Aristotle Aristotle lived lived about about 2,300 2,300 years years

ago. He ago. He came up came up with this with this model of model of the solar the solar system. system.

About 500 years ago, a man named Copernicus came up with this new model of the solar system. What do you notice about it?

Take a look and compare – Take a look and compare – what do you notice?what do you notice?

Ancient people liked the idea that the Ancient people liked the idea that the Earth was at the center of the solar Earth was at the center of the solar system. They also thought that the system. They also thought that the orbits of the planets were perfect circles. orbits of the planets were perfect circles. (They aren’t.)(They aren’t.)

But when people made observations, But when people made observations, some things didn’t make sense. They some things didn’t make sense. They often tried to make their theories fit often tried to make their theories fit what they wanted to believe. what they wanted to believe.

The Earth tilts in the same direction The Earth tilts in the same direction no matter where it is compared to no matter where it is compared to the sun.the sun.

The Vernal Equinox occurs today, at 1:36 The Vernal Equinox occurs today, at 1:36 in the afternoon.in the afternoon.

What does that mean?What does that mean?

tt It is usually It is usually

warmer in the warmer in the middle middle latitudes – latitudes – near the near the equator.equator.

This model This model shows part of shows part of the reason.the reason.

Here’s Here’s another another reason that reason that it’s warmer it’s warmer near the near the equator.equator.

The energy from the sun has to go through a larger layer of the atmosphere.

uuThe Phases of The Phases of

the Moonthe Moon NewNew Waxing crescentWaxing crescent First quarterFirst quarter Waxing gibbousWaxing gibbous Full Full Waning gibbousWaning gibbous Last quarterLast quarter Waning crescentWaning crescent

waxing = growing waxing = growing waning = shrinking waning = shrinking

gibbous = “humpbacked”gibbous = “humpbacked”(bigger than half)(bigger than half)

Full moon rises at sunset & sets at sunrise

New moon rises & sets with the Sun

1st quarter rises at noon

3rd quarter rises at midnight

If you’re on the moon…If you’re on the moon…

……it’s the it’s the Earth that Earth that appears to appears to have have phases!phases!

Distances are not to scale, and we have idealized the Distances are not to scale, and we have idealized the illustration by fixing the Earth in space relative to the Sun. illustration by fixing the Earth in space relative to the Sun. In reality, the Earth will be in motion around its orbit as In reality, the Earth will be in motion around its orbit as

the Moon moves around the Earth.the Moon moves around the Earth.

                                                                             

http://csep10.phys.utk.edu/astr161/lect/time/lunar_anim.html

Lunar EclipseLunar Eclipse

A lunar eclipse occurs when the moon passes through the shadow of the earth.

A lunar eclipse can last up to an hour and a half.

During a lunar eclipse the moon may turn a reddish color.

It is not dangerous at all to look at a lunar eclipse because the moon does not make its own light.

Animation by Stephen Gray using photos © James Funkhouser.

The world's first artificial satellite was The world's first artificial satellite was about the size of a basketball, weighed about the size of a basketball, weighed

only 183 pounds, and took about 98 only 183 pounds, and took about 98 minutes to orbit the Earth on its elliptical minutes to orbit the Earth on its elliptical

path.path.

SputnikHistory changed on History changed on October 4, 1957, October 4, 1957, when the Soviet Union when the Soviet Union successfully launched successfully launched Sputnik I.Sputnik I.

A month later, Sputnik II was A month later, Sputnik II was launched, carrying a much launched, carrying a much heavier payload, including a heavier payload, including a dog named Laika.dog named Laika.

The Sputnik launch also led The Sputnik launch also led directly to the creation of directly to the creation of National Aeronautics and National Aeronautics and Space Administration.Space Administration.

In 1961, President John F. In 1961, President John F. Kennedy gave a speech. He Kennedy gave a speech. He

said that the U.S. should work said that the U.S. should work quickly and meet a goal. The quickly and meet a goal. The goal was to send people to goal was to send people to

the Moon and back. the Moon and back.

The U.S. did meet the goal. The U.S. did meet the goal. And it only took eight years. And it only took eight years.

One day in July, Apollo 11 One day in July, Apollo 11 launched towards the Moon. launched towards the Moon. It had three astronauts on it. It had three astronauts on it. They were Neil Armstrong, They were Neil Armstrong,

Edwin (Buzz) Aldrin and Edwin (Buzz) Aldrin and Michael Collins.Michael Collins.

On July 20, On July 20, 1969, Neil 1969, Neil Armstrong Armstrong put his left put his left foot on the foot on the rocky rocky Moon. Moon.

It was the It was the first human first human footprint on footprint on the Moon. the Moon. They had They had taken TV taken TV cameras cameras with them. with them.

The Lunar LanderThe Lunar Lander

That’s one small step…That’s one small step…

The diameter of the sun is The diameter of the sun is about 100 times larger than about 100 times larger than

the Earth.the Earth.

The sun is big, but the largest The sun is big, but the largest stars are 700 times larger than stars are 700 times larger than

our sun.our sun.

Solar EclipseSolar Eclipse

It is dangerous to look at a solar eclipse directly, even if you have It is dangerous to look at a solar eclipse directly, even if you have sun glasses or smoked glass. It is better to view solar eclipses sun glasses or smoked glass. It is better to view solar eclipses through a pin hole projector.through a pin hole projector.

A Solar Eclipse occurs A Solar Eclipse occurs when the moon goes in when the moon goes in front of the sun and front of the sun and blocks most of the sun's blocks most of the sun's light from the earth. light from the earth.

During a total eclipse During a total eclipse all you can see from all you can see from earth is a ring of light earth is a ring of light around the moon which around the moon which is part of the sun the is part of the sun the moon did not cover.moon did not cover.

Solar EclipseSolar Eclipse

Diagram c/o Wikimedia Commons