The Hubble telescope is named after Edwin Hubble. Galileo built a telescope by himself. He found the four biggest moons of Jupiter and figures out that Venus had phases like the moon, so he figured out the planets revolved around the sun. Telescopes that use just lenses are called refracting telescopes. The ancient Greeks divided a circle into 360 degrees. From the East horizon to the west horizon is 180 degrees-half of a circle. A degree is 60 arc minutes which is, in turn, 60 arc seconds. If an unenchanted telescope has a diameter of 12 inches, the resolution is one arc second. Natural satellites are Venus, the moon, Mercury, Mars, and the moons of Jupiter and Saturn. The first muggle made satellite was launched in 1957 by the Soviet Union. The United States won the race to the moon, but the Soviet Union sent the first woman into space. Her name was Valentina Tereshkova. The United States sent a woman to the moon 20 years later, in 1983. That woman’s name was Sally Ride.Two accidents on USA space shuttles killed 14 astronauts. The program for space shuttles in the USA was shut down. Rovers are vehicles that are left on planets and then they drive around. That’s all for today!