2023 GQ2 is an asteroid roughly 400 meters in diameter, classified as a near-Earth object and potentially hazardous object of the Apollo group. It was first discovered on 12 April 2023, when it was 1.3 AU (190 million km) from Earth, with the Bok Telescope at Kitt Peak National Observatory.[1] On 19 April 2023, with an observation arc of 6.7 days, it was rated 1 on the Torino scale for a virtual impactor on 16 November 2028 at 00:58 UTC.[4] When it had a Palermo scale rating of –0.70,[4] the odds of impact were about 5 times less than the background hazard level and this gave the asteroid one of the highest Palermo scale ratings ever issued. On 20 April 2023 precovery images from May 2019 were announced extending the observation arc to 3.9 years,[1] and the 2028 virtual impactor was removed from the Sentry Risk Table.[2] It is now known the nominal approach will safely occur about 13 hours after the impact scenario on 16 November 2028 13:36 ± 40 minutes.[3]

2023 GQ2
Discovery[1]
Discovery siteBok Telescope @ Kitt Peak National Observatory
Discovery date12 April 2023
Designations
2023 GQ2
Orbital characteristics[3]
Epoch 25 February 2023 (JD 2460000.5)
Uncertainty parameter 3
Observation arc3.93 years
Earliest precovery date13 May 2019
Aphelion2.305 AU
Perihelion0.9837 AU
1.6444 AU
Eccentricity0.4017
2.11 yr
(770.17 days)
106.38°
Inclination36.84°
53.83°
2022-Jul-12
349.34°
Earth MOID0.0012 AU (180 thousand km; 0.47 LD)
Physical characteristics
Dimensions
  • 290–650 meters
  • ≈400 m (1,300 ft)[2]
19.8±0.3 mag[3]

The asteroid will come to aphelion (farthest distance from the Sun) around 1 August 2023.[5]

2028

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With a short 6.7 day observation arc, virtual clones of the asteroid that fit the uncertainty region in the known trajectory showed a 1-in-24,000 chance that the asteroid could impact Earth on 16 November 2028 00:58 UT.[4] With precovery images and a 3.9 year observation arc, the nominal approach (line of variation) has the asteroid 0.012 AU (1.8 million km) ± 94 thousand km from Earth at the time of the potential impact on 16 November 2028.[6] The nominal closest approach will occur about 13 hours after the impact scenario on 16 November 2028 13:36 ± 40 minutes.[3]

2023 GQ2 nominal approach for 16 November 2028 00:58 virtual impactor
Solution Observation
arc

(in days)
JPL Horizons
nominal geocentric
distance (AU)
uncertainty
region
(3-sigma)
Impact
probability
Torino
scale
Palermo
scale

(max)
JPL #1 (2023-Apr-17) 5 (26 obs) 0.0085 AU (1.27 million km) ± 90 million km 1:560000[7] 0 –2.08
JPL #3 (2023-Apr-19) 7 (29 obs) 0.0053 AU (0.79 million km) ± 16 million km 1:24000[4] 1 –0.70
JPL #4 (2023-Apr-20) 1437 (35 obs) 0.0121 AU (1.81 million km) ± 0.094 million km none[2] N/A N/A

2023 GQ2 Earth approach on 16 November 2028
(about 13 hours after the impact scenario)
Date & time Nominal distance uncertainty
region
(3-sigma)
2028-Nov-16 13:36 ± 40 minutes 1522786 km[3] ± 80 thousand km[8]

References

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  1. ^ a b c "2023 GQ2 Orbit". Minor Planet Center. Retrieved 20 April 2023.
  2. ^ a b c d "Sentry Risk Table: 2023 GQ2". NASA JPL CNEOS. Archived from the original on 17 April 2023.
  3. ^ a b c d e "JPL Small-Body Database Browser: (2023 GQ2)" (2023-04-19 last obs.). Jet Propulsion Laboratory. Archived from the original on 19 April 2023. Retrieved 20 April 2023.
  4. ^ a b c d "Archive of Sentry Risk Table: 2023 GQ2 (6.7 day arc)". NASA JPL CNEOS.
  5. ^ "Aphelion around 1 August 2023" (Aphelion occurs when rdot flips from positive to negative). JPL Horizons. Retrieved 20 April 2023.
  6. ^ "JPL Horizons: 2023 GQ2 geocentric distance and uncertainty on 16 November 2028 VI". JPL Horizons. Retrieved 20 April 2023.
  7. ^ "Archive of Sentry Risk Table: 2023 GQ2 (4.9 day arc)". NASA JPL CNEOS.
  8. ^ "JPL Horizons: 2023 GQ2 geocentric distance and uncertainty on 16 Nov 2028 close approach". JPL Horizons. Retrieved 20 April 2023.
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