41P/Tuttle-Giacobini-Kresak's background

Discovery and Subsequent Apparitions

T-G-K was discovered on May 3, 1858 by Horace P. Tuttle, but was lost due to a poor determination of its orbit due to limited observations.

It was rediscovered on June 1, 1907 by Michael Giacobini, but was not immediately linked to the 1858 object, again due to limited observations. By 1928, Andrew Crommelin had linked the 1858 and 1907 apparitions, and predicted returns for 1928 and 1934. Attempts to use this information to recover the comet were unsuccessful, and the comet was considered to be lost.

The comet was again discovered April 24, 1951 by Lubor Kresak and conclusively linked to the other two apparitions. The three independent discoveries over almost a century resulted in the name Tuttle-Giacobini-Kresak.

Since 1951, it has been observed on every favorable apparition. It has exhibited outburst activity, with multiple outbursts on at least two recent apparitions.

Encounters with Jupiter

At aphelion, T-G-K approaches Jupiter's orbit, which inroduces the potential for significant changes in its orbit. However, over the last few apparitions (and future ones), only minor perurbations have occurred.

Date	Distance from Jupiter	Change in Perihelion Distance	Change in Orbital Period
Jun 9, 1975	0.37 AU	1.15 →  1.12 AU	5.56 →  5.58 yr
Feb 16, 1988	0.67 AU	1.12 →  1.07 AU	5.58 →  5.46 yr
Sep 19, 2046	0.52 AU	1.08 →  1.07 AU	5.49 →  5.50 yr

Recent and Upcoming Apparitions

Recent apparitions of comet T-G-K have not brought the comet very close to Earth. That will change on this apparition, where it will approach to within 0.142 AU on April 1, 2017. If it goes into outburst around perihelion, as it has on some of its previous apparitions, then it is likely that T-G-K could reach naked eye brightness.

Many thanks to Gary Kronk and his Cometography books for contributions to this history.