2014 ES57

2014 ES₅₇ is a Greek camp Jupiter trojan^[1] roughly 5.6 kilometers (3 miles) in diameter^[a] that was briefly listed on the Sentry Risk Table in April 2021 when JPL transitioned to DE441. Once listed on the Sentry Risk Table additional archived observations were quickly located that confirmed 2014 ES₅₇ is a harmless Jupiter trojan that does not get closer to Earth than 3.8 AU (570 million km).^[1] Once the new astrometry was verified and published it was removed from the Sentry Risk Table on 4 May 2021.

2014 ES₅₇

Discovery[1]
Discovered by	DES-DECam
Discovery site	Cerro Tololo Obs.
Discovery date	2 March 2014
Designations
MPC designation	2014 ES57
Minor planet category	Jupiter trojan[1][2] Greek[3]
Orbital characteristics[2]
Epoch 1 July 2021 (JD 2459396.5)
Uncertainty parameter 0
Observation arc	12.05 yr (4,402 d)
Earliest precovery date	22 September 2009
Aphelion	5.73 AU
Perihelion	4.80 AU
Semi-major axis	5.26 AU
Eccentricity	0.0882
Orbital period (sidereal)	12.07 yr (4,410 d)
Mean anomaly	306°
Mean motion	0° 4m 53.76s / day
Inclination	6.42°
Longitude of ascending node	229°
Argument of perihelion	203°
Earth MOID	3.81 AU
Jupiter MOID	0.191 AU
TJupiter	2.980
Physical characteristics
Mean diameter	5.6 km (est.)[a]
Absolute magnitude (H)	14.98[2] 14.99[1]

When 2014 ES₅₇ had a short observation arc of 3 days, some orbit solutions suggested it could be a near-Earth object^[4] that was discovered when it was near aphelion 7 AU from the Sun.^[5] As a result of the possible near-Earth orbit, the Sentry Risk Table listed a non-significant 1:1-billion chance of impacting Earth on 12 October 2059.^[6]

Notes

1. Given an absolute magnitude (H) of 14.98 and a trojan albedo for a carbonaceous asteroid of 0.057, yields a mean diameter of around 5.6 kilometer or 3 miles.^[b]

References

1. "2014 ES57". Minor Planet Center. Retrieved 18 October 2021.
2. "JPL Small-Body Database Browser: 2014 ES57" (2021-10-11 last obs.). Jet Propulsion Laboratory. Retrieved 18 October 2021. (Archived 6 May 2021)
3. "List of Jupiter Trojans". Minor Planet Center. 27 September 2021. Retrieved 18 October 2021.
4. JPL #5 DE441 (solution date:2021-Apr-15) listed as an Apollo NEO with perihelion of 0.7 AU (Wayback Machine archive)
5. Find_Orb showing "discovery" near aphelion of 7 AU (Wayback Machine archive)
6. "Earth Impact Risk Summary: 2014 ES57". NASA/JPL Near-Earth Object Program Office. Retrieved 27 April 2021.
7. "Asteroid Size Estimator". CNEOS NASA/JPL. Retrieved 18 October 2021.

External links

• VI (virtual impactor) date of 2059-10-12 at 0.5AU (Wayback Machine archive)
• Minor Planet Mailing List (MPML) discussion (April 2021)
• 2014 ES57 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters