2018 CN2
{{Short description|Very small asteroid}}
{{Use dmy dates|date=February 2018}}
{{DISPLAYTITLE:{{mp|2018 CN|2}}}}
{{Infobox planet
| minorplanet = yes
| name = {{mp|2018 CN|2}}
| background = #FFC2E0
| image = 2018_CN2 orbit.png
| image_scale =
| caption = The orbit before and after flyby, with positions on 1 February 2018, before flyby
| discoverer = Mount Lemmon Srvy.
| discovery_site = Mount Lemon Obs.
| discovered = 8 February 2018
{{small|(first observed only)}}
| mpc_name = {{mp|2018 CN|2}}
| alt_names =
| pronounced =
| named_after =
| mp_category = NEO{{·}}Apollo
{{nowrap|Earth- and Mars crosser}}
| epoch = 23 March 2018 (JD 2458200.5)
| uncertainty = 7
| observation_arc = 1 day
| aphelion = 1.7740 AU
| perihelion = 0.6335 AU
| semimajor = 1.2037 AU
| eccentricity = 0.4738
| period = 1.32 yr (482 days)
| mean_anomaly = 348.58°
| mean_motion = {{Deg2DMS|0.7463|sup=ms}} / day
| inclination = 25.741°
| asc_node = 320.21°
| arg_peri = 276.55°
| moid = {{val|7.7|e=-5|u=AU}} (0.03 LD)
| mean_diameter = 5–16 m
{{val|9|u=m}} {{small|(est. at 0.20)}}
{{val|17|u=m}} {{small|(est. at 0.057)}}
| albedo =
| spectral_type =
}}
{{mp|2018 CN|2}} is a very small asteroid, classified as a near-Earth object of the Apollo group, approximately 5 to 16 meters in diameter. It was first observed by astronomers of the Mount Lemmon Survey at Mount Lemmon Observatory, Arizona, on 8 February 2018, one day prior its close encounter with Earth at 0.18 lunar distances.
Orbit and classification
{{mp|2018 CN|2}} is a member of the Apollo asteroids, which cross the orbit of Earth. Apollo's are the largest group of near-Earth objects with nearly 10 thousand known objects.
Based on a high orbital uncertainty, this asteroid orbits the Sun at a distance of 0.63–1.77 AU once every 16 months (482 days; semi-major axis of 1.20 AU). Its orbit has an eccentricity of 0.47 and an inclination of 26° with respect to the ecliptic. With an aphelion of 1.77 AU, it is also a Mars-crosser, as it crosses the orbit of the Red Planet at 1.666 AU. The body's observation arc begins at Mount Lemmon with its first observation on 8 February 2018.
= Close encounters =
The object has an exceptionally low minimum orbital intersection distance with Earth of {{convert |0.000077 |AU |km |abbr=on |lk=off |sigfig=3 |order=flip}}, or 0.03 lunar distances (LD).
== 2018 flyby ==
On 9 February 2018, {{mp|2018 CN|2}} passed at a nominal distance of only {{convert |0.000466964 |AU |km mi |abbr=on |lk=off |sigfig=3 |order=flip}} from Earth at 7:25 UTC. This corresponds to 0.18 LD. Based on the body's high orbital uncertainty, all subsequent close encounters in 2022, 2023, 2026, 2027 and 2031, are projected to occur at a distance of more than 15 million kilometers (0.1 AU; 39 LD).
{{multiple image
|direction = horizontal
|align = left
|width1 = 330
|width2 = 205
|image1 = 2018_CN2 skyview.png
|image2 = 2018_CN2 flyby.png
|footer = 2018 flyby: Its path across the sky on 9 February was north to south (15 minute positions shown) (left). Seen from space, it passes just outside geosynchronous orbit (right).
}}
{{clear|left}}
Physical characteristics
The Minor Planet Center estimates a diameter of 5–16 meters. Based on a generic magnitude-to-diameter conversion, {{mp|2018 CN|2}} measures between 9 and 17 meters in diameter, for an absolute magnitude of 27.653, and an assumed albedo between 0.057 and 0.20, which represent typical values for carbonaceous and stony asteroids, respectively.
As of 2018, no rotational lightcurve of {{mp|2018 CN|2}} has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.
Numbering and naming
This minor planet has neither been numbered nor named.
See also
References
{{reflist|refs=
|type = 2018-02-09 last obs.
|title = JPL Small-Body Database Browser: (2018 CN2)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3799286;cad=1
|publisher = Jet Propulsion Laboratory
|accessdate = 15 February 2018}}
|title = 2018 CN2
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=2018+CN2
|accessdate = 15 February 2018}}
|title = Asteroid Size Estimator
|publisher = CNEOS NASA/JPL
|url = https://cneos.jpl.nasa.gov/tools/ast_size_est.html
|accessdate = 15 February 2018}}
|title = 2018 CN2
|author = Minor Planet Center
|publisher = Twitter
|url = https://twitter.com/MinorPlanetCtr/status/962463278684307462
|accessdate = 10 February 2018}}
}}
External links
{{Commons category}}
- [https://minorplanetcenter.net/mpec/K18/K18C76.html MPEC MPEC 2018-C76 : 2018 CN2], Minor Planet Electronic Circular, 10 February 2018
- [https://web.archive.org/web/20180216025436/http://iawn.net/2018/02/10/asteroid-2018-cn2-close-approach/ Asteroid 2018 CN2 close approach], International Asteroid Warning Network (IWAN)
- [https://watchers.news/2018/02/11/asteroid-2018-cn2/ Asteroid 2018 CN2 flew past Earth at 0.18 LD, discovered one day before closest approach], The Watchers, 11 February 2018
- {{NeoDys|2018CN2}}
- {{JPL small body|id=3799286}}
{{2018 in space}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:2018 CN2}}
Category:Minor planet object articles (unnumbered)