history of - What is the earliest work considered to be Science Fiction?

I have been reading a lot of Jules Verne's work written in the 1800's. Very clearly science fiction. Mary Shelley's Frankenstein (1818) has some serious science in it also.

What is the earliest work that is recognized as being science fiction?

Answer

As a fan of history and astronomy I had learned that Johannes Kepler wrote what was widely accepted as the 1st Science Fiction story.

Somnium (Latin for "The Dream") was written in 1608, in Latin, by Johannes Kepler. The narrative would not be published until 1634 by Kepler's son. It is the story of an Icelandic boy who learns of an island named Levania (or The Moon) from a daemon (demon). Still Somnium presents a detailed an imaginative description of how the Earth might look when viewed from the Moon, and is considered the first serious scientific treatise on lunar astronomy. Carl Sagan and Isaac Asimov have referred to it as the first work of science fiction.

Though when I searched the internet I found that some contention exists as to what could be the 1st SF tale.

Lucian's True History in the 2nd century, some of the Arabian Nights tales, The Tale of the Bamboo Cutter in the 10th century and Ibn al-Nafis' Theologus Autodidactus in the 13th century all have some elements of SF in them.

While in Billion Year Spree: The True History of Science Fiction Brian Aldiss argues that Mary Shelley's Frankenstein (1818) was the first work of science fiction, there's also the 1666 Blazing World, written by Margaret Cavendish and the 1726's Gulliver's Travels by Jonathan Swift which have claims to that title.

Still... many of those stories in the above works are presented as fantasy or have a decidedly "mysterious" aspect to them, for instance Dr. Frankenstein's methods for building his creature. We are not given specifics, indeed Frankenstein seemed to be feverish -even possessed- while he was building his abomination.

It's not until writers like H. G. Wells and Jules Verne arrive on the scene that what most recognize as Science Fiction emerges in stories presenting themselves as almost believable and extrapolated from trends new technologies made possible while laden with social satire.

To that end something like the 1864 Adventures of Captain Hatteras by Vern or even Wells' 1888 Chronic Argonauts might be considered the 1st SF stories in the more popularized context. Despite all that, it wouldn't be until the 1930's that the Golden Age of Science Fiction would begin.