 1.000 AU was discovered. This was 163693 Atira, the first confirmed Apohele asteroid. Venus zone of influence was the second asteroid discovered to be close enough to Venus as to be within the major planet's zone of influence. It is located at about the inner edge of the zone, while (99907) 1989 VA, the first asteroid discovered there, is at about the outer edge. It is possible for planets to capture asteroids located in their sphere of influences into co-orbital relationships such as Trojan and horseshoe asteroids. Because of its