2019 UN13

Summary

2019 UN13
Discovery [1]
Discovered byCSS (Teddy Pruyne)
Discovery siteCatalina Stn.
Discovery date31 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 arc3.7 hours[1]
(18 observations)
Aphelion1.3301 AU
(2.06 AU after passage)
Perihelion0.6463 AU
0.9882 AU
Eccentricity0.3460
359 days
100.74°
1° 0m 12.24s / day
Inclination1.4925°
217.58°
291.05°
Earth MOID0.000005 AU (700 km)
Physical characteristics
Mean diameter
1–2 m[4][5][6]
Mass2800 kg (est.)[4]
32.0[1][3]

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]

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

2019UN13-hover.png

5 minute markers of trajectory above the earth near closest approach

Orbit changes

The 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).

Orbital elements for April 2019 and April 2020
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

There 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

Closest non-impacting asteroids to Earth, except Earth-grazing fireballs
Asteroid Date Distance from
surface of Earth
Uncertainty in
approach distance
Reference
2020 VT4 2020-11-13 374 km ±25 km data
2020 QG 2020-08-16 2946 km ±20 km data
2011 CQ1 2011-02-04 5481 km ±5 km data
2019 UN13 2019-10-31 6242 km ±200 km data
2008 TS26 2008-10-09 6259 km ±1000 km data
2004 FU162 2004-03-31 6542 km ±15000 km data

References

  1. ^ a b c d "2019 UN13". Minor Planet Center. Retrieved 1 November 2019.
  2. ^ "Archived copy". Archived from the original on 1 November 2019. Retrieved 1 November 2019.CS1 maint: archived copy as title (link)
  3. ^ 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.
  4. ^ 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.
  5. ^ "esa: 2019 UN13". ESA. Archived from the original on 3 November 2019. Retrieved 3 November 2019.
  6. ^ 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"
  7. ^ "2019UN13 Ephemerides for October 2019". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 3 November 2019.
  8. ^ https://www.cnet.com/news/spooky-halloween-asteroid-flyby-one-of-the-closest-near-misses-ever-seen/
  9. ^ https://twitter.com/tony873004/status/1190017524777111553

External links

  • 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
    • Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
  • 2019 UN13 at the JPL Small-Body Database
    • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters