2023 CX₁

During a routine search for near-Earth objects with his 0.6-metre (2 ft) Schmidt telescope,[9] Krisztián Sárneczky first imaged 2023 CX₁ on 12 February 2023 at 20:18:07 UTC, when it was less than 233,000 km (145,000 mi) from Earth and inside the orbit of the Moon at 0.61 lunar distances.[2][10] At discovery, the asteroid had an apparent magnitude of 19.4 and moved quickly in the northern hemisphere sky, at an angular rate of 14 arcseconds per minute and a radial velocity of 9 km/s (5.6 mi/s) towards Earth.[10] Sárneczky immediately recognized it was a near-Earth object but did not realize it was on course for impact with Earth until he reobserved it half an hour later.[8] Sárneczky gave the object the temporary designation Sar2667 and reported the discovery to the Minor Planet Center's (MPC's) Near-Earth Object Confirmation Page at 20:49 UTC, calling for further follow-up from other observatories around the world.[11] Astronomers at Višnjan Observatory in Tičan, Croatia observed the asteroid starting at 21:03 UTC and confirmed that it was headed for impact with Earth.[2][12]

The European Space Agency took notice of the asteroid's impending impact and alerted the public through social media.[9] Astronomers around the world continuously observed the asteroid to refine its trajectory and impact location as it approached Earth.[11][10] The asteroid reached a peak brightness of magnitude 13 right before it entered Earth's shadow at around 02:50 UTC, after which it faded and became invisible until impact.[1][11] The asteroid was last observed on 13 February 2023 02:52:07 UTC by the SATINO Remote Observatory in Haute Provence, France, just two minutes after the asteroid entered Earth's shadow and seven minutes before it impacted.[1][10] At the time of last observation, the asteroid had faded from magnitude 13 to 16 and moved extremely quickly at an angular rate of 1.7 degrees per minute, at a distance of approximately 11,100 km (6,900 mi) from Earth's center (4,700 km or 2,900 mi altitude[lower-alpha 1]).[13]

After the impact, the MPC announced the object with the official minor planet provisional designation 2023 CX₁ on 13 February 2023. At least 20 observatories have observed and submitted astrometry of the meteoroid to the MPC before impact, with over 300 astrometric positions recorded in total.[2][1]

2023 CX₁ entered the atmosphere at 02:59:21 UTC and traveled eastward over the coast of Normandy, France along the English Channel, falling at a 40–50° inclination relative to vertical.[7][12] As it experienced atmospheric drag during its high-speed entry, it burned up as a bright meteor that was seen by witnesses from France, Great Britain, Belgium, the Netherlands, and northern Spain.[9][14] Over 60 witness reports of the meteor were submitted to the International Meteor Organization.[14] Some fragments of the meteor may have survived atmospheric entry and may have left a strewn field of meteorites close to the Normandy shore.[11]

2023 CX₁ is the seventh asteroid discovered before being successfully predicted to impact Earth.[6] It is also Sárneczky's second discovery of an impacting asteroid, after 2022 EB5 which he discovered a year prior in March 2022.[9]

Prior to impact, 2023 CX₁ was on an Apollo-type orbit that crossed the orbits of Earth and Mars.[3] It orbited the Sun at an average distance of 1.63 astronomical units (244×10^⁶ km; 152×10^⁶ mi), varying from 0.92 AU at perihelion to 2.34 AU at aphelion due to its eccentric orbit.[3] The orbit had a low inclination of 3.4° with respect to the ecliptic and an orbital period of 2.08 years. The asteroid last passed perihelion on 28 February 2022 and impacted Earth before it was set to make its next perihelion on 15 March 2023.[5][3]

The last time 2023 CX₁ made a close approach to Earth was around 7 (± 1) June 2000, when it passed around 143–162 LD (55–62 million km; 34–39 million mi) from the planet.[4] Before that, 2023 CX₁ had made several distant close approaches with Earth and Mars during the 1900s, though it never approached within 10 LD (3.8 million km; 2.4 million mi) from these planets.[4]

• Asteroid impact prediction
• Impact event
• 2022 WJ1, a meteoroid that impacted over Southern Ontario, Canada

• 2023 CX1 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemerides · Observation prediction · Orbital info · MOID · Proper elements · Observational info · Close approaches · Physical info · Orbit animation
• 2023 CX1 at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical properties · Summary
• 2023 CX1 at the JPL Small-Body Database