# (35396) 1997 XF11

(35396) 1997 XF$_{11}$ (provisional designation 1997 XF$_{11}$) is a kilometer-sized asteroid, classified as a near-Earth object, Mars-crosser and potentially hazardous asteroid of the Apollo group.
2028 Earth/Moon approach :
| Date & Time | Approach to | Nominal distance | uncertainty region (3-sigma) |
| 2028-Oct-26 06:44 | Earth | 929253 km | ± 106 km |
| 2028-Oct-26 07:39 | Moon | 1326430 km | ± 106 km |

## Description

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). During the close approach, the asteroid should peak at about apparent magnitude 8.2, and will be visible in binoculars.
1997 XF$_{11}$ measures between 0.7 and 1.4 kilometers in diameter.
This asteroid also regularly comes near the large asteroid Pallas.

### IAU Circular

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." But by 23 December 1997, it was clear that XF11 had no reasonable possibility of an Earth impact. Many news outlets mistakenly emphasized the possibility of disaster.
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. 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. During the October 2002 close approach, the asteroid was observed by the 70-meter Goldstone radar dish, further refining the orbit.
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| PHA | Date | Approach distance (lunar dist.) | Approach distance (lunar dist.) | Approach distance (lunar dist.) | Abs. mag (H) | Diameter $^{(C)}$ (m) | Ref $^{(D)}$ |
| PHA | Date | Nomi- nal$^{(B)}$ | Mini- mum | Maxi- mum | Abs. mag (H) | Diameter $^{(C)}$ (m) | Ref $^{(D)}$ |
| (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 ||||||||