1. 1.2 – Discovery Through Technology “Human understanding of both Earth and space has changed over time”
The above illustration shows accurately the size of the planets in relation to each other. Is there something about this image that is inaccurate?
Answer = the relative distance between them. To show the distance accurately I would need a slide approximately 40 metres wide in order to fit all of the planet orbits including Pluto.
Username: SESscience Password: student
Username: LA05 Password 1369

2. 1.2 – Discovery Through Technology
Our understanding of space and Earth’s place in it has progressed, thanks to the improvement of the tools available to observe, record, measure, and analyze what we see.
Today we will examine the following area of space exploration:
1. The Astronomer’s Tools
2. The Immensity of Distance and Time in Space
Mars appear red due to the rusted iron element found in its soil.

3. Merkhet Sundials Quadrant Astronomer' Tools Astrolabe Cross-Staff
Ancient Egyptians
Chart astronomical positions
Predict movement of stars
Sundials
7000 years ago
Passage of time
Quadrant
2nd century AD - Egyptians
Measures star height above
horizon
Astronomer'
Tools
Astrolabe
Arabian Astronomers
Made accurate charts of
Star positions
With technological innovation, astronomers make new discoveries and gain more knowledge about what they are seeing.
Cross-Staff
14th Century
Levi ben Gurson
Measure angle between
Moon and any other star

4. 1.2 - Who invented the Telescope?
Galileo was not the inventor, he was user!
In 1608, Dutch eyeglass maker, Hans Lippershey offered a new device to the government for military use.
This new device made use of two glass lenses in a tube to magnify distant objects. He may not have invented the telescope, but Hans Lippershey has been credited with its invention.
He, at least, received the patent for it.
Why do people think of Galileo Galilei as the inventor of the telescope?
As soon as he heard about the wonderous device coming out of the Netherlands, Galileo Galilei was fascinated. He began constructing telescopes, himself, before ever seeing one in person.
By 1609, he was ready for the next inevitable step. He began using telescopes to observe the heavens, becoming the first astronomer to do so.
While Galileo Galilei did not invent the telescope, he made great improvements in the technology.

5. 1.2 - The Telescope Invented in the late 16th Century 1500 – 1600
It revolutionized astronomy.
Revealed details about Earth’s closest neighbours.
Started to understand the scope and size of the objects in the universe.
Today powerful radio telescopes have helped us learn that our massive Sun in only an average sized star lying in a small corner of an average galaxy that is one among billions of other galaxies.
Andromeda Galaxy

6. 1.2 – The Immensity of Distance and Time in Space
There are 2 units use by astronomers to measure distances in outer space:
1. Astronomical Unit (AU)
2. Light-year

7. 1.2 – Astronomical Unit (AU)
The astronomical unit is used for measuring 'local' distances in the solar system.
It is equal to the distance from the center of the Sun to the center of the Earth
approximately 149,599,000 kms.

8. 1.2 – Light-years
A light year is equal to the distance light travels in 1 year
approximately 9.5 trillion km/year
It is used for longer distances - to stars and galaxies.
The distance to our nearest star other than our Sun, Proxima Centauri is a little over 4 light years.
A Parsec
A parsec is a basic unit of length for measuring distances to stars and galaxies,.
equal to 206,265 times the distance from the earth to the sun, or 3.26 light-years
The nearest star, Proxima Centauri is about 1.31 parsecs from the Earth.
The light captured by this photograph was sent outward 4 years before the picture was taken.

9. 1.2 – InfoBit – Big, Bigger, Best
Earth is 1/1000 the volume of Jupiter.
Jupiter is about 1/1000 the volume of the Sun.
The Sun is about 1/300-millionth the volume of Betelgeuse (BET-el-jooz).
Betelgeuse As a massive red supergiant, it is nearing the end of its life and will soon become a supernova.

10. 1.2 Looking into the Past
When you view an object in the sky you are seeing it as it was in the past.
It has taken the light a very long time to reach the Earth.
Light from the Sun takes about 5 minutes to reach the Earth,
whereas light from Pluto takes about 5 hours.
Light from the stars in the center of the universe take about 25,000 years to reach the Earth.
The Hubble telescope is capturing light from 12 billion years ago.

11. Homework – Check & Reflect page 383 Questions 1-7