 Mosaic of radar images of2003 YT1 and its moon byArecibo Observatory on 4 May 2004 | |
| Discovery[1] | |
|---|---|
| Discovered by | Catalina Sky Srvy. |
| Discovery site | Catalina Stn. |
| Discovery date | 18 December 2003 |
| Designations | |
| (164121)2003 YT1 | |
| 2003 YT1 | |
| Apollo · NEO · PHA[1][2] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 35.41yr (12,934 d) |
| Aphelion | 1.4335AU |
| Perihelion | 0.7857 AU |
| 1.1096 AU | |
| Eccentricity | 0.2919 |
| 1.17 yr (427 d) | |
| 11.417° | |
| 0° 50m 35.88s / day | |
| Inclination | 44.064° |
| 38.335° | |
| 91.042° | |
| Knownsatellites | 1(D: 210 m;P: 30 h)[3][4] |
| Earth MOID | 0.0027 AU (1.0519LD) |
| Physical characteristics | |
| 1.0 km[3] 1.100±0.088 km[5] 1.561±0.202 km[6] 1.717±0.550 km[7] | |
| 2.34 h[8] 2.343 h[3] 2.343 h[9] 3.0025±0.0001 h[10] | |
| 0.198±0.153[7] 0.240±0.067[6] 0.36±0.20[11] 0.486±0.040[11] 0.4861±0.0395[5] 0.5848(derived)[12] | |
| V[12][13][14] | |
| 16.2[2][5][12] 16.20±0.3[7] | |
(164121) 2003 YT1, provisional designation2003 YT1, is a brightasteroid and synchronousbinary system on a highly eccentric orbit, classified asnear-Earth object andpotentially hazardous asteroid of theApollo group, approximately 2 kilometers (1.2 miles) in diameter. It was discovered on 18 December 2003, by astronomers with theCatalina Sky Survey at theCatalina Station near Tucson, Arizona, in the United States.[1] TheV-type asteroid has a shortrotation period of 2.3 hours.[12] Its 210-meter sizedminor-planet moon was discovered atArecibo Observatory in May 2004.[3][4]
2003 YT1 is a member of theEarth-crossing group ofApollo asteroids, the largest group ofnear-Earth objects with approximately 10 thousand known members.[1][2]
It orbits the Sun at a distance of 0.8–1.4 AU once every 1 years and 2 months (427 days;semi-major axis of 1.11 AU). Its orbit has aneccentricity of 0.29 and aninclination of 44° with respect to theecliptic.[2] The body'sobservation arc begins with aprecovery taken at theSiding Spring Observatory in November 1989, more than 14 years prior to its official discovery observation at Catalina.[1]
The asteroid has an Earthminimum orbital intersection distance of 0.0027 AU (404,000 km; 251,000 mi), which corresponds to 1.05lunar distances and makes it apotentially hazardous asteroid due to its sufficiently large size.[2] On theTorino Scale, this object was rated level 1 on 27 December 2003 with an observation arc of 8.7 days.[15] It was removed from the risk table on 29 December 2003.[16] Over the next ten million years the asteroid has a 6% chance of impacting Earth.[17]
On 30 April 2004 it made a close approach at a nominal distance of 0.073 AU (28 LD), and on 31 October 2016, it passed Earth at 0.035 AU (14 LD). The asteroid's closest encounter with Earth will be on 29 April 2073, when it is projected to pass at 0.0113 AU (4.4 LD) only(see table).[2]
2003 YT1 has unique orbital characteristics among minor planets. It is the only known binary asteroid to have an Earth MOID within the Moon's Apogee.[18]
| Date | JPL Horizons nominal geocentric distance (AU) | uncertainty region (3-sigma) |
|---|---|---|
| 2023-Nov-03 12:33 | 0.05936 AU (8.880 million km)[2] | ±18 km[19] |
| 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 5lunar distances (LD) of objects withH 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 onH andalbedo range between X and Y. (D) Reference: data source from theJPL SBDB, withAU converted into LD (1 AU≈390 LD) (E) Color codes: unobserved at close approach observed during close approach upcoming approaches | |||||||
On 28 April 2017, a 2.7 cm (1 in) fragment of2013 YT1 is suspected of havingimpacted Earth creating afireball over Kyoto, Japan.[17] The fragment would have broken off the parent body within the last ten thousand years.
This object has been characterized as a bright Vestian-likeV-type asteroid.[12][14][13]
Several rotationallightcurve of this asteroid have been obtained fromphotometric observations (U=2/n.a./3/3).[8][3][9][10] Analysis of the best-rated lightcurve gave a shortrotation period of 2.343 hours with a brightness amplitude between 0.16 and 0.27magnitude.[12]
According to radar observations with theArecibo Observatory and the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer, this asteroid measures between 1.0 and 1.717 kilometers in diameter and its surface has analbedo between 0.198 and 0.4861.[3][5][6][7][11]
TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.5848 and adopts a diameter of 1.0 kilometer based on anabsolute magnitude of 16.2.[12]
The Arecibo radar observations in May 2004 revealed that2003 YT1 is a synchronousbinary asteroid.[3] Follow-up observations confirmed a 210-meter sizedminor-planet moon orbiting its primary every 30 hours at a distance of 2.7 km.[4][9]
Thisminor planet wasnumbered by theMinor Planet Center on 26 September 2007 (M.P.C. 60686).[20] As of 2018, it has not beennamed.[1]
