2019 UN13 is a small near-Earth asteroid roughly 1–2 meters in diameter. Even though the asteroid was in the night sky for months, it was fainter than the sky survey limit of apparent magnitude 24 until 29 October 2019 when the asteroid was two million km from Earth.[7] It was discovered on October 31, 2019, passing 6,200 km above Earth's surface.[8][9]
| Discovery [1] | |
|---|---|
| Discovered by | CSS (Teddy Pruyne) |
| Discovery site | Catalina Stn. |
| Discovery date | 31 October 2019 (first observed only) |
| Designations | |
| 2019 UN13 | |
| C0PPEV1[2] | |
| NEO · Aten [1][3] | |
| Orbital characteristics [3] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 7 | |
| Observation arc | 3.7 hours[1] (18 observations) |
| Aphelion | 1.3301 AU (2.06 AU after passage) |
| Perihelion | 0.6463 AU |
| 0.9882 AU | |
| Eccentricity | 0.3460 |
| 359 days | |
| 100.74° | |
| 1° 0m 12.24s / day | |
| Inclination | 1.4925° |
| 217.58° | |
| 291.05° | |
| Earth MOID | 0.000005 AU (700 km) |
| Physical characteristics | |
| 1–2 m[4][5][6] | |
| Mass | 2800 kg (est.)[4] |
| 32.0[1][3] | |
2020 QG and 2011 CQ1 are the only asteroids known where the nominal orbit passed closer to the surface of Earth.[6] Other asteroids that passed very close to Earth include 2004 FU162, 2018 UA, and 2019 AS5.
An impact by 2019 UN13 would be less significant than the 2018 LA impact.
2019 flyby
edit
- 5 minute markers of trajectory above the earth near closest approach
Orbit changes
editThe close approach to Earth lifted the asteroid's aphelion point (furthest distance from the Sun) from 1.33 AU (inside the orbit of Mars) to 2.06 AU (near the edge of the inner asteroid belt). The approach changed the orbit from an Aten asteroid with a semi-major axis less than 1 AU to an Apollo asteroid with a semi-major axis greater than that of the Earth (> 1 AU).
| 2019[3] | 2020 | |
|---|---|---|
| Orbit type | Aten | Apollo |
| Perihelion (closest distance to the Sun) |
0.64 AU | 0.83 AU |
| Semi-major axis (average distance from the Sun) |
0.98 AU | 1.4 AU |
| Aphelion (furthest distance from the Sun) |
1.3 AU | 2.0 AU |
| Orbital period | 358 days | 637 days |
With the new orbit, 2019 UN13 will come to perihelion 0.83 AU from the Sun on 15 December 2019. Without perturbations, the previous orbit would have come to perihelion in January 2020.
Future
editThere is a small chance the asteroid will pass 0.0001 AU (15,000 km) from Mars on 26 October 2023.[3] There is also a 1 in 3 million chance the asteroid will impact Earth on 1 November 2111.[4]
See also
edit| Asteroid | Date | Distance from surface of Earth |
Uncertainty in approach distance |
Observation arc | Reference |
|---|---|---|---|---|---|
| 2020 VT4 | 2020-11-13 17:21 | 368 km | ±11 km | 5 days (34 obs) | data |
| 2020 QG | 2020-08-16 04:09 | 2939 km | ±11 km | 2 days (35 obs) | data |
| 2021 UA1 | 2021-10-25 03:07 | 3049 km | ±10 km | 1 day (22 obs) | data |
| 2023 BU | 2023-01-27 00:29 | 3589 km | ±<1 km | 10 days (231 obs) | data |
| 2011 CQ1 | 2011-02-04 19:39 | 5474 km | ±5 km | 1 day (35 obs) | data |
| 2019 UN13 | 2019-10-31 14:45 | 6235 km | ±189 km | 1 day (16 obs) | data |
| 2008 TS26 | 2008-10-09 03:30 | 6260 km | ±970 km | 1 day (19 obs) | data |
| 2004 FU162 | 2004-03-31 15:35 | 6535 km | ±13000 km | 1 day (4 obs) | data |
References
edit- ^ a b c d "2019 UN13". Minor Planet Center. Retrieved 1 November 2019.
- ^ "Pseudo-MPEC for C0PPEV1". Archived from the original on 1 November 2019. Retrieved 1 November 2019.
- ^ a b c d e "JPL Small-Body Database Browser: (2019 UN13)" (2019-10-31 last obs.). Jet Propulsion Laboratory. Archived from the original on 3 November 2019. Retrieved 1 November 2019.
- ^ a b c "Earth Impact Risk Summary: 2019 UN13". NASA/JPL Near-Earth Object Program Office. Archived from the original on 2 November 2019. Retrieved 2 November 2019.
- ^ "esa: 2019 UN13". ESA. Archived from the original on 3 November 2019. Retrieved 3 November 2019.
- ^ a b Go to https://cneos.jpl.nasa.gov/ca/ and for Table Settings select "Nominal distance <= 1 LD", "Past only" and sort by "CA distance nominal"
- ^ "2019UN13 Ephemerides for October 2019". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 3 November 2019.
- ^ "Spooky Halloween asteroid flyby one of the closest near misses ever seen"..
- ^ Newly-discovered #asteroid C0PPEV1 Twitter message
External links
edit- MPEC 2019-V09 : 2019 UN13, Minor Planet Electronic Circular, 1 November 2019
- Catalina Sky Survey Scares-Up Tiny Earth-Grazing Halloween Asteroid, CSS, 1 November 2019
- Small asteroid paid a heavy price for almost striking Earth Thursday, EarthSky, 1 November 2019
- This small asteroid almost struck Earth on Halloween, Deseret News, 1 November 2019
- 2019 UN13 Geometry, IAWN – International Asteroid Warning Network
- 2019 UN13 at NeoDyS-2, Near Earth Objects—Dynamic Site
- 2019 UN13 at the JPL Small-Body Database