astro.wikisort.org - Asteroid

(101869) 1999 MM, provisional designation 1999 MM is a sub-kilometer asteroid on an eccentric orbit, classified as a near-Earth object and potentially hazardous asteroid of the Apollo group. It was discovered on 20 June 1999, by the Lowell Observatory Near-Earth-Object Search (LONEOS) at its U.S. Anderson Mesa Station in Flagstaff, Arizona. The first observation was made by Catalina Sky Survey just 8 days before its official discovery.[2]

(101869) 1999 MM

Discovery[1]
Discovered by	LONEOS
Discovery site	Anderson Mesa Stn.
Discovery date	20 June 1999
Designations
MPC designation	(101869) 1999 MM
Alternative designations	1999 MM
Minor planet category	Apollo · NEO · PHA[1][2]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	8.67 yr (3,167 days)
Aphelion	2.6168 AU
Perihelion	0.6319 AU
Semi-major axis	1.6243 AU
Eccentricity	0.6110
Orbital period (sidereal)	2.07 yr (756 days)
Mean anomaly	254.72°
Mean motion	0° 28m 33.96s / day
Inclination	4.7642°
Longitude of ascending node	110.98°
Argument of perihelion	268.77°
Earth MOID	0.0016 AU (0.6 LD)
Physical characteristics
Mean diameter	370–830 m[3]
Absolute magnitude (H)	19.3[1]

Orbit and classification

The asteroid orbits the Sun at a distance of 0.6–2.6 AU once every 2 years and 1 month (756 days). Its orbit has an eccentricity of 0.61 and an inclination of 5° with respect to the ecliptic. It has a notably low Earth minimum orbit intersection distance of 0.0016 AU (240,000 km), which is less than one lunar distance, and also approaches Mars and Venus to within 15 million kilometers.[1]

1999 MM's orbit is very similar to that of 69230 Hermes, which in 1937 made what was for decades the closest observed approach to Earth by an asteroid. Its nearest pass to Earth within at least a century of present was the 930,000 kilometers one in 1875. In 2090 it passes Venus at 788,000 kilometers.

Physical characteristics

Based on its absolute magnitude of 19.3,[1] its mean-diameter is between 370 and 830 meters, assuming an albedo in the range of 0.05 to 0.25.[3]

Numbering and naming

This minor planet was numbered by the Minor Planet Center on 19 October 2005.[4] As of 2018, it has not been named.[2]

References

External links

• MPEC from 1999 discovery
• MPEC from 2001
• Discovery Circumstances: Numbered Minor Planets (100001)-(105000) – Minor Planet Center
• List of the Potentially Hazardous Asteroids (PHAs), Minor Planet Center
• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• (101869) 1999 MM at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
• (101869) 1999 MM at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical Properties · Summary
• (101869) 1999 MM at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

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