A large Near Earth Asteroid (NEA) makes an approach this week closer than our Moon, and with a little luck and skill, you may just be able to spy it. The object in question is 2005 YU55, an Apollo asteroid about 400 meters in diameter. Discovered in 2005 from the Steward observatory in Arizona, this asteroid is on a 446 day orbit that takes it to a perihelion passage just inside the orbit of Venus at 0.65 Astronomical Units (A.U.) and very near the orbit of Mars at an aphelion of 1.63 A.U. This sets this asteroid up for several close planetary encounters, one of which will occur Tuesday, November 8thas 2005 YU55 passes within 80% of the Earth-Moon distance. The last time an asteroid this large passed our fair planet was the passage of 2010 XC15 in 1976 at 50% the distance to the Moon, but as its name indicates, it hadn’t been discovered yet, and hence that particular passage went unobserved!
