(35396) 1997 XF11 (provisional designation 1997 XF11) is a kilometer-sized asteroid, classified as a near-Earth object, Mars-crosser and potentially hazardous asteroid of the Apollo group.[1]

(35396) 1997 XF11
Discovery[1][2]
Discovered bySpacewatch
Discovery siteKitt Peak National Obs.
Discovery date6 December 1997
Designations
(35396) 1997 XF11
1997 XF11
Orbital characteristics[3]
Epoch 13 September 2023
(JD 2453300.5)
Uncertainty parameter 0
Observation arc33.19 yr (12,121 days)
Aphelion2.139 AU (320.0 million km)
Perihelion0.7446 AU (111.39 million km)
1.442 AU (215.7 million km)
Eccentricity0.48369
1.73 yr (633 days)
44.44°
0° 34m 7.68s / day
Inclination4.0995°
213.65°
26 June 2023
103.06°
Earth MOID0.0003 AU (45 thousand km)
Physical characteristics
  • 0.704±0.103 km[4]
  • 0.940±0.480 km[5]
  • 1.39 km (derived)[6]
  • 3.252±0.002 h[7]
  • 3.253±0.002 h[8]
  • 3.2566±0.0002 h[9]
  • 3.25765±0.00005 h[10]
  • 3.259 h[6]
  • 3.2591±0.0025 h[6]
  • 0.18 (assumed)[6]
  • 0.29±0.21[5]
  • 0.7727±0.2436[4]
2028 Earth/Moon approach[3]
Date & Time Approach
to
Nominal distance uncertainty
region
(3-sigma)
2028-Oct-26 06:44 Earth 929253 km ± 106 km[13]
2028-Oct-26 07:39 Moon 1326430 km ± 106 km

Description

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Three months after its discovery on 6 December 1997 by James V. Scotti of the University of Arizona's Spacewatch Project, the asteroid was predicted to make an exceptionally close approach to Earth on 28 October 2028. Additional precovery observations of the asteroid from 1990 were quickly found that refined the orbit and it is now known the asteroid will pass Earth on 26 October 2028, at a distance of 929,000 km (2.42 LD).[3][14][15] During the close approach, the asteroid should peak at about apparent magnitude 8.2,[16] and will be visible in binoculars.[17]

1997 XF11 measures between 0.7 and 1.4 kilometers in diameter.[6][4][5]

This asteroid also regularly comes near the large asteroid Pallas.[15]

IAU Circular

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On 11 March 1998, using a three-month observation arc, a faulty International Astronomical Union circular and press information sheet were put out that incorrectly concluded "that the asteroid was 'virtually certain' to pass within 80% of the distance to the Moon and stood a 'small...not entirely out of the question' possibility of hitting the Earth in 2028."[18] But by 23 December 1997, it should have been clear that XF11 had no reasonable possibility of an Earth impact.[18] Many news outlets mistakenly emphasized the possibility of disaster.[19]

Within hours of the announcement, independent calculations by Paul Chodas, Don Yeomans, and Karri Muinonen had calculated that the probability of Earth impact was essentially zero, and vastly less than the probability of impact from as-yet-undiscovered asteroids.[18] Chodas (1999) concurs with Marsden (1999) that based on the 1997 data alone there was about 1 chance in a hundred thousand that XF11 could have been on an Earth-impact trajectory—that is, until the 1990 precovery observations eliminated such possibilities.[20] During the October 2002 close approach, the asteroid was observed by the 70-meter Goldstone radar dish, further refining the orbit.[17]

History of close approaches of large near-Earth objects since 1908 (A)
PHA Date Approach distance (lunar dist.) Abs.
mag

(H)
Diameter (C)
(m)
Ref (D)
Nomi-
nal(B)
Mini-
mum
Maxi-
mum
(33342) 1998 WT24 1908-12-16 3.542 3.537 3.547 17.9 556–1795 data
(458732) 2011 MD5 1918-09-17 0.911 0.909 0.913 17.9 556–1795 data
(7482) 1994 PC1 1933-01-17 2.927 2.927 2.928 16.8 749–1357 data
69230 Hermes 1937-10-30 1.926 1.926 1.927 17.5 668–2158 data
69230 Hermes 1942-04-26 1.651 1.651 1.651 17.5 668–2158 data
(137108) 1999 AN10 1946-08-07 2.432 2.429 2.435 17.9 556–1795 data
(33342) 1998 WT24 1956-12-16 3.523 3.523 3.523 17.9 556–1795 data
(163243) 2002 FB3 1961-04-12 4.903 4.900 4.906 16.4 1669–1695 data
(192642) 1999 RD32 1969-08-27 3.627 3.625 3.630 16.3 1161–3750 data
(143651) 2003 QO104 1981-05-18 2.761 2.760 2.761 16.0 1333–4306 data
2017 CH1 1992-06-05 4.691 3.391 6.037 17.9 556–1795 data
(170086) 2002 XR14 1995-06-24 4.259 4.259 4.260 18.0 531–1714 data
(33342) 1998 WT24 2001-12-16 4.859 4.859 4.859 17.9 556–1795 data
4179 Toutatis 2004-09-29 4.031 4.031 4.031 15.3 2440–2450 data
2014 JO25 2017-04-19 4.573 4.573 4.573 17.8 582–1879 data
(137108) 1999 AN10 2027-08-07 1.014 1.010 1.019 17.9 556–1795 data
(35396) 1997 XF11 2028-10-26 2.417 2.417 2.418 16.9 881–2845 data
(154276) 2002 SY50 2071-10-30 3.415 3.412 3.418 17.6 714–1406 data
(164121) 2003 YT1 2073-04-29 4.409 4.409 4.409 16.2 1167–2267 data
(385343) 2002 LV 2076-08-04 4.184 4.183 4.185 16.6 1011–3266 data
(52768) 1998 OR2 2079-04-16 4.611 4.611 4.612 15.8 1462–4721 data
(33342) 1998 WT24 2099-12-18 4.919 4.919 4.919 17.9 556–1795 data
(85182) 1991 AQ 2130-01-27 4.140 4.139 4.141 17.1 1100 data
314082 Dryope 2186-07-16 3.709 2.996 4.786 17.5 668–2158 data
(137126) 1999 CF9 2192-08-21 4.970 4.967 4.973 18.0 531–1714 data
(290772) 2005 VC 2198-05-05 1.951 1.791 2.134 17.6 638–2061 data
(A) List includes near-Earth approaches of less than 5 lunar distances (LD) of objects with H brighter than 18.
(B) Nominal geocentric distance from the Earth's center to the object's center (Earth radius≈0.017 LD).
(C) Diameter: estimated, theoretical mean-diameter based on H and albedo range between X and Y.
(D) Reference: data source from the JPL SBDB, with AU converted into LD (1 AU≈390 LD)
(E) Color codes:   unobserved at close approach   observed during close approach   upcoming approaches

References

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  1. ^ a b c "35396 (1997 XF11)". Minor Planet Center. Retrieved 18 January 2018.
  2. ^ "MPEC 1997-Y11 : 1997 XF11". IAU Minor Planet Center. 23 December 1997. Retrieved 8 February 2012. (J97X11F)
  3. ^ a b c d e f "JPL Small-Body Database Browser: 35396 (1997 XF11)" (2023-05-29 last obs.). Jet Propulsion Laboratory. Retrieved 21 September 2023.
  4. ^ a b c d Masiero, Joseph R.; Nugent, C.; Mainzer, A. K.; Wright, E. L.; Bauer, J. M.; Cutri, R. M.; et al. (October 2017). "NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos". The Astronomical Journal. 154 (4): 10. arXiv:1708.09504. Bibcode:2017AJ....154..168M. doi:10.3847/1538-3881/aa89ec. S2CID 45334910.
  5. ^ a b c d Trilling, David E.; Mommert, Michael; Hora, Joseph; Chesley, Steve; Emery, Joshua; Fazio, Giovanni; et al. (December 2016). "NEOSurvey 1: Initial Results from the Warm Spitzer Exploration Science Survey of Near-Earth Object Properties". The Astronomical Journal. 152 (6): 10. arXiv:1608.03673. Bibcode:2016AJ....152..172T. doi:10.3847/0004-6256/152/6/172. S2CID 56105212.
  6. ^ a b c d e f g h "LCDB Data for (35396)". Asteroid Lightcurve Database (LCDB). Retrieved 18 January 2018.
  7. ^ Martinez, Vicente Mas; Silva, Gonzalo Fornas; Martinez, Angel Flores; Garceran, Alfonso Carreno; Mansego, Enrique Arce; Rodriguez, Pedro Brines; et al. (October 2016). "Lightcurves for Two Near-Earth Asteroids by Asteroids Observers (OBAS) - MPPD: 2016 April-May". The Minor Planet Bulletin. 43 (4): 283–284. Bibcode:2016MPBu...43..283M. ISSN 1052-8091.
  8. ^ Warner, Brian D. (October 2016). "Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2016 April-July". The Minor Planet Bulletin. 43 (4): 311–319. Bibcode:2016MPBu...43..311W. ISSN 1052-8091.
  9. ^ Slivan, Stephen M.; Bowsher, Emily C.; Chang, Bena W. (December 2002). "Rotation period and spin direction of near-Earth asteroid (35396) 1997 XF11". The Minor Planet Bulletin. 30 (2): 29–30. Bibcode:2003MPBu...30...29S. ISSN 1052-8091.
  10. ^ Behrend, Raoul. "Asteroids and comets rotation curves – (35396)". Geneva Observatory. Retrieved 18 January 2018.
  11. ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 – Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. S2CID 53493339.
  12. ^ Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026.
  13. ^ "Horizons Batch for 2028-10-26 Close Approach". JPL Horizons. Archived from the original on 12 January 2023. Retrieved 12 January 2023. RNG_3sigma = uncertainty range in km.
  14. ^ Piero Sicoli; Francesco Manca. "Sormano Astronomical Observatory: Table of Next Closest Approaches to the Earth by Asteroids". Astronomical Observatory of Brera. Archived from the original on 1 December 2007. Retrieved 4 February 2008.
  15. ^ a b "NEODyS (35396) 1997XF11 Close Approaches". Department of Mathematics, University of Pisa, ITALY. Archived from the original on 3 March 2016. Retrieved 4 February 2008.
  16. ^ "1997XF11 Ephemerides for 26 Oct 2028". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 16 October 2011.
  17. ^ a b "Halloween Asteroid". 31 October 2002. Retrieved 9 February 2012.
  18. ^ a b c Clark R. Chapman (5 April 1998). "The Asteroid Impact Scare of Mid-March 1998" (last update: 3 September 1998). Southwest Research Institute (SwRI). Retrieved 8 February 2012.
  19. ^ "Twenty Years of Tracking Near-Earth Objects". NASA Jet Propulsion Laboratory (JPL). Retrieved 23 July 2024.
  20. ^ Clark R. Chapman (19 August 1999). "The AsteroidsComet Impact Hazard". Southwest Research Institute (SwRI). Retrieved 9 February 2012.
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