Sidereus Nuncius

The more Galileo looked, the more he was convinced of the sun-centred Copernican model of the planets. Galileo wrote a book “Dialogue Concerning the Two Chief World Systems, Ptolemaic and Copernican” and dedicated it to the Pope Urban VIII. But his ideas were considered heretical, and Galileo was called to appear before the inquisition in Rome in 1633. He struck a plea bargain and was sentenced to house arrest, where he continued to work and write until his death in 1642.

Elsewhere in Europe, scientists began improving the telescope. Johannes Kepler studied the optics and designed a telescope with two convex lenses, which made the images appear upside down. Working from Kepler’s writings, Isaac Newton reasoned it was better to make a telescope out of mirrors rather than lenses and built a reflecting telescope in 1668. Centuries later the reflecting telescope would dominate astronomy.

The astronomical telescope becomes an invaluable tool of scientific discovery!

To promote his discoveries to the wider population Galileo published a short book Sidereus Nuncius in Italian and not the Latin language of scholars.

Sidereus Nuncius (usually Sidereal Messenger, also Starry Messenger or Sidereal Message) is a short astronomical treatise (or pamphlet) published by Galileo Galilei on March 13, 1610. It was the first published scientific work based on observations made through a telescope, and it contains the results of Galileo’s early observations of the imperfect and mountainous Moon, the hundreds of stars that were unable to be seen in either the Milky Way or certain constellations with the naked eye, and the Medicean Stars (later Galilean moons) that appeared to be circling Jupiter.

The Latin word nuncius was typically used during this time period to denote messenger; however, it was also (though less frequently) rendered as message. Though the title Sidereus Nuncius is usually translated into English as Sidereal Messenger, many of Galileo’s early drafts of the book and later related writings indicate that the intended purpose of the book was “simply to report the news about recent developments in astronomy, not to pass himself off solemnly as an ambassador from heaven.’ Therefore, the correct English translation of the title is Sidereal Message (or often, Starry Message).

A copy of the original edition is a valuable rare book and as of December 2010 has sold at auction for US$662,500, including premium. What would have been a multi-million dollar copy brought to a rare book dealer in 2005 with the title page signed by Galileo himself and watercolors, also attributed to Galileo, instead of etchings, was at first declared to be genuine by rare book experts and later shown to be a forgery.