Download 1.2 Space

Discovery Through Technology
Astronomer’s Tools:
Our understanding of space has progressed due to the improvement of
the tools available to observe, record and measure and analyze what we
see.
Sundials:
Sundials have been used to measure the passage of time for more than
7000 years.
Telescopes
Telescopes were invented in the late 16th century and they revealed
exciting details about Earth’s closest planetary neighbors. They also
showed the existence of other neighbors in our solar system.
Radio Telescopes and the Hubble Telescope
Today we have super-powerful optical and radio telescopes operating
from the Earth, we have satellites orbiting the earth and telescopes
operating from space.
These technologies have shown us the immensity of objects in space,
and distances across the universe.
Our sun is only an average star, in a small corner of an average galaxy
one among billions of other galaxies.
Measuring distances in space:
1. Astronomical Units- AU measures local distances inside our solar system
AU= distance from center of earth to the center of the sun
1 Astronomical Unit = 149 598 000 kilometers
2. Light-years- Vast distances beyond the solar system are measured
using light years. Light years measure the distance that light travels in
one year. Light travels at a speed of 300 000km/s or 9.5 trillion km per
year.
1 light year = 9.4605284 × 1015 meters 9460528400000000m
or
9460528400000km
Looking into the Past:
When you look at an object in space, you see it as it was at an earlier
time because it takes time for the light from the object to travel to the
Earth across the space. Here are some examples of how long it takes
you to see the light from the following objects in space:
Moon- one second
Sun- 8 minutes
Pluto- 5 hours
Stars- 25 000 years
Today’s telescopes can collect light from distant galaxies. For example
the Hubble Telescope views images from 12 billion years ago!
Activity:
We are going to chart out how far things are away from us in
the solar system.
Planet
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Steps from the sun
less than 0.4
0.75
1
1.5
5
9.5
19
30
39.5
Discovery through Technology Review:
Use pages 378- 382 of Science in Action 9 to answer the following questions:
1. What are three instruments used throughout history to observe the motion of the planet and the stars? Explain how
each one works.
2. What term is used to describe the distance between the earth and the sun?
3. How far does light travel in one second? one hour? 6 months?
4. Why was it important to explorers crossing the oceans to find new lands to use dependable navigation instruments?