Alaska became the 49th State to join the United States of America.
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The cryptocurrency 'Bitcoin' was created, providing a new digital currency.
The Mars Polar Lander was launched.
A woman in Rome became the first person to receive a bionic hand that can sense touch.
China's Chang'e-4 became the first spacecraft to successfully land on the far side of the Moon.
Workers began construction on the Brooklyn Bridge in New York.
