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Albert Einstein publishes theory of relativity
The theory stated that "the laws of physics are the same for all non-accelerating observers, and that the speed of light in a vacuum was independent of the motion of all observers." -
Clyde Tombaugh discovers Pluto
He discovered Pluto by comparing photo plates of the same region across the sky; Pluto moved across the region. -
Mariner 4 flies past Mars and sends back first picutres of Mars in history
The Mariner 4 images helped scientists to better understand the environment of Mars, and was the final evidence needed in disproving the canals theory. -
Neil Armstrong and Buzz Aldrin land on the moon
The historic moon landing was made on the Apollo 11. Neil Armstrong said when he touched down, "one small step for man, one giant leap for mankind." -
Last Apollo mission to the Moon-Apollo 17
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Space Shuttle Challenger crashes
The Callenger shuttle was intended to be a test artile for the shuttle program. It crashed on its tenth voyage, and its failure saddened the entire nation. -
Hubble Space Telescope launched
The Hubble Space Telescope was launched into orbit around Earth to take pictures of star systems, galaxies, and planets millions of miles away in high definition. In 2015, it celebrated its 25th anniversary. -
James Webb Space Telescope construction begins
The James Webb Space Telescope, the Hubble's improved predecessor, will launch from the Ariane 5 rocket in October 2018. It will be "the premier observatory of the next decade."