2000 EM26

2000 EM₂₆

Aten asteroids (green), Sun (center), Mercury (grey), Venus (black), Earth (blue), Mars (red)
Discovery
Discovery date	5 March 2000
Designations
Alternative names	none
Minor planet category	Aten asteroid (NEO, PHO)
Orbital characteristics
Epoch 13 January 2016 (JD 2457400.5) (Uncertainty=7)
Uncertainty parameter 7
Observation arc	9 days (last seen 2000)
Aphelion	1.1995 AU (179.44 Gm)
Perihelion	0.43370 AU (64.881 Gm)
Semi-major axis	0.81659 AU (122.160 Gm)
Eccentricity	0.46890
Orbital period	0.74 yr (269.5 d)
Average orbital speed	12.37 km/s (27,700 mph)
Mean anomaly	300.355°
Inclination	3.9107°
Longitude of ascending node	344.992°
Argument of perihelion	24.279°
Earth MOID	0.0189175 AU (2.83002 Gm)
Jupiter MOID	4.25722 AU (636.871 Gm)
Physical characteristics
Dimensions	120–270 meters (390–890 feet)
Absolute magnitude (H)	21.7

2000 EM₂₆ is a near-Earth and potentially hazardous asteroid. It was discovered on 5 March 2000 and observed through 14 March 2000 by which time it had dimmed to apparent magnitude 20 and was 40 degrees from the moon. By 17 March 2000 it was only 4 degrees from a 90% waxing gibbous moon. It has never been listed on the Sentry Risk Table because none of the potential orbital solutions create a risk of impact in the next ~100 years. The asteroid is up to 270 meters (890 feet) in diameter and safely passed by Earth on 17–18 February 2014. Due to the poorly determined orbit, the asteroid may have been significantly further from Earth and dozens of degrees from where the telescope was pointed during the 2014 approach.

The 2014 approach was broadcast live (YouTube archive) on the internet at 09:00pm EST (02:00 UTC), 18 February 2014, by the Slooh community observatory. Slooh's observatory on Mount Teide in Spain's Canary Islands was iced over at the time, so images from the Slooh observatory in Dubai were used to attempt detection of the asteroid. At the time of the broadcast, no obvious image of the asteroid could be seen. Some viewers complained by Twitter that it was boring when the object was never shown in the images, while others said that "boring" was a good outcome for a pass-by.

2000 EM₂₆ is an Aten-family asteroid, and as such is often near the glare of the Sun as the asteroid seldom travels outside Earth's orbit when the Earth is nearby. The orbit is poorly determined since the asteroid has an observation arc of only 9 days creating an orbital uncertainty of 7. Since the asteroid has not been observed since 14 March 2000, the uncertainty region has kept increasing. During the 2014 approach, 17 February 2014 was the first day that the nominal orbit had a solar elongation more than 90 degrees from the Sun making it easier to recover under a dark sky. Using the nominal orbit, the asteroid was expected to have an apparent magnitude of about 16 and pass 0.02 AU (3,000,000 km; 1,900,000 mi) from Earth. Closest approach (perigee-geocentrical) was around 00:15 UTC on 18 February plus or minus about 13 hours. Even with an observation arc of 9 days, it was known that the minimum possible close approach distance to Earth on 18 February 2014 was 0.018 AU (2,700,000 km; 1,700,000 mi) with a small chance that the asteroid would pass as far as 0.13 AU (19,000,000 km; 12,000,000 mi) from Earth. Due to the uncertainty region of the asteroid, the asteroid could have been 75 degrees from the nominal position in the sky on 18 February 2014.

With an absolute magnitude (H) of 21.7, the asteroid is estimated as around 120–270 m (390–890 ft) in diameter, depending on the albedo (the amount of light it reflects).

File:Asteroid2000EM26-NearEarthEncounter-20140217.png

The nominal, but poorly determined orbit of near-Earth Asteroid 2000 EM₂₆ (17 February 2014).

See also

• List of asteroid close approaches to Earth
• 2009 RR

External links

• 2000 EM26 at Solar System Dynamics/NASA (SSD)
• 2000 EM26 at the JPL Small-Body Database

• Discovery · Orbit diagram · Orbital elements · Physical parameters