The story starts with a comet that touches the Earth in its flight and collects a few small chunks of it. Some forty people of various nations and ages are condemned to a two-year-long journey on the comet. They form a mini-society and coping with the hostile environment of the comet (mostly the cold). The size of the 'comet' is about 2300 kilometers in diameter - far larger than any comet or asteroid that actually exists.
The English translation by Ellen E. Frewer, was published in England by Sampson Low (November 1877), and the U.S. by Scribner Armstrong with the title Hector Servadac; Or the Career of a Comet. The Frewer translation alters the text considerably with additions and emendations, paraphrases dialogue, and rearranges material, although the general thread of the story is followed.
At the same time George Munro in New York published an anonymous translation in a newspaper format as #43 of his Seaside Library books. This is the only literal translation containing all the dialogue and scientific discussions. Unfortunately the translation stops after Part II Chapter 10, and continues with the Frewer translation.
The same year a still different translation by Edward Roth was published in Philadelphia by Claxton, Remsen, and Heffelfinger in two parts. Part I (October, 1877) was entitled To the Sun and Part II (May, 1878) Off on a Comet. This was reprinted in 1895 by David McKay.
Occasional reprints of these books were published around 1900 by Norman L. Munro, F.M. Lupton, Street&Smith, Hurst and Co., and Federal Book Co.
In 1911, Vincent Parke and Company published a shortened version of the Frewer translation, omitting Part II, Chapter 3. Parke used the title Off on a Comet, and since that time the book has usually been referred to with that title instead of the correct one, Hector Servadac.
In 1960 Dover (New York) re-published the Roth translations, unabridged, as Space Novels by Jules Verne, including reproductions of the original engravings from the first French editions. In 1965 the I. O. Evans condensation of the Frewer translation was published in two volumes as Anomalous Phenomena and Homeward Bound by ARCO, UK and Associated Booksellers, US. University Press of the Pacific, Honolulu, re-published the Frewer translation in 2000. In September, 2007, Solaris Books (U.K.) published Off on a Comet as an appendix to Splinter by Adam Roberts; a slightly edited version of the Parke edition.
In October, 2007, Choptank Press published a version of Munro's 1877 Hector Servadac, Travels and Adventures through the Solar System edited by Norman Wolcott, followed (December, 2007) by Hector Servadac: The Missing Ten chapters from the Munro Translation newly translated by Norman Wolcott and Christian Sánchez.
From the beginning Verne had problems with this novel. Originally he intended that Gallia would crash into the earth killing all on board. This may have been the motivation for his ghoulish and rather unfunny joke naming the hero "Servadac" with the mirror of the French word cadavres (="corpses"), predicting all would die on the "return". His publisher Hetzel would not accept this however, given the large juvenile readership in his monthly magazine, and Verne was forced to graft a rather unsatisfying ending onto the story, allowing the inhabitants of Gallia to escape the crash in a balloon.
The first appearance in French was in the serial magazine Magazine d'Éducation et de Récréation, commencing on 1 January 1877 and ending on 15 December 1877. It was in June, 1877 when chapter 18 appeared with the introduction and description of Isac Hakhabut — "He was a man of fifty years, who looked sixty. Small, weakly, with eyes bright and false, a busked nose, a yellowish beard and unkempt hair, large feet, hands long and hooked, he offered the well-known type of the German Jew, recognizable among all. This was the usurer with supple back-bone, flat-hearted, a clipper of coins and a skin-flint. Silver should attract such a being as the magnet attracts iron, and if this Shylock was allowed to pay himself from his debtor, he would certainly sell the flesh at retail. Besides, although a Jew originally, he made himself a Mahometan in Mahometan provinces, when his profit demanded it, and he would have been a pagan to gain more."
This prompted the chief rabbi of Paris, Zadoc Kahn, to write a letter to Hetzel, objecting that this material had no place in a magazine for young people. Hetzel and Verne co-signed a reply indicating they had no intention of offending anyone, and promising to make corrections in the next edition. However Verne left the salvage work to Hetzel, asking Hetzel at the end of the summer, "Have you arranged the affair of the Jews in Servadac?" The principal change was to replace "Jew" with "Isac" throughout, and to add "christian countries" to those where Hakhabut plied his trade. The anti-semitic tone remained however, sales were lower than for other Verne books, and the American reprint houses saw little profit with only a single printing by George Munro in a newspaper format. Even the Hetzel revised version has never been translated into English, as both Victorian translations were made from the magazine version. This has caused some modern reviewers to unfairly criticize the early translators, assuming that they had inserted the anti-semitic material which Verne actually wrote.