Astronomers intro ppt

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A Long Time

Ago In A

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Astronomy



Astronomy –

study of the

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Early Astronomy



Ancient civilizations used Astronomy to

develop ways of keeping time. They

created

calendars

by looking at the

movement of bodies in our solar system.

Mayan’s used the cycles of the Sun, Moon, and Venus to make their calendar.

The Chinese made their calendars based on the moon’s phases and

positions in the sky. The Chinese New Year can be in late January or early

February depending on the cycle of the moon. Friday, Jan. 31st is the Chinese New

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Early Astronomy

Modern Calendar -

Today’s calendar was first made

by the Romans and since then has gone through

changes to make it more accurate. The calendar we

use now is called the

Gregorian Calendar

. The

average year is in our calendar is 365.242 days.

The .242 is how we get

leap years

. How often does a

leap year occur?

Year- time it takes Earth to go around Sun

Month- time it takes Moon to go around Earth

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Early Astronomers

Claudius Ptolemy (168 AD Egypt) – Believed that the Earth was the center of the

universe and all other things revolved around the Earth.

Nicolaus Copernicus (1473-1543)

–

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Early Astronomers

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

Galileo Galilei (1564-1642)–

_First

person to use a telescope, and showed

that the planets are like Earth with

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

Isaac Newton (1643-1727) –

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Early Astronomers



Edwin Hubble (1889-1953)-

discovered

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

Hubble Space Telescope-

launched into

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Earth In Space

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Earth on the Move



Earth’s Rotation

_–

_{The Earth spins on}

its axis to the east causing night and

day. One rotation takes 24 hours.

Sun rises in

the East and

the Sun sets in

the West

The Earth spins at a

speed of 1,040 mi/hr

at

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Earth on the Move



Revolution –

_{The movement of the Earth}

around the Sun. The path is an elliptical.



Elliptical

–

_{A stretched out circle}

_{like an oval.}

The Earth travels around the Sun in about 365.242 days. It is moving at a rate of ~66,626 mi/hr. The average

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Earth’s Tilt



The Earth's axis is tipped at about 23.5°

from its vertical.

This tilt is what

causes the

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THE TILT OF THE EARTH

CAUSES SEASONS.

You can see in the picture that in the Summer, in the

Northern Hemisphere, we are tipped towards the Sun. In the

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Insolation = Sun’s Intensity

In the winter the angle at which sunlight hits the Earth is small making the rays spread out over a larger area making it less intense.

In the summer the angle is greater and the sunlight is more focused and intense when it hits the

Earth causing more heating.

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Did you know?



In the summer in parts of Alaska the sun

never sets. The down side is that during

the winter there are months where the sun

never rises.

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The Moon



Satellites –

natural or artificial bodies that

revolve around large bodies like planets.

Natural satellites are known as

moons.



Luna –

name given to the Earth’s moon.

Moon Stats

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Did you know?

The rate of rotation is 1

complete rotation every 27

days and 8 hours.

The rate of revolution (time to

go around the Earth) also

takes 27 days and 8 hours.

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Features of the Moon



The dark spots

on the moon are

huge craters from

meteors that

have hit the

moon. The moon

has no wind to

flatten the

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How The Moon Was Made

One of the leading ideas of how the moon was made is that in the early

stages of Earth when it was still very hot and in liquid form Earth was hit by a meteor about the size of Mars and broke a big chunk of the Earth off that then began to orbit the Earth. The Moon’s rocky composition is very similar to that of the Earth’s

mantle

which is one of the

reasons this idea was

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Earth and Its Moon

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The Moon and Tides

 The Moon’s gravity pulls on our oceans creating

Tides.

 Tides happen twice a day one side is near the Moon

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Moon Phases



Phases –

Different appearances of the moon

due to its changing position. The moon

changes based on where it is positioned

compared to the Earth and the Sun. The

moon shines bright because it is reflecting

the Sun’s rays.

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Eclipses



Eclipse

–

Is when the shadow of a celestial

body falls on another.

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Eclipses



Lunar Eclipse –

The shadow of the

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Our “Sun:” Our very own star



Contains 99% of our Solar System’s mass



Made of hydrogen and helium

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Our Sun

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Our Sun



Sunspots- cooler, dark spots of

photosphere. Scientists believe that

sunspots may affect Earth’s climate.

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Nuclear Fusion

