Page 68 - BBC History The Story of Science & Technology - 2017 UK

Heaven & Earth / Galileo

MOON

SHAKER

Over 400 years on from the first lunar
observations by telescope, Christopher Lewis

considers how Galileo Galilei changed our view

of the Moon and the heavens

he first giant leap towards only a small step further to imagine the likewise, the true cause of the Via Lactea
landing on the Moon Moon as another ‘New World’, ripe for [Milky Way], so long searched; and lastly, that
may have been taken exploration and colonisation. the Moon is not spherical, but endued with
over 400 years ago. It was on 13 March 1610 that the English many prominences… And the author
From the summer of ambassador to the Republic of Venice, runneth a fortune to be either exceeding
1609 onwards, telescopic Sir Henry Wotton (1568–1639), dashed off famous or exceeding ridiculous.”
T studies by Galileo Galilei a letter to secretary of state Robert Cecil
and other astronomers helped to shatter (1563–1612), enclosing a slim booklet, Through the looking glass
the dominant medieval belief in the hot off the press: The optical instrument was a telescope.
intrinsic separateness and inaccessibility, “I send herewith unto His Majesty The first clear, public claim to “a new
the literal other-worldliness, of the heavens [James I] the strangest piece of news (as I may invention”, “a certain device by means
and the Moon. justly call it) that he hath ever yet received of which all things at a very large distance
“The surface of the Moon,” claimed from any part of the world; which is the can be seen as if they were nearby, by
Galileo, “is not smooth, uniform, and annexed book (come abroad this very day) of looking through glasses”, was made in the
precisely spherical as a great number of the Mathematical Professor at Padua, who by Dutch Netherlands in September 1608.
philosophers believe it (and the other the help of an optical instrument (which both News of the invention spread rapidly
heavenly bodies) to be, but it is uneven, enlargeth and approximateth [brings closer] throughout Europe and actual working
rough, and full of cavities and prominenc- the object) invented first in Flanders, and examples of the ‘spyglass’ or ‘optic tube’
es, being not unlike the face of the Earth, bettered by himself, hath discovered four new followed not far behind, arriving in Italy
relieved by chains of mountains and planets rolling about the sphere of Jupiter, in the summer of 1609.
deep valleys.” besides many other unknown fixed stars; The “Mathematical Professor at Padua”
The telescope, an instrument that Galileo referred to by Wotton was the 45-year-old
did so much to refine, transformed our well-respected academic Galileo Galilei. He
understanding of the Moon (and of the Galileo wanted to had been improving the telescope design,
heavens in general) even more profoundly and by the end of August 1609 he had
than the Apollo astronauts’ first view prove that the developed a telescope that magnified some
of ‘Earthrise’ from the Moon helped change eight or nine times; by the end of the year he
modern awareness of our fragile Earth. Moon was basically had a good eyeglass of 20x power.
From the moment that Galileo began to The booklet Robert Cecil received was
point his telescope towards the skies, it was like the Earth Galileo’s The Sidereal Messenger (Sidereus

68 The Story of Science & Technology