 Photograph of2023 CX1 as it entered Earth's atmosphere over northern France on 13 February 2023 | |
| Discovery[1][2] | |
|---|---|
| Discovered by | Krisztián Sárneczky |
| Discovery site | Piszkéstető Stn. |
| Discovery date | 12 February 2023 |
| Designations | |
| 2023 CX1 | |
| Sar2667 | |
| NEO · Apollo | |
| Orbital characteristics[3] | |
| Epoch 1 January 2023 (JD 2459945.5) | |
| Uncertainty parameter 5[4] | |
| Observation arc | 6.57 hours (0.27 d)[1] |
| Aphelion | 2.337AU |
| Perihelion | 0.921 AU |
| 1.629 AU | |
| Eccentricity | 0.4346 |
| 2.08 yr (760 days) | |
| 325.105° | |
| 0° 28m 25.982s / day | |
| Inclination | 3.419° |
| 323.870° | |
| 13 February 2021[5] | |
| 218.790° | |
| Earth MOID | 0.000111 AU (16,600 km; 0.043 LD) |
| Physical characteristics | |
| ≈1 m[6][7] | |
| Mass | ≈1000 kg[8] |
| ≈ 13 (peak)[1] | |
| 32.645±0.512[4] 32.76[1] | |
2023 CX1, initially known under temporary designationSar2667, was a metre-sizedasteroid that entered Earth's atmosphere on 13 February 2023 02:59UTC and disintegrated as ameteor over the coast ofNormandy, France along theEnglish Channel.[6] It was discovered less than seven hours beforeimpact, by Hungarian astronomerKrisztián Sárneczky atKonkoly Observatory'sPiszkéstető Station in theMátra Mountains,Hungary.[2][9]2023 CX1 is theseventh asteroid discovered before impacting Earth and successfullypredicted, and the third of those for whichmeteorites have been recovered. Before it impacted,2023 CX1 was anear-Earth asteroid on an Earth-crossingApollo-type orbit.[1]
During a routine search fornear-Earth objects with his 60-centimetre (24 in)Schmidt telescope,[10]Krisztián Sárneczky first imaged2023 CX1 on 12 February 2023 at 20:18:07 UTC, when it was already less than 233,000 km (145,000 mi) from Earth and inside the orbit of the Moon at 0.61lunar distances.[2][11] At discovery, the asteroid had anapparent magnitude of 19.4 and moved quickly in thenorthern hemisphere sky, at anangular rate of 14arcseconds per minute and aradial velocity of 9 km/s (32,400 km/h; 20,100 mph) towards Earth.[11] Sárneczky immediately recognized it was a near-Earth object, but only realized it was on course forimpact with Earth when he reobserved it half an hour later.[9] Sárneczky gave the object the temporary designationSar2667 and reported the discovery to theMinor 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.[12] Astronomers atVišnjan Observatory in Tičan,Croatia observed the asteroid starting at 21:03 UTC and confirmed that it was headed for impact with Earth.[2][13]
TheEuropean Space Agency took notice of the asteroid's impending impact and alerted the public through social media.[10] Astronomers around the world continuously observed the asteroid to refine its trajectory as it approached Earth and its impact location.[12][11] The asteroid reached a peak brightness of magnitude 13 (about the brightness ofPluto) right before itentered Earth's shadow at around 02:50 UTC. It then faded dramatically and became invisible until it entered the atmosphere.[1][12] The asteroid was last observed on 13 February 2023 02:52:07 UTC by Jost Jahn at theSATINO Remote Observatory inHaute Provence, France, just two minutes after it entered Earth's shadow and seven minutes before it impacted.[1][11] At the time of that 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[a]).[14]
On 13 February 2023 04:13 UTC (one hour after the impact), MPC gave the asteroid its officialminor planetprovisional designation2023 CX1. At least 20 observatories observed2023 CX1 and submittedastrometry to the MPC before impact, with over 300 astrometric positions recorded in total.[2][1]
At 02:59:21 UTC (local time 03:59:21CET),2023 CX1 entered the atmosphere at a velocity of 14.5 km/s (52,200 km/h; 32,436 mph) with an inclination 40–50° relative to the vertical.[13][15] As the meteoroid travelled eastward over theEnglish Channel to the coast ofNormandy, France, it experienced significantatmospheric drag and began burning up as a brightmeteor at an altitude of 89 km (55 mi).[13][8] It was seen by witnesses from France, Great Britain, Belgium, Netherlands, and Germany.[10][16] The meteor began fragmenting at an altitude of 29 km (18 mi) and then completely broke apart at 28 km (17 mi), producing a bright flash due to the rapid vaporization of its fragments.[8] In the process, the meteor released a great amount ofkinetic energy. That produced ashock wave, which was heard by some witnesses and was detected by Frenchseismographs.[15] The meteor disappeared at an altitude of 20 km (12 mi), after which its resultingmeteorites continued falling indark flight.[8] Over 80 witness reports of the meteor were submitted to theInternational Meteor Organization (IMO).[16]
Upon breakup,2023 CX1 dropped meteorites over theNormandyregion and produced astrewn field spanning fromDieppe toDoudeville.[15] Guided byPeter Jenniskens, researchers andcitizen scientists of the Fireball Recovery and Interplanetary Observation Network (FRIPON) immediately began a coordinated search effort in the expectedmeteorite fall area.[17] On 15 February 2023 15:47 UTC (local time 16:47 CET), FRIPON member and art student Loïs Leblanc found the first meteorite of2023 CX1 in a field in thecommune ofSaint-Pierre-le-Viger.[17] The meteorite weighed about 95 g (3.4 oz)[18] and is described as a "dark stone."[17][19] Late in the afternoon of the next day, Peter Jenniskens found a 3 g meteorite near the small-size end of the strewn field that confirmed the predicted center line. By March 2023, over 20 additional meteorites were recovered, with masses ranging 2 to 350 g (0.1 to 12.3 oz).[18] The IMO estimates that2023 CX1 could have dropped only one large meteorite up to ~2 kg (4.4 lb) in mass, plus an uncertain number of smaller meteorites up to several tens of grams each.[6][8] The largest meteorite is expected to have landed near the commune ofVénestanville.[8]
2023 CX1 is the seventh asteroid discovered before being successfullypredicted to impact Earth, and also the third whose meteorites were collected after its predicted impact.[6][17] It is Sárneczky's second discovery of an impacting asteroid, after2022 EB5 which he discovered a year prior in March 2022.[10]
Prior to impact,2023 CX1 was on anApollo-type orbit that crossed the orbits of Earth and Mars.[3] It orbited the Sun at an average distance of 1.63astronomical units (244×10^6 km; 152×10^6 mi), varying from 0.92 AU atperihelion to 2.34 AU ataphelion due to itseccentric orbit.[3] The orbit had a lowinclination of 3.4° with respect to theecliptic and anorbital period of 2.08 years. The asteroid last passed perihelion on 13 February 2021 and impacted Earth before it was set to make its next perihelion on 15 March 2023.[5][3]
The last time2023 CX1 made a close approach to Earth was around 7 (± 1) June 2000, when it passed around 150–161 LD (58–62 million km; 36–38 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 probably never approached within 10 LD (3.8 million km; 2.4 million mi) from these planets.[4]
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