|-id=773 bgcolor=#E9E9E9 | 21773 || || — || September 7, 1999 || Socorro || LINEAR || CLO || align=right | 4.2 km || |-id=774 bgcolor=#fefefe | 21774 O'Brien || || || September 3, 1999 || Anderson Mesa || LONEOS || V || align=right | 1.7 km || |-id=775 bgcolor=#fefefe | 21775 Tsiganis || || || September 5, 1999 || Anderson Mesa || LONEOS || — || align=right | 3.1 km || |-id=776 bgcolor=#E9E9E9 | 21776 Kryszczyńska || || || September 5, 1999 || Anderson Mesa || LONEOS || — || align=right | 3.5 km || |-id=777 bgcolor=#d6d6d6 | 21777 || || — || September 5, 1999 || Catalina || CSS || EOS || align=right | 6.0 km || |-id=778 bgcolor=#fefefe | 21778 Andrewarren || || || September 7, 1999 || Socorro || LINEAR || MAS || align=right | 2.9 km || |-id=779 bgcolor=#E9E9E9 | 21779 || || — || September 8, 1999 || Catalina || CSS || — || align=right | 3.1 km || |-id=780 bgcolor=#fefefe | 21780 || || — || September 8, 1999 || Catalina || CSS || — || align=right | 3.3 km || |-id=781 bgcolor=#fefefe | 21781 || || — || September 8, 1999 || Catalina || CSS || — || align=right | 2.2 km || |-id=782 bgcolor=#fefefe | 21782 Davemcdonald || || || September 8, 1999 || Anderson Mesa || LONEOS || FLO || align=right | 2.3 km || |-id=783 bgcolor=#E9E9E9 | 21783 || || — || September 7, 1999 || Kitt Peak || Spacewatch || — || align=right | 3.4 km || |-id=784 bgcolor=#E9E9E9 | 21784 || || — || September 17, 1999 || Višnjan Observatory || K. Korlević || — || align=right | 5.6 km || |-id=785 bgcolor=#E9E9E9 | 21785 Méchain || || || September 21, 1999 || Kleť || M. Tichý || — || align=right | 4.5 km || |-id=786 bgcolor=#d6d6d6 | 21786 || || — || September 29, 1999 || Višnjan Observatory || K. Korlević || — || align=right | 12 km || |-id=787 bgcolor=#E9E9E9 | 21787 || || — || September 29, 1999 || Višnjan Observatory || K. Korlević || EUN || align=right | 6.2 km || |-id=788 bgcolor=#FA8072 | 21788 || || — || September 30, 1999 || Socorro || LINEAR || PHO || align=right | 3.3 km || |-id=789 bgcolor=#fefefe | 21789 Frankwasser || || || September 29, 1999 || Socorro || LINEAR || FLO || align=right |