Transcript Chapter 26 ASTRONOMY

Chapter 26
ASTRONOMY
THE SCIENTIFIC STUDY OF SPACE / THE UNIVERSE.
Galactic address
Planet
Star
The Sun
Star System/Galaxy
The Milky Way
Galactic Group
Local Group
Galactic Supercluster
Virgo Supercluster
GALACTIC ADDRESS
Measuring distances in the Universe
• Astronomical Unit (AU) = 150 million km
( = 149,597,870.66 km )
– The average distance from the EARTH to the SUN.
• Light year = 9,460,700,000,000 km
( = 9.4607 x 1012 km )
This is based on the speed of light = 186,000 mi/s
= 300,000,000 m/s
- The distance that light travels in one year.
• Parsec = 3.26 light years = 19 trillion miles.
Astronomical
Distances and Scales
http://htwins.net/scale2/
Units of Distance
• Astronomical Unit – The average distance
from Earth to the sun
~ 150,000,000,000 meters
• Light Year – The distance light travels in 1 year
~ 9,500,000,000,000,000 meters
Powers of 10
0.001 = 1 ÷ 1,000 = 𝟏𝟎−𝟑
0.01 = 1 ÷ 100 = 𝟏𝟎−𝟐
0.1 = 1 ÷ 10 = 𝟏𝟎−𝟏
1 = 𝟏𝟎𝟎
 this also equals 1.0
10 = 𝟏𝟎𝟏
100 = 10 x 10 = 𝟏𝟎𝟐
1000 = 10 x 10 x 10 = 𝟏𝟎𝟑
AND SO ON…
Scientific Notation
• Step 1: Find decimal point (3000 = 3000.0)
• Step 2: Move decimal point to where it is directly
to right of first non-zero digit. Count the number
of spaces the decimal point moves
• Step 3: Write down the new number with x10 on
the end, put the number of spaces the decimal
point moved at the top right corner of the x10
(it is a positive number if point moved left and it
is a negative number if point moved right)
Examples
128,000,000 meters can be changed to:
1.28 x 108 meters
0.000000128 meter can be changed to:
1.28 x 10−7 meter
Looking at distant objects is like looking back in time.
Observing space
• The electromagnetic spectrum represents different
types of energy, each having different wavelengths,
traveling at the speed of light.
Link
Telescopes
REFRACTING
REFLECTING
Optical telescope
Uses lenses to bend light
(refraction)
Optical telescope
Uses a curved mirror (reflection) to
gather and focus light
Problems:
*Focuses different colors of light at
different distances.
*Ability to see distant objects is
based on the size of their objective
lens.
Advantages:
*Can be made larger, can gather more
light, can see more distant/fainter
objects.
*Less distortion
*Eliminates color differences
National Radio Astronomy Observatory
(NRAO)
• Green Bank, West Virginia
Robert C. Byrd Green Bank Telesco
(100 meters in diameter)
Keck Telescopes – 10m
OWL (Overwhelmingly Large Telescope) – 100m
- optical and near-infrared
Only
Proposed!
Gran Telescopio Canarias
Human Space Exploration
National Aeronautics and Space Administration (NASA)
100,000 Stars
Supernova in Messier 82
Ant Nebula
Horsehead Nebula
Comet ISON
Solar Prominence
Uranus
Jupiter’s triple solar eclipse event