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(276033) 2002 AJ129, provisional designation 2002 AJ129, is a Mercury-crossing asteroid. It has the ninth-smallest perihelion of all numbered asteroids, after asteroids such as 2000 BD19, 2004 UL, and 2008 XM. It makes close approaches to all of the inner planets and asteroid 4 Vesta. The asteroid is estimated to be between 0.5–1.2 kilometers (0.3–0.7 mi) across. In January 2018 there was much media hype about this asteroid being classified as a potentially hazardous asteroid, although there is no known threat of an impact for hundreds if not thousands of years. The media has compared the size of the asteroid to the Burj Khalifa in Dubai.
(529366) 2009 WM1, provisional designation 2009 WM1, is a sub-kilometer asteroid and near-Earth object of the Apollo group, approximately 280 meters (920 feet) in diameter. After its discovery by the Catalina Sky Survey at the Catalina Station in Arizona, United States, this potentially hazardous asteroid was briefly listed at a Torino Scale of 1 and a cumulative Palermo Scale of −0.87. It was removed from the Sentry Risk Table on 26 June 2013.
(367789) 2011 AG5, provisional designation 2011 AG5, is a sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It has a diameter of about 140 meters (460 ft). It was removed from the Sentry Risk Table on 21 December 2012 and as such it now has a rating of 0 on the Torino Scale. It was recovered in December 2022 extending the observation arc from 4.8 years to 14 years. As of 2023, the distance between the orbits of Earth and 2011 AG5 is 0.0004 AU (60,000 km; 0.16 LD)
(612358) 2002 JE9 (also written 2002 JE9) is an Apollo near-Earth asteroid and potentially hazardous object. It has a well determined orbit with an observation arc of 10 years and an Uncertainty Parameter of 1. It was removed from the Sentry Risk Table on 10 May 2002. 2002 JE9 was discovered on 6 May 2002 by the Lincoln Near-Earth Asteroid Research (LINEAR) project using a 1.0-metre (39 in) Reflecting telescope; at the time of discovery, the asteroid possessed an apparent magnitude of 19.1.
2010 AU118 (also written 2010 AU118) is a potential Amor near-Earth asteroid with an observation arc of only 1.4 days and thus a poorly determined orbit. It was announced on 27 May 2010 based on images taken by the Wide-field Infrared Survey Explorer (WISE) on 13–15 January 2010. It was removed from the Sentry Risk Table on 14 June 2014 as a result of an update to the Sentry software. Another software update restored it to the Sentry Risk Table in 2017. It was again removed from the sentry list on 3 October 2018.
2012 KP24 (also written 2012 KP24) is a Chelyabinsk-sized near-Earth asteroid with an observation arc of only 5 days and has a modestly determined orbit for an object of its size. Around 31 May 2023 ±3 days it will pass between 0.19–24 lunar distances (73,000–9,200,000 km) from Earth. Nominally the asteroid is expected to pass 0.026 AU (3,900,000 km; 10 LD) from Earth and brighten to around apparent magnitude 21.6.
2008 CK70 (also written 2008 CK70) is an Apollo near-Earth asteroid. In 2013 it had the 7th highest impact threat on the Palermo Technical Impact Hazard Scale. It was discovered on 9 February 2008 by Lincoln Near-Earth Asteroid Research (LINEAR) at an apparent magnitude of 19 using a 1.0-meter (39 in) reflecting telescope. It has an estimated diameter of 31 meters (102 ft) and is not large enough to qualify as a potentially hazardous object. Ten precovery images from January 2008 have been located. It was removed from the Sentry Risk Table on 21 December 2013. It may be possible to recover the asteroid in late September 2017, but it will have an apparent magnitude of about 22.
2011 XC2 (also written 2011 XC2) is a near-Earth asteroid roughly 60–140 meters (200–460 ft) in diameter that passed less than 1 lunar distance from Earth on 3 December 2011.
2014 XL7 is a near-Earth object and Apollo asteroid, approximately 230 meters (750 feet) in diameter. It was the most dangerous potentially hazardous asteroid on Sentry Risk Table upon its discovery by the Mount Lemmon Survey in December 2014. At the time, the asteroid had a cumulative 1 in 83000 chance of impacting Earth on 4–5 June between the years 2048 and 2084. After the object's observation arc had been extended to 35 days, it was removed from the Sentry Risk Table on 15 January 2015. Since then the asteroid's orbit has been secured. Although it has an Earth minimum orbit intersection distance of less than one lunar distance, there are no projected close encounters with Earth in the foreseeable future, with its closest passage to occur in May 2046, still millions of kilometers away.
2015 AZ43 (also written 2015 AZ43) is an Apollo near-Earth asteroid roughly 70 meters in diameter. On 10 February 2015 with a 29.5-day observation arc, it showed a 1 in 5,880 chance of impacting Earth on 27 February 2107. However, the NEODyS nominal best-fit orbit shows that 2015 AZ43 will be 2.8 AU (420,000,000 km; 260,000,000 mi) from Earth on 27 February 2107. A (non-impacting) Earth close approach in 2056 makes future trajectories diverge. It was removed from the JPL Sentry Risk Table on 23 February 2015 using JPL solution 26 with an observation arc of 40 days that included radar data.
2018 LF16 is a small Mars crossing asteroid roughly 213 m (699 ft) in diameter. It was first observed by astronomers with the Pan-STARRS survey at Haleakala Observatory on 14 June 2018. It was removed from the Sentry Risk Table on 29 July 2021. With an observation arc of 15 years the orbit is very well known and it does not make any notable approaches to Earth.
2018 XB4 (also written 2018 XB4) is an Apollo near-Earth asteroid roughly 53 meters (170 feet) in diameter. It was discovered on 13 December 2018 when the asteroid was about 0.125 AU (18,700,000 km; 11,600,000 mi) from Earth and had a solar elongation of 146°. It passed closest approach to Earth on 1 January 2019. Of the asteroids discovered in 2018, it had the highest Palermo scale rating at –3.6. In mid-2019 it was recovered which extended the observation arc to 177 days and was removed from the Sentry Risk Table on 12 June 2019. It is now known that on 22 June 2092 the asteroid will pass about 0.033±0.015 AU from Earth.
2006 QV89 (also written 2006 QV89) is an Apollo near-Earth asteroid roughly 30 meters (100 feet) in diameter. It was discovered on 29 August 2006 when the asteroid was about 0.03 AU (4,500,000 km; 2,800,000 mi) from Earth and had a solar elongation of 150 degrees.
2014 MV67 (also written 2014 MV67) is a Mars-crosser and former lost asteroid with an observation arc of less than 1 day. Before its recovery, it had an assumed orbital eccentricity and a very poorly constrained orbit. Depending on the orbit, it could have been a potentially hazardous asteroid, roughly 540 meters (1,770 feet) in diameter, or it could turn out to be a Mars-crosser or even a main-belt asteroid as were the cases with 2004 BX159 and 2010 GZ60. It was recovered by Pan-STARRS in September 2021 and is now known to be a Mars-crossing asteroid.
2011 ES4 (also written 2011 ES4) is an Apollo near-Earth asteroid roughly 22–49 meters (72–160 feet) in diameter. It was first observed on 2 March 2011 when the asteroid was about 0.054 AU (8,100,000 km; 5,000,000 mi) from Earth and had a solar elongation of 159 degrees. It passed closest approach to Earth on 13 March 2011. Before the 2020 approach, the asteroid had a short observation arc of 4 days and had not been observed since March 2011. The asteroid was expected to pass within 1 lunar distance of Earth in early September 2020, but did not. There was no risk of a 2020 impact because the line of variation (LOV) did not pass through where Earth would be, and the closest possible 2020 Earth approach was about 0.00047 AU (70,000 km; 44,000 mi). One line of variation showed the asteroid passing closest to Earth on 5 September 2020 at 0.06 AU (9,000,000 km; 5,600,000 mi) with a magnitude of 23, which would place it near the limiting magnitude of even the best automated astronomical surveys.
2007 FT3 (also written 2007 FT3) is a lost asteroid with a short observation arc of 1.2 days that cannot be recovered with targeted observations and awaits serendipitous survey observations. It has a poorly constrained orbit and has not been seen since 2007. It was first observed on 20 March 2007 when the asteroid was estimated to be 0.19 ± 0.01 AU (28.4 ± 1.5 million km) from Earth and had a solar elongation of 107 degrees. 2007 FT3 is the fourth largest asteroid with better than a 1-in-2 million cumulative chance of impacting Earth after (29075) 1950 DA, 1979 XB, and 101955 Bennu. With a cumulative Palermo Technical Impact Hazard Scale of -2.63, the poorly known orbit and assumed size place 2007 FT3 third on an unconstrained listing of the Sentry Risk Table.
2017 DB120 (also written 2017 DB120) is a near-Earth object, meaning that it has an orbit which brings it into proximity with Earth. It is an Amor asteroid, meaning that its orbit does not cross Earth's orbit, but its perihelion is close to, but greater than, the aphelion of Earth. It was first observed on February 25, 2017, when the asteroid was less than 1 AU from Earth and had a solar elongation of 169°.
2020 XR is an Apollo near-Earth object and potentially hazardous asteroid roughly 390 meters in diameter. With a 5-day observation arc it was briefly listed as having a 1 in 11,000 chance of impacting Earth on 1 December 2028 placing it at the top of the Sentry Risk Table with a Palermo scale rating of -0.70.
2009 JF1 is a small near-Earth object that should have passed within 0.3 AU (45 million km) of Earth in 2022. On 5 February 2022 the 2009 observations were remeasured greatly reducing the odds of an impact. On 5 January 2024 it had a 1-in-140,000 chance of impacting Earth. It is estimated to be 10-meters in diameter which would make it smaller than the Chelyabinsk meteor. It has a very short observation arc of 1.2 days and has not been observed since 2009. On 5 January 2024 it was nominally expected to be 0.2 AU (30 million km) from Earth but has an uncertainty region of ±23 million km (0.15 AU). The nominal Earth approach was 14 January 2024 and would have had the asteroid only brightening to apparent magnitude 26 which would have made it too faint for automated surveys to detect. With a Palermo scale rating of -4.41, the odds of impact were 26000 times less than the background hazard level for an asteroid of this size.
2022 AE1 is a Tunguska event-sized asteroid, classified as a near-Earth object of the Apollo group, approximately 70 meters (230 feet) in diameter. It was discovered by the Mount Lemmon Survey on 6 January 2022, when it was 0.09 AU (13 million km) from Earth. On 9 January 2022 with an observation arc of 3 days, it was rated with a Torino scale of 1 for a virtual impactor on 4 July 2023 16:28 UTC. Nominal approach is expected to occur 1 July 2023 01:13 ± 1 day. With a Palermo scale rating of as high as –0.66 at the European Space Agency on 11 January 2022, the odds of impact peaked at about 4.6 times less than the background hazard level. NEODyS was the first risk-page to drop to Torino scale 0 on 12 January 2022 followed by ESA on 13 January 2022, but by January 14 both returned to Torino scale 1. On 14 January 2022 the waxing gibbous moon was as little as 3 degrees from the asteroid delaying observations of the asteroid from January 12–19. On 20 January 2022 with a 16-day observation arc, using JPL #11 the Sentry Risk Table dropped the asteroid to Torino scale 0 and then later that day JPL #12 resulted in it being removed from the risk table.
References
- 1 2 3 "MPEC 2002-N38 : 2002 NT7". IAU Minor Planet Center. July 14, 2002. (K02N07T)
- 1 2 3 4 "JPL Small-Body Database Browser: 89959 (2002 NT7)" (2017-03-15 last obs.). Jet Propulsion Laboratory . Retrieved April 26, 2017.
- 1 2 3 "89959 (2002 NT7)". Minor Planet Center. Retrieved April 26, 2017.
- 1 2 Mainzer, A.; Grav, T.; Bauer, J.; Masiero, J.; McMillan, R. S.; Cutri, R. M.; et al. (December 2011). "NEOWISE Observations of Near-Earth Objects: Preliminary Results". The Astrophysical Journal. 743 (2): 17. arXiv: 1109.6400 . Bibcode:2011ApJ...743..156M. doi:10.1088/0004-637X/743/2/156. S2CID 239991 . Retrieved April 26, 2017.
- 1 2 "How A/CC broke the 2002 NT7 story". hohmanntransfer. March 29, 2003. Archived from the original on November 6, 2020. Retrieved April 25, 2019.
- 1 2 3 "JPL Close-Approach Data: 89959 (2002 NT7)" (last observation: 2011-09-12; arc: 57 years). Retrieved November 4, 2011.
- ↑ Asteroid 2002 NT7 Under Watch, But Probably Not Coming Our Way Archived 2006-04-05 at the Wayback Machine (25 July 2002)
- ↑ "Space rock 'on collision course'". BBC News . July 24, 2002. Retrieved December 28, 2007.
- ↑ "Date/Time Removed". NASA/JPL Near-Earth Object Program Office. Archived from the original on June 2, 2002. Retrieved May 6, 2011.
- ↑ "NEODyS-2 Close Approaches for (89959) 2002NT7". Near Earth Objects – Dynamic Site. Retrieved November 5, 2011.
