Asteroid 2018 CN2 flew past Earth at 0.18 LD, discovered one day before closest approach
Featured image: Featured image: The green line indicates the object's apparent motion relative to the Earth, and the bright green marks are the object's location at approximately one-hour intervals. The Moon's orbit is grey. The blue arrow points in the direction of Earth's motion and the yellow arrow points toward the Sun. Credit: Minor Planet Center.
A newly discovered asteroid designated 2018 CN2 flew past Earth at a distance of 0.18 LD / 0.00047 AU (~ 70 310 km / 43 689 miles) on February 9, 2018, one day after it was discovered. This is the 12th of 13 known asteroids to flyby Earth within 1 lunar distance since the start of the year and the second such asteroid on February 9. It is also the second closest known asteroid to fly by Earth since the start of the year, sharing this place with 2018 CB that flew past us 15 hours after CN2.
Asteroid 2018 CN2 belongs to the Apollo group of asteroids. It was first observed at Mt. Survey on February 8, just one day before its closest approach.
This asteroid has an estimated diameter between 7.8 and 18 m (25.6 – 59 feet) and it flew past us at a speed (relative to the Earth) of 20.16 km/s at 07:26 UTC.
[ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Close-Approach Data ]
This was the first known asteroid to flyby us within 1 lunar distance on February 9. The second (2018 CB) zipped past us at 22:29 UTC at a speed of 7.27 km/s (relative to the Earth).
[ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Close-Approach Data ]
The list of all known less than 1 lunar distance asteroid flybys since the start of the year (valid 16:16 UTC, February 11):

Data provided by CNEOS. Click here for a larger image.
Orbit diagram animations can be found here.
Reference:
Asteroid 2018 CN2 at Minor Planet Center; at CNEOS
Teo Blašković founded The Watchers in 2011 and edited it until 2026, covering seismic and volcanic activity, extreme weather, space weather and near-Earth objects. Articles on this page are his archive.
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