The Sidereal Messenger

What it is

This book is an English translation, published in 1880 by Edward Stafford Carlos, of Galileo Galilei's original account of what he saw through his telescope, along with part of the preface to Johannes Kepler's Dioptrics. The scanned copy includes a photograph of one of Galileo's own broken telescope lenses, exhibited at the South Kensington Museum.

Why it matters

Galileo's original observations - mountains on the Moon, the moons of Jupiter, countless new stars - transformed astronomy and supported the Copernican model. This translation, made over two centuries later, shows how later scientists and scholars, including Kepler, worked to understand and spread Galileo's discoveries to new readers.

Look closer

• This is a translation, not Galileo's own words - what might change or be lost when a text is translated long after it was written?
• Why might a 19th-century publisher have included a photograph of Galileo's broken lens?
• What does it suggest about Galileo's reputation that his book was still being translated and read centuries later?