astro.wikisort.org - Asteroid

(458732) 2011 MD₅ is an Apollo near-Earth asteroid around 1.2 kilometers (0.75 miles) in diameter. It is the largest asteroid known to have passed closer than the Moon.[4] On 17 September 1918 the asteroid passed 0.00234 AU (350 thousand km; 0.91 LD) from Earth[3] with a peak apparent magnitude of around 8.4. The 1918 close approach distance is known with an accuracy of roughly ±200 km. The asteroid had come to opposition (opposite the Sun in the sky) on 9 August 1918 at magnitude 16.

(458732) 2011 MD₅

Discovery[1][2]
Discovered by	Pan-STARRS 1
Discovery site	Haleakala Obs.
Discovery date	30 June 2011
Designations
MPC designation	(458732) 2011 MD5
Alternative designations	2011 MD5
Minor planet category	NEO Apollo[2][3]
Orbital characteristics[3]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc	8.67 yr (3,165 d)
Aphelion	3.9869 AU
Perihelion	0.9895 AU
Semi-major axis	2.4882 AU
Eccentricity	0.6023
Orbital period (sidereal)	3.92 yr (1,434 d)
Mean anomaly	49.188°
Mean motion	0° 15m 3.96s / day
Inclination	10.553°
Longitude of ascending node	170.34°
Argument of perihelion	224.84°
Earth MOID	0.0627 AU (24.4 LD)
Physical characteristics
Mean diameter	730–1600 m (CNEOS)[4] 0.8 km[5] 1.2 km
Absolute magnitude (H)	17.8[3] 17.9[2]

2011 MD₅ was not discovered until 30 June 2011,[1] when the asteroid was 1.3 AU (190 million km) from Earth. The asteroid now has a 8 year observation arc and a well determined orbit.

References

External links

• (458732) 2011 MD5 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
• (458732) 2011 MD5 at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical Properties · Summary
• (458732) 2011 MD5 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

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