Lost Asteroid - 20th-century Recoveries - 1980s and 1990s

1980s and 1990s

L. K. Kristensen at the University of Aarhus rediscovered 452 Hamiltonia and 1537 Transylvania, along with numerous other small objects, in 1981. At the time these results were published, only nine numbered minor planets remained unobserved since their discoveries: 330 Adalberta, 473 Nolli, 719 Albert, 724 Hapag, 843 Nicolaia, 878 Mildred, 1009 Sirene, 1026 Ingrid, and 1179 Mally.

843 Nicolaia was rediscovered at the Heidelberg Astronomisches Rechen-Institut in 1981.

473 Nolli was discovered by Max Wolf on 13 February 1901, but it remained lost for many decades until it was recovered finally in 1987 IAUC 4292, 86 years later.

878 Mildred was originally discovered in 1916 using the 1.5 m (60-inch) Hale Telescope at the Mount Wilson Observatory, but was subsequently lost until it was again observed on single nights in 1985 and 1991.

724 Hapag and 719 Albert had first been found by Johann Palisa in 1911. Hapag was given the provisional name 1911 NC, but lost until it was rediscovered in 1988. Due to inaccuracies in its computed orbit, Albert was also lost and not recovered until 2000, when Jeffrey A. Larsen located it using data from the Spacewatch asteroid survey project. At the time of its rediscovery, Albert was the last remaining "lost asteroid" among those assigned numbers (69230 Hermes was not numbered until 2003).

1009 Sirene was recovered in 1982 by J. Gibson using exposures form the 48-inch (120 cm) Schmidt telescope at Palomar Observatory, and he revised its ephemeris.

1026 Ingrid was discovered by Karl Wilhelm Reinmuth on 13 August 1923 and given the provisional designation 1923 NY. It was reidentified in 1986 by Syuichi Nakano.

1179 Mally was discovered by Max Wolf on 19 March 1931 and given the provisional designation 1931 FD. It was rediscovered in 1986 by Lutz D. Schmadel, Richard Martin West and Hans-Emil Schuster.

While studying in Chicago in 1928, Zhang Yuzhe discovered an asteroid that was given the provisional designation 1928 UF, and later the number 1125. He named it "China" or "中華" (Zhōnghuá). However, this asteroid was not observed beyond its initial appearance and a precise orbit could not be calculated. In 1957, the Purple Mountain Observatory in China discovered a new asteroid, and with Zhang Yuzhe's agreement the new object 1957 UN₁ was re-assigned the official designation 1125 China in place of the lost 1928 UF. However, in 1986, the newly discovered object 1986 QK₁ was confirmed to be a rediscovery of the original 1928 UF, and this object was named 3789 Zhongguo (also a name for China).

Asteroid (29075) 1950 DA was discovered on 23 February 1950 by Carl A. Wirtanen at Lick Observatory. It was observed for 17 days and then lost, since not enough observations were made to allow its orbit to be plotted. It was then rediscovered on 31 December 2000. The chance it will impact Earth on 16 March 2880 during its close approach has been estimated as 1 in 300, roughly 50% greater than that for all other such objects combined between now and 2880. It has a diameter of about a kilometer (.6 miles).

7796 Járacimrman was discovered at Kleť Observatory (Czech Republic) on 16 January 1996 by Zdeněk Moravec and was designated 1996 BG. It was observed until April 1996 and then in June and July 1997. It was revealed, by precovery, to be a lost asteroid which had previously been observed twice: at the Brera-Merate Observatory in northern Italy on 12 December 1973 and at Mount Stromlo Observatory (near Canberra, Australia) on 8 and 9 July 1990.