Discovery [1] | |
---|---|
Discovered by | Mount Lemmon Survey |
Discovery date | 11 October 2021 |
Designations | |
2021 TP21 | |
Orbital characteristics [2] | |
Epoch 2021-Jul-01 ( JD 2459396.5) | |
Uncertainty parameter 6 | |
Observation arc | 57 days |
Aphelion | 4.2274 AU (Q) |
Perihelion | 0.81425 AU (q) |
2.5208 AU (a) | |
Eccentricity | 0.67699 (e) |
4.00 years | |
318.4 ° (M) | |
Inclination | 25.404° (i) |
8.089° (Ω) | |
116.3° (ω) | |
Earth MOID | 0.03 AU (4.5 million km) |
Jupiter MOID | 1.7 AU (250 million km) |
Physical characteristics | |
Dimensions |
|
20.2 [2] [4] | |
2021 TP21 is an Apophis-sized asteroid that was discovered on 11 October 2021 when it was 0.5 AU (75 million km) from Earth. [1] This potentially hazardous asteroid (PHA) spends most or its orbit closer to 4 AU (600 million km) from the Sun as objects orbit more slowly when near aphelion (furthest distance from the Sun). 2021 TP21 was rated with a Torino scale of 1 from 31 October 2021 to 4 November 2021 for a potential impact on 27 March 2081. [3] As the observation arc became longer the nominal distance from Earth became further on the potential impact date.
Observation arc (in days) |
JPL Horizons nominal geocentric distance ( AU) |
uncertainty region ( 3-sigma) |
Impact probability (1 in) |
Torino scale |
---|---|---|---|---|
17 | 0.17 AU (25 million km) [5] | ± 1.5 billion km [5] | 100000 | 0 |
19 | 1.4 AU (210 million km) [6] | ± 870 million km [6] | 50000 [3] | 1 [3] |
57 | 2.5 AU (370 million km) [7] | ± 18 million km [7] | 0 | 0 |