(85770) 1998 UP1

(85770) 1998 UP₁ (provisional designation 1998 UP₁) is a near Earth, Aten asteroid orbiting at nearly a 1:1 resonance with Earth.

(85770) 1998 UP₁

Discovery[1][2]
Discovered by	LINEAR
Discovery site	Lincoln Lab's ETS
Discovery date	18 October 1998
Designations
Alternative designations	1998 UP1
Minor planet category	NEO · Aten
Orbital characteristics[2]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 0
Observation arc	8787 days (24.06 yr)
Aphelion	1.3427 AU (200.87 Gm)
Perihelion	0.65377 AU (97.803 Gm)
Semi-major axis	0.99826 AU (149.338 Gm)
Eccentricity	0.34509
Orbital period (sidereal)	1.00 yr (364.30 d)
Mean anomaly	193.86°
Mean motion	0° 59m 17.484s / day
Inclination	33.180°
Longitude of ascending node	18.357°
Argument of perihelion	234.27°
Earth MOID	0.0833366 AU (12.46698 Gm)
Physical characteristics
Mean diameter	210–470 meters[3]
Absolute magnitude (H)	20.5[2]

Orbit

With an orbital period of 364.3 days, 1998 UP₁ is in a near 1:1 orbital resonance with Earth. Although their periods are almost identical, their orbits are very different; 1998 UP₁ has a highly eccentric orbit and moves between 0.65–1.35 AU from the Sun, it is also very highly inclined at 33°.^[2] The preliminary period of 1998 UP₁ was originally thought to be slightly longer than 1 year^[1] producing an error in the predicted position of about 35 degrees; it was selected as a priority for recovery and recovered by the Camarillo Observatory on 12 October 1999.^[4]

1998 UP₁ also makes close approaches to Venus and will pass at a nominal distance of 0.02563 AU (3,830,000 km; 2,380,000 mi) from Venus at 19:13 hours on 24 January 2115.^[5]

Animation of (85770) 1998 UP1 orbit from 1600 to 2500

Relative to Sun and Earth

Around Earth

Around Sun

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