Introduction to Planetary Science
Introduction to Planetary Science
Introduction to Planetary Science
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the urge <strong>to</strong> explore 3<br />
deliberating for four years, the Commission<br />
declared that Columbus’ proposal was nonsense.<br />
However, the defeat of the Moors by the Spanish<br />
armies in the battle of Granada in 1492 caused the<br />
Queen <strong>to</strong> reconsider. Columbus was recalled <strong>to</strong><br />
the Spanish court and his proposal was approved<br />
on April 17 of 1492. Six months later, on Oc<strong>to</strong>ber<br />
12, Columbus sighted land after sailing west<br />
across the Atlantic Ocean six years before Vasco<br />
da Gama reached India.<br />
Chris<strong>to</strong>pher Columbus had, in effect, rediscovered<br />
North America which had been<br />
populated thousands of years earlier by people<br />
from Siberia and which had also been visited<br />
by Vikings led by Leif Eriksson, son of Erik<br />
the Red, who had established a settlement in<br />
Greenland in 986 AD. In fact, all of the continents<br />
(except Antarctica) and most of the large<br />
islands contained human populations in the 15th<br />
century when the Portuguese began their quest<br />
<strong>to</strong> find a way <strong>to</strong> India, China, and the islands in<br />
the Molucca Sea of Indonesia.<br />
In spite of the discoveries Chris<strong>to</strong>pher<br />
Columbus had made, he had not actually reached<br />
China or the Moluccas. Therefore, Emperor<br />
Charles V of Spain authorized the Portuguese<br />
nobleman Ferdinand Magellan <strong>to</strong> reach the<br />
Moluccas by sailing around the southern end<br />
of the landmass that Columbus had discovered.<br />
A small fleet of five ships sailed on September<br />
20, 1519, with 200 people on board. One year<br />
later, on November 28, 1520, the three remaining<br />
ships sailed through a narrow passage (now<br />
known as the Straits of Magellan) and entered<br />
a new ocean on a calm and sunny day. Accordingly,<br />
Magellan and his surviving associates<br />
named it the Pacific Ocean. However, the<br />
voyage across the Pacific Ocean was a nightmare<br />
because of the lack of fresh food and water. Many<br />
crew members died of scurvy and Magellan<br />
himself was killed in a battle with natives in the<br />
Philippines. The 18 survivors completed the first<br />
circumnavigation of the Earth and returned <strong>to</strong><br />
Seville in 1522 AD after three years at sea.<br />
All of the expeditions of the fifteenth <strong>to</strong> the<br />
seventeenth centuries were motivated primarily<br />
by the desire for wealth and power. The exploration<br />
of the Earth that resulted from these<br />
voyages was an unintended byproduct. Not until<br />
the eighteenth century did scientific exploration<br />
become a fac<strong>to</strong>r in motivating the expeditions<br />
organized by England and France. Noteworthy<br />
among the leaders of these extended voyages<br />
of discovery were Captain Louis An<strong>to</strong>ine de<br />
Bougainville of France (1729–1811) and Captain<br />
James Cook of Britain (1728–1779).<br />
Captain de Bougainville had an illustrious<br />
career in the service of France. He first served as<br />
aide-de-camp <strong>to</strong> General Louis-Joseph Montcalm<br />
in Canada during the French and Indian War<br />
(1756–1763) described by Anderson (2005). In<br />
1763, he led an expedition <strong>to</strong> the South Atlantic<br />
Ocean and set up a French colony on the<br />
Falkland Islands. Next, he sailed around the<br />
world between 1766 and 1769 accompanied by<br />
a group of scientists. In 1772, de Bougainville<br />
became the secretary <strong>to</strong> King Louis XV of France<br />
and served as the Commodore of the French<br />
fleet which supported the American Revolution<br />
(1779–1782). After the French Revolution in<br />
1792, he settled on his estate in Normandy. Later,<br />
Napoleon I appointed him <strong>to</strong> be a Sena<strong>to</strong>r, made<br />
him a Count, and a Member of the Legion of<br />
Honor. He died on August 31, 1811, in Paris at<br />
the age of 82.<br />
James Cook learned his craft as a seaman on<br />
wooden sailing ships that hauled cargo along<br />
the North-Sea coast of England. In 1752 he<br />
enlisted in the Royal Navy and participated in<br />
the siege of Louisburg in Nova Scotia during the<br />
Seven-Years War (1756–1763) between Great<br />
Britain and France (Anderson, 2000). He also<br />
helped General Wolfe <strong>to</strong> cross the St. Lawrence<br />
River for an attack on the city of Quebec.<br />
The British army commanded by General Wolfe<br />
scaled the rocky cliff along the northern bank of<br />
the river under cover of darkness and defeated<br />
the French army of General Montcalm on the<br />
Plain of Abraham on September 13, 1759.<br />
In 1768 the Royal Society of England selected<br />
James Cook <strong>to</strong> command the first scientific<br />
expedition <strong>to</strong> the Pacific Ocean. His orders were<br />
<strong>to</strong> transport a group of British scientists led by<br />
Joseph Banks <strong>to</strong> the island of Tahiti in order<br />
<strong>to</strong> observe the transit of Venus across the face<br />
of the Sun on June 3, 1769. Subsequently, he<br />
was ordered <strong>to</strong> sail south <strong>to</strong> explore the socalled<br />
Terra Australis. During this leg of the<br />
expedition Cook discovered and circumnavigated<br />
New Zealand. He then crossed the Tasman Sea<br />
and, on April 19,1770, discovered the east coast<br />
of Australia. On this voyage he mapped not only