-
Ptolemy theorized that Earth was the center of the universe and that the other planets and the Sun revolved around it. That is called geocentric.
-
Copernicus theorized that the sun was the center of the universe and that Earth revolved around the Sun along with other planets. That is called heliocentric.
-
Galileo used the telescope to observe objects in space including carters and mountains on the moon and sunspots on the sun.
-
Sputnik was the first artificial satelite in space launched by the Russians.
-
The first human to orbit Earth was Russian cosmonaut Yuri Gagarin.
-
Apollo II was the first mission to land people on the moon. To go to the moon NASA built the Saturn V the most powerful rocket.
-
Spirit and Oppurtunity were two Mars robotic explorers. They have been search and collect samples so scientists can learn more about Mars.
-
Aristotle also believed that the universe was geocentric. He theorized that the stars are other suns far away and that our Sun is much larger than Earth, it is just far away.
