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Period: Jan 1, 1450 to Jan 1, 1550
Mars discovery
Like Venus, Mars is very bright, therefore we have been able to see it with a naked eye from the very beginning. However, we only started calling it a planet in either the 15th or 16th century.
(again, could not find the specific date.) -
Period: Feb 19, 1473 to May 24, 1543
Nicolaus Copernicus
Nicolaus Copernicus devoloped the heliocentric model of the solar system that showed us that the planets revolved around the sun and not earth. -
Jan 1, 1543
Mercury discovered
Mercury, Earth, Mars, and Venus are known as Terrestrial planets. Terrestrial from the Latin word "terra" meaning earth. -
Jan 1, 1550
Earth discovered
In the 16th century, Nicolaus Copernicus presented the "heliocentric model" of the solar system that stated earth was just another planet orbiting the sun.
(I could not find the exact date besides the 16th century so i chose the exact middle of the 16th century.) -
Period: Feb 15, 1564 to
Galileo Galilei
Galileo Galilei supported the idea of Nicolaus Copernicus' heliocentric model of the earth. He believed in the idea that everything revolved around the sun and not earth. -
Period: Dec 27, 1571 to
Johannes Kepler
Johannes Kepler had three major laws-
1. The orbit of each planet is an ellipse- meaning and elongated circle or oval shape.
2. A planet sweeps out equal areas in equal times as it orbits the sun.
3. The time of orbit scales with an oval size such that the period squared is proportional to the semi-major axis lenght cubed. Meaning the size of the orbit is scaled with the size of the planet and the period of time squared is proportional to the length of the axis cubed. -
Venus discovery
We cannot say who "discovered" venus because its has always been there. Galileo is the one who was first to observe venus and that it had a moon, but the planets have been here since the big bang, so it goes back to way before recored history. -
Saturn's Rings and Discovery
Galileo first saw saturns rings, but it was a good enough telescope to properly identify them- he actually thought he was seeing three different planets. Then in 1612, Saturns rings were on the same plane as Earth, so they could not be seen. Then in 1613 they could be seen again. Then is 1655 Christiaan Huygens discovered the rings the that surround Saturn. -
Jupiter discovered
Galileo discovered Jupiter and three of its moons, six nights later, he found another moon.
Jupiter, Saturn, Uranus, and Neptune are known as the Gas Giants. They are called this because they are mostly made up of gases. Because these planets have so much gas, it makes them also have much more mass then the terrestrial planets. Since they have more mass, they have a greater gravitational pull and effect than the terrestrial plants. Their atmosphere is about 75% hydrogen, 24% helium and 1% other. -
Period: to
Isaac Newton
Isaac Newton is the one who discovered that the planets orbit eh sun because of a gravitational pull between them. There is a gravitational pull because of two factors- gravity and inertia. Inertia is the tendency of a moving object to continue in a straight line or a stationary object to remain stationary. He was also the one to buld the reflecting telescope. -
Halley's comet
Edmond Halley calculated that many seen comets have the same orbit and would appear about every 76 years. The comet was named "Halley's comet" after his prediction came true. Comets can be thought as "dirty snowballs" that are about he size of Earth mountain. Comets are chunks of ice and dust whose orbits are long, narrow ellipses. Few comets pass near earth because of their orbits. When a comet gets close to the sun, the ice turns to gas, releasing dust. That forms an outer layer caled the coma -
Uranus Discovered
Uranus was discovered by William Herschel. It is the third biggest of the gas giants- it has a diameter of 51,200 km -
Ceres discovered
Ceres was the first asteroid to ever be discovered. Asteroids are made up of rock and metal, as opposed to a comet which is made up of rock, ice and dust. Also, a meteoroid orbits the sun while a comet doesn't. Between 1801 and 1807, astronomers discovered four small objects between Jupiter and Mars. They found 300 more over the next 80 years. There are so many of them, and they are so small, that we cannot call them planets. The stretch between Jupiter and Mars is called the asteroid belt. -
Neptune discovered
Neptune is the only planet that has visible clouds. It was found when astronomers noticed that Uranus was not quite following the orbit they had thought. Neptune is 30 times Earth's distance from the sun. So far, we have discovered 8 mooons around Neptune. -
Hoba
Hoba is the biggest meteor to ever be discovered. Hoba weighs 66 tons. The difference between a meteor, a comet, and an asteroid is that a meteor orbits the sun.
A meteoroid is a chunk of rock or dust in space. They usually come from comets or asteroids. When a meteoroid enters our atmosphere, friction burns it up and causes it to produce a streak of light- then we call it a meteor. If it is large enough, and doesn't burn out before it hits earth's surface, we call ite a meteorite. -
Pluto discovered
Pluto was discovered by Clyde Tombaugh in 1930 while he was searching for an object that might be affecting neptune's orbit. Pluto has a single moon. It is neither a gas giant, or a terrestrial planet. Pluto is a dwarf planet because it can be found with the gas giants but is smaller then terrestrial planets.