(696513) 2016 NL56 (provisional designation 2016 NL56) is a near-Earth object (NEO) and a potentially hazardous object (PHA), meaning that it has an orbit that can make close approaches to the Earth and large enough to cause significant regional damage in the event of impact. It is an Apollo asteroid, meaning that it is an Earth-crossing asteroid that has an orbit larger than the orbit of the Earth. It was first observed on 12 July 2016, when the asteroid was more than 1 AU from Earth[1] and had a solar elongation of 163 degrees.[6]
| Discovery[1][2] | |
|---|---|
| Discovered by | Pan-STARRS 1 |
| Discovery site | Haleakala Obs. |
| Discovery date | 12 July 2016 |
| Designations | |
| 2016 NL56 | |
| 2021 NL2[3] | |
| NEO · Apollo · PHA[1][2][4] | |
| Orbital characteristics[4] | |
| Epoch 1 July 2021 (JD 2459396.5) | |
| Uncertainty parameter 1 | |
| Observation arc | 19.93 yr (7,280 d) |
| Aphelion | 2.1730 AU |
| Perihelion | 0.6402 AU |
| 1.4066 AU | |
| Eccentricity | 0.5448 |
| 1.67 yr (609 d) | |
| 279.49° | |
| 0° 35m 26.88s / day | |
| Inclination | 4.6011° |
| 340.93° | |
| 87.408° | |
| Earth MOID | 0.0035 AU (1.36 LD) |
| Venus MOID | 0.01456 AU (2,180,000 km)[1] |
| Mars MOID | 0.02041 AU (3,050,000 km) |
| Physical characteristics | |
| 230 m (est. at 0.14)[2][5] | |
| 20.89[1] 20.913[4] | |
This asteroid had been a lost asteroid until its rediscovery as, and identification with 2021 NL2, in July 2021.[3][7] With additional observations recovered dating back as far as August 2001, the object's previously short observation arc of 2.8 days has been extended to almost 20 years, and its roughly calculated orbit has become secure with an uncertainty parameter of 1.[1][4] It orbits the Sun at a distance of 0.6–2.2 AU once every 20 months (609 days; semi-major axis of 1.41 AU). Its orbit has a high eccentricity of 0.54 and an inclination of 5° with respect to the ecliptic.[4] Based on a generic magnitude-to-diameter conversion, 2016 NL56 measures approximately 230 meters (750 ft) in diameter, for an absolute magnitude of 20.9 and an albedo of 0.14.[2][5]
This asteroid has been in both the Risk List[2] of the European Space Agency (ESA) - Space Situational Awareness (SSA) and in the Sentry List[8] of the Jet Propulsion Laboratory (JPL) - Center for Near Earth Object Studies (CNEOS). On 21 July 2021, this object was removed from the Sentry List,[9] where it was previously listed with the highest Palermo Technical Impact Hazard Scale value due to a possible close encounter with Earth on 5 September 2024.[10]
On 28 February 2122, 2016 NL56 will make its closest encounter with Earth at a nominal distance of 1,710,000 kilometers (0.01144 AU). Two hours later, it will pass the Moon at a nominal distance of 1,320,000 kilometers (0.00885 AU).[11] On 11 May 2148, the asteroid will also approach Mars at a nominal distance of 3,460,000 kilometers (0.02316 AU).[11]
See also
editReferences
edit- ^ a b c d e f "2016 NL56". Minor Planet Center. Retrieved 21 July 2021.
- ^ a b c d e "ESA space situational awareness 2016NL56". European Space Agency. Retrieved 4 August 2020.
- ^ a b "2016 NL56 = 2021 NL2". Minor Planet Electronic Circular. 21 July 2021.
- ^ a b c d e "JPL Small-Body Database Browser: (2016 NL56)" (2021-07-17 last obs.). Jet Propulsion Laboratory. Retrieved 21 July 2021.
- ^ a b "Asteroid Size Estimator". CNEOS NASA/JPL. Retrieved 11 September 2020.
- ^ "JPL HORIZONS Web-Interface (2016 NL56)". Jet Propulsion Laboratory. Retrieved 4 August 2020.
- ^ "NEODyS-2 Risk List". SpaceDys. Retrieved 4 August 2020.
- ^ "Sentry: Earth Impact Monitoring – Impact Risk Data". Jet Propulsion Laboratory. Retrieved 4 August 2020.
- ^ "Sentry: Earth Impact Monitoring – Removed Objects". CNEOS – Center for Near Earth Object Studies. Retrieved 21 July 2021.
- ^ "Sentry: Earth Impact Monitoring - Object Details 2016 NL56". Jet Propulsion Laboratory. Retrieved 4 August 2020.
- ^ a b "JPL Small-Body Database Browser: (2016 NL56)" (2021-07-17 last obs.). Jet Propulsion Laboratory. Retrieved 21 July 2021.
External links
edit- (696513) 2016 NL56 at NeoDyS-2, Near Earth Objects—Dynamic Site
- (696513) 2016 NL56 at ESA–space situational awareness
- (696513) 2016 NL56 at the JPL Small-Body Database