List of unnumbered minor planets: 2003 U (380–429)

This is a partial list of unnumbered minor planets for principal provisional designations assigned during 16–31 October 2003. Since this period yielded a high number of provisional discoveries, it is further split into several standalone pages. , a total of 118 bodies remain unnumbered for this period. Objects for this year are listed on the following pages: A–E · F–G · H–L · M–R · Si · Sii · Siii · Siv · T · Ui · Uii · Uiii · Uiv · V · Wi · Wii and X–Y. Also see previous and next year.

U

|- id="2003 UJ380" bgcolor=#E9E9E9 | – || || MBA-M || 19.1 || data-sort-value="0.64" | 640 m || single || 5 days || 24 Oct 2003 || 6 || align=left | Disc.: SDSS || |- id="2003 UR380" bgcolor=#d6d6d6 | 2 || || HIL || 16.8 || 2.4 km || multiple || 2003–2019 || 28 Nov 2019 || 38 || align=left | Disc.: SDSS || |- id="2003 UT381" bgcolor=#E9E9E9 | 0 || || MBA-M || 18.2 || data-sort-value="0.96" | 960 m || multiple || 2003–2020 || 10 Dec 2020 || 51 || align=left | Disc.: SDSS || |- id="2003 UX381" bgcolor=#fefefe | – || || MBA-I || 20.5 || data-sort-value="0.24" | 240 m || single || 24 days || 24 Oct 2003 || 11 || align=left | Disc.: SDSS || |- id="2003 UE382" bgcolor=#fefefe | 0 || || MBA-I || 19.23 || data-sort-value="0.42" | 420 m || multiple || 1996–2021 || 08 Nov 2021 || 41 || align=left | Disc.: SDSS || |- id="2003 UY382" bgcolor=#d6d6d6 | 0 || || MBA-O || 17.1 || 2.1 km || multiple || 2003–2020 || 27 Jan 2020 || 101 || align=left | Disc.: LONEOSAlt.: 2003 TH59, 2019 SS11 || |- id="2003 UA383" bgcolor=#E9E9E9 | – || || MBA-M || 19.8 || data-sort-value="0.33" | 330 m || single || 4 days || 23 Oct 2003 || 6 || align=left | Disc.: SDSS || |- id="2003 UE383" bgcolor=#fefefe | 0 || || MBA-I || 19.23 || data-sort-value="0.42" | 420 m || multiple || 2003–2021 || 06 Nov 2021 || 44 || align=left | Disc.: SDSSAdded on 5 November 2021 || |- id="2003 UU383" bgcolor=#E9E9E9 | 0 || || MBA-M || 18.7 || data-sort-value="0.54" | 540 m || multiple || 2003–2020 || 24 Dec 2020 || 34 || align=left | Disc.: SDSSAlt.: 2007 RP198 || |- id="2003 UV383" bgcolor=#E9E9E9 | 0 || || MBA-M || 18.44 || 1.1 km || multiple || 2003–2021 || 24 Nov 2021 || 65 || align=left | Disc.: SDSS || |- id="2003 UB384" bgcolor=#d6d6d6 | 0 || || MBA-O || 17.5 || 1.8 km || multiple || 2003–2021 || 04 Jan 2021 || 37 || align=left | Disc.: SDSS || |- id="2003 UD384" bgcolor=#E9E9E9 | 0 || || MBA-M || 19.0 || data-sort-value="0.67" | 670 m || multiple || 2003–2020 || 07 Nov 2020 || 36 || align=left | Disc.: SDSSAlt.: 2020 PW33 || |- id="2003 UK384" bgcolor=#E9E9E9 | 0 || || MBA-M || 18.5 || data-sort-value="0.84" | 840 m || multiple || 2003–2020 || 18 Oct 2020 || 51 || align=left | Disc.: SDSS || |- id="2003 UP384" bgcolor=#fefefe | 3 || || MBA-I || 19.59 || data-sort-value="0.33" | 330 m || multiple || 2003-2022 || 22 Sep 2022 || 20 || align=left | Disc.: SDSS || |- id="2003 US384" bgcolor=#d6d6d6 | 0 || || MBA-O || 17.1 || 2.1 km || multiple || 2003–2019 || 26 Nov 2019 || 37 || align=left | Disc.: SDSS || |- id="2003 UX384" bgcolor=#E9E9E9 | 3 || || MBA-M || 18.4 || 1.2 km || multiple || 2003–2017 || 09 Dec 2017 || 26 || align=left | Disc.: SDSSAlt.: 2017 XB47 || |- id="2003 UC385" bgcolor=#d6d6d6 | 2 || || HIL || 16.9 || 2.3 km || multiple || 2003–2019 || 24 Dec 2019 || 37 || align=left | Disc.: SDSS || |- id="2003 UF385" bgcolor=#d6d6d6 | 0 || || MBA-O || 18.1 || 1.3 km || multiple || 2003–2018 || 03 Nov 2018 || 42 || align=left | Disc.: SDSSAlt.: 2008 UE86 || |- id="2003 UJ385" bgcolor=#E9E9E9 | 0 || || MBA-M || 17.8 || data-sort-value="0.82" | 820 m || multiple || 2003–2020 || 17 Dec 2020 || 24 || align=left | Disc.: SDSSAlt.: 2007 RA255 || |- id="2003 UO385" bgcolor=#E9E9E9 | 2 || || MBA-M || 19.0 || data-sort-value="0.67" | 670 m || multiple || 2003–2020 || 14 Nov 2020 || 28 || align=left | Disc.: SDSS || |- id="2003 UJ386" bgcolor=#E9E9E9 | 1 || = (887254) || MBA-M || 18.30 || 1.2 km || multiple || 2003–2021 || 06 Oct 2021 || 48 || align=left | Disc.: SDSSAdded on 5 November 2021 || |- id="2003 UQ386" bgcolor=#d6d6d6 | 0 || || MBA-O || 17.7 || 1.6 km || multiple || 2003–2020 || 27 Jan 2020 || 36 || align=left | Disc.: SDSSAdded on 22 July 2020Alt.: 2015 AT228 || |- id="2003 UD387" bgcolor=#fefefe | 0 || || MBA-I || 19.3 || data-sort-value="0.41" | 410 m || multiple || 2003–2020 || 19 Oct 2020 || 24 || align=left | Disc.: SDSSAdded on 17 January 2021 || |- id="2003 UL387" bgcolor=#d6d6d6 | 0 || || MBA-O || 17.18 || 2.0 km || multiple || 2003–2021 || 28 Nov 2021 || 38 || align=left | Disc.: SDSSAdded on 19 October 2020 || |- id="2003 UQ387" bgcolor=#fefefe | 0 || || MBA-I || 18.47 || data-sort-value="0.60" | 600 m || multiple || 2003–2022 || 26 Jan 2022 || 53 || align=left | Disc.: SDSS || |- id="2003 UV387" bgcolor=#E9E9E9 | 0 || || MBA-M || 17.14 || 2.1 km || multiple || 2003–2021 || 28 Oct 2021 || 42 || align=left | Disc.: SDSSAdded on 30 September 2021 || |- id="2003 UZ387" bgcolor=#d6d6d6 | 0 || || MBA-O || 17.4 || 1.8 km || multiple || 2003–2019 || 26 Nov 2019 || 25 || align=left | Disc.: SDSSAdded on 17 January 2021 || |- id="2003 UA388" bgcolor=#fefefe | 2 || || MBA-I || 19.4 || data-sort-value="0.39" | 390 m || multiple || 2003–2019 || 28 Nov 2019 || 18 || align=left | Disc.: SDSS || |- id="2003 UK388" bgcolor=#fefefe | 0 || || MBA-I || 18.83 || data-sort-value="0.51" | 510 m || multiple || 2003–2021 || 10 Nov 2021 || 49 || align=left | Disc.: SDSSAdded on 22 July 2020Alt.: 2014 WX458 || |- id="2003 UP388" bgcolor=#E9E9E9 | 0 || || MBA-M || 18.26 || data-sort-value="0.94" | 940 m || multiple || 2003–2021 || 08 Dec 2021 || 46 || align=left | Disc.: SDSS || |- id="2003 UU388" bgcolor=#fefefe | 0 || || MBA-I || 18.80 || data-sort-value="0.52" | 520 m || multiple || 2003–2021 || 27 Nov 2021 || 55 || align=left | Disc.: SpacewatchAdded on 5 November 2021Alt.: 2021 RB70 || |- id="2003 UF389" bgcolor=#E9E9E9 | 0 || || MBA-M || 18.6 || data-sort-value="0.80" | 800 m || multiple || 2003–2020 || 20 Oct 2020 || 37 || align=left | Disc.: SDSSAdded on 17 January 2021 || |- id="2003 UH389" bgcolor=#d6d6d6 | 1 || || MBA-O || 17.4 || 1.8 km || multiple || 2003–2020 || 10 Dec 2020 || 52 || align=left | Disc.: SDSS || |- id="2003 UA390" bgcolor=#E9E9E9 | 1 || || MBA-M || 18.50 || 1.1 km || multiple || 2003–2021 || 31 Oct 2021 || 37 || align=left | Disc.: SDSSAdded on 5 November 2021 || |- id="2003 UN390" bgcolor=#E9E9E9 | 1 || || MBA-M || 18.9 || data-sort-value="0.49" | 490 m || multiple || 2003–2015 || 03 Oct 2015 || 29 || align=left | Disc.: SDSSAlt.: 2015 PV79 || |- id="2003 UR390" bgcolor=#fefefe | 0 || || MBA-I || 18.9 || data-sort-value="0.49" | 490 m || multiple || 2003–2019 || 06 Jul 2019 || 28 || align=left | Disc.: SDSSAdded on 17 January 2021 || |- id="2003 US390" bgcolor=#d6d6d6 | 0 || || MBA-O || 17.7 || 1.6 km || multiple || 2003–2019 || 21 Oct 2019 || 21 || align=left | Disc.: SDSS || |- id="2003 UX390" bgcolor=#fefefe | 0 || || MBA-I || 18.9 || data-sort-value="0.49" | 490 m || multiple || 2003–2020 || 08 Dec 2020 || 39 || align=left | Disc.: SDSS || |- id="2003 UY391" bgcolor=#E9E9E9 | 0 || || MBA-M || 18.3 || 1.2 km || multiple || 2003–2018 || 05 Jan 2018 || 63 || align=left | Disc.: SDSS || |- id="2003 UZ391" bgcolor=#fefefe | 0 || || MBA-I || 18.3 || data-sort-value="0.65" | 650 m || multiple || 2003–2020 || 05 Mar 2020 || 45 || align=left | Disc.: SDSS || |- id="2003 UC392" bgcolor=#fefefe | 1 || || MBA-I || 18.8 || data-sort-value="0.52" | 520 m || multiple || 2003–2021 || 30 Nov 2021 || 39 || align=left | Disc.: SDSS || |- id="2003 UD392" bgcolor=#d6d6d6 | 0 || || MBA-O || 17.48 || 1.8 km || multiple || 2003–2021 || 15 Apr 2021 || 48 || align=left | Disc.: SDSSAlt.: 2015 AJ172 || |- id="2003 UR392" bgcolor=#d6d6d6 | 1 || || MBA-O || 17.3 || 1.9 km || multiple || 2003–2019 || 28 Sep 2019 || 25 || align=left | Disc.: SDSS || |- id="2003 UU392" bgcolor=#d6d6d6 | 0 || || MBA-O || 17.91 || 1.5 km || multiple || 2003-2022 || 20 Oct 2022 || 69 || align=left | Disc.: SDSS || |- id="2003 UC393" bgcolor=#E9E9E9 | 0 || || MBA-M || 18.2 || data-sort-value="0.96" | 960 m || multiple || 2003–2011 || 01 Aug 2011 || 18 || align=left | Disc.: Kitt Peak Obs.Alt.: 2011 OM47 || |- id="2003 UD393" bgcolor=#E9E9E9 | 2 || || MBA-M || 19.0 || data-sort-value="0.47" | 470 m || multiple || 2003–2019 || 29 Oct 2019 || 41 || align=left | Disc.: SDSS || |- id="2003 US393" bgcolor=#d6d6d6 | 0 || || MBA-O || 17.8 || 1.5 km || multiple || 2003–2018 || 07 Sep 2018 || 17 || align=left | Disc.: SDSS || |- id="2003 UL395" bgcolor=#E9E9E9 | 1 || || MBA-M || 18.1 || data-sort-value="0.71" | 710 m || multiple || 2003–2019 || 29 Oct 2019 || 18 || align=left | Disc.: SDSS || |- id="2003 UK396" bgcolor=#E9E9E9 | 0 || || MBA-M || 19.1 || data-sort-value="0.45" | 450 m || multiple || 2003–2019 || 19 Dec 2019 || 79 || align=left | Disc.: SDSSAlt.: 2015 TB141 || |- id="2003 UQ396" bgcolor=#E9E9E9 | 0 || || MBA-M || 17.9 || 1.1 km || multiple || 2003–2020 || 17 Nov 2020 || 25 || align=left | Disc.: SDSSAdded on 21 August 2021 || |- id="2003 UV396" bgcolor=#E9E9E9 | 2 || || MBA-M || 19.4 || data-sort-value="0.55" | 550 m || multiple || 2003–2016 || 25 Oct 2016 || 15 || align=left | Disc.: SDSS || |- id="2003 UY397" bgcolor=#E9E9E9 | 0 || || MBA-M || 18.0 || 1.1 km || multiple || 2003–2020 || 20 Dec 2020 || 41 || align=left | Disc.: SDSSAdded on 17 January 2021 || |- id="2003 UA398" bgcolor=#E9E9E9 | 0 || || MBA-M || 17.89 || 1.5 km || multiple || 2003–2021 || 04 Dec 2021 || 51 || align=left | Disc.: SDSSAdded on 24 December 2021 || |- id="2003 UK398" bgcolor=#FA8072 | 0 || || MCA || 19.08 || data-sort-value="0.45" | 450 m || multiple || 2003–2021 || 29 Nov 2021 || 31 || align=left | Disc.: SDSSAdded on 21 August 2021 || |- id="2003 UV398" bgcolor=#E9E9E9 | 1 || || MBA-M || 18.5 || data-sort-value="0.59" | 590 m || multiple || 2003–2019 || 26 Sep 2019 || 41 || align=left | Disc.: SDSS || |- id="2003 UY398" bgcolor=#E9E9E9 | 1 || || MBA-M || 18.34 || 1.2 km || multiple || 2003–2021 || 23 Nov 2021 || 35 || align=left | Disc.: SDSSAdded on 5 November 2021 || |- id="2003 UL401" bgcolor=#fefefe | 1 || || MBA-I || 19.0 || data-sort-value="0.47" | 470 m || multiple || 2003–2017 || 14 Sep 2017 || 32 || align=left | Disc.: SDSSAdded on 17 January 2021Alt.: 2017 PW15 || |- id="2003 UR401" bgcolor=#E9E9E9 | – || || MBA-M || 19.4 || data-sort-value="0.39" | 390 m || single || 36 days || 24 Oct 2003 || 13 || align=left | Disc.: SDSS || |- id="2003 UV401" bgcolor=#d6d6d6 | 0 || || MBA-O || 17.3 || 1.9 km || multiple || 2003–2019 || 02 Dec 2019 || 30 || align=left | Disc.: SDSS || |- id="2003 UW401" bgcolor=#E9E9E9 | 4 || || MBA-M || 18.4 || data-sort-value="0.88" | 880 m || multiple || 2003–2012 || 10 Dec 2012 || 16 || align=left | Disc.: LPL/Spacewatch IIAdded on 5 November 2021Alt.: 2012 XV174 || |- id="2003 UJ402" bgcolor=#fefefe | 2 || || MBA-I || 19.78 || data-sort-value="0.36" | 360 m || multiple || 2003-2021 || 24 Oct 2003 || 34 || align=left | Disc.: SDSS || |- id="2003 UQ402" bgcolor=#fefefe | 0 || || MBA-I || 18.92 || data-sort-value="0.49" | 490 m || multiple || 2003–2021 || 29 Nov 2021 || 61 || align=left | Disc.: Kitt Peak Obs.Alt.: 2006 KB138 || |- id="2003 UW402" bgcolor=#fefefe | 3 || || MBA-I || 19.0 || data-sort-value="0.47" | 470 m || multiple || 2003–2014 || 19 Sep 2014 || 36 || align=left | Disc.: SDSSAlt.: 2014 RJ39 || |- id="2003 UF403" bgcolor=#fefefe | 0 || || MBA-I || 18.9 || data-sort-value="0.49" | 490 m || multiple || 2003–2018 || 10 Nov 2018 || 39 || align=left | Disc.: SDSS || |- id="2003 UM403" bgcolor=#fefefe | 0 || || MBA-I || 18.9 || data-sort-value="0.49" | 490 m || multiple || 2003–2018 || 18 Aug 2018 || 27 || align=left | Disc.: SDSS || |- id="2003 UN403" bgcolor=#E9E9E9 | 1 || || MBA-M || 18.9 || data-sort-value="0.49" | 490 m || multiple || 2003–2019 || 15 Jun 2019 || 36 || align=left | Disc.: SDSS || |- id="2003 UO403" bgcolor=#E9E9E9