Class 5:
Astronomy 101
Celestial Motions
Very Large Array (VLA)
Soccoro, NM
Class 5: Astronomy 101
& Celestial Motions
Class updates:
• Reading: 18.4, 22.1-22.5, 24.1
• Extra credit: Geology Colloquium
- Wed./Thurs./Fri. this week (www.geo.utep.edu  2011 Colloquium link)
• Homework 2 & Midterm1 returned
Today’s topics:
• Where are we in the universe?
• Seasons
• Important people
• Lunar phases
• Tools of Astronomy
• Eclipses
Where are we in the universe?
Planet?
Galaxy?
Supercluster?
Universe?
Star-orbiting system?
Cluster Group?
Our Cosmic Address
A Universal Summary
Stellar
Nurseries
Constellation
Orion
Hubble
Solar System Formation
solar
nebula
Our Solar System
STANDARD MODEL
rocky planets
(Terrestrial)
gas planets
(Jovian)
The Solar System
1 AU: distance from Sun to Earth = 150,000,00 km
Venus
Mars
Asteroid Belt
Jupiter
Mercury
SUN
1 AU
1.5 AU
2 AU
Jupiter, 11x Rearth
3 AU
Uranus, 4.1x Rearth
Saturn, 9.5x Rearth
S
U
N 1 AU
5 AU
4 AU
10 AU
5 AU
Pluto, 0.2x Re
Neptune, 4.0x Rearth
20 AU
30 AU
40 AU
The Solar System
words
YOU SHOULD KNOW:
Mercury
Venus
Earth
Mars
Asteroids
Jupiter
Saturn
Uranus
Neptune
Pluto
How do we know?
Who is responsible?
Early Astronomers
•
500 BC Pythagoras - thought Earth was round
from moon observations
• 350
BC Aristotle - first to suggest that all planets & stars orbited
the Earth (wrong!)
- Earth-Centered model = Geocentric Model
Pythagoras
Aristotle
500
250
0 AD
250
1500
1600
1700
1800
1900
Ptoo bad for Ptolemey
Claudius Ptolemey (100 - 170 A.D.)
Ptolemy geocentric diagram
(Earth at center)
Pythagoras
Aristotle
500
250
Ptolemy
0 AD
250
1500
1600
1700
1800
1900
Crazy (but not really) Copernicus
Nicholas Copernicus (1473-1543)
Copernicus heliocentric diagram
(Sun at center)
Pythagoras
Aristotle
500
250
Ptolemy
0 AD
250
Copernicus
1500
1600
1700
1800
1900
Keeping up with Kepler
Johannes Kepler (1571 - 1630 A.D.)
Kepler’s Laws (3)
Pythagoras
Aristotle
500
250
Ptolemy
0 AD
250
Copernicus
1500
Kepler
1600
1700
1800
1900
Galileo the Great
Galileo Galilei (1564 - 1642 A.D.)
Galileo’s
moon phases
Pythagoras
Aristotle
500
250
Ptolemy
0 AD
250
Copernicus
1500
Galileo
Kepler
1600
1700
1800
1900
How do we know?
Light waves: traveling
energy
infrared image
x-ray image
visible image
Tools of Astronomy: Telescopes
Main functions of optical telescopes
Optical Telescopes
mirror
light in
(more common)
eyepiece
eyepiece
lense
light in
Radio Telescopes
visible
radio
visible
light in
radio
Where should telescopes go?
US light pollution
Mauna Kea, Hawaii
Telescopes and Observatories
(you should visit)
•
Hubble Space
Hubble
SpaceTelescope
Telescope
•
Keck: Mauna
Keck:
MaunaKea,
Kea,Hi
Hi
•
Hale: Palomar
Hale:
PalomarObs.,
Obs.,CA
CA
•
Clark: Lowell
Clark:
LowellObs.,
Obs.,AZ
AZ
•
Shane: Lick
Shane:
LickObs.,
Obs.,CA
CA
•
Kitt Peak
Kitt
PeakObs.,
Obs.,AZ
AZ
•
Aricebo,
Aricebo,Puerto
PuertoRico
Rico
•
Very Large Array (VLA), NM
Rotation & Revolution
rotation
revolution
Reason for Seasons?
23.5°
North Pole
Equator
Equator
Reason for Seasons
Sun
Earth’s
orbit
Earth
Spin axis
(Winter)
NH
SH
(Summer)
Sun
Reason for Seasons
Sun
Earth’s
orbit
Earth
Spin axis
(Summer)
NH
SH
Sun
(Winter)
Northern Hemisphere
Seasons
Seasons, Tropics, & Circles
Seasons Review
Reason for Seasons Movie
Day/Night & the Seasons
•
Why are days are longer in the summer,
shorter in the winter?
Summer sun
path
Winter sun
path
The Phases of the Moon
Times of Moonrise and Moonset
Phase
New
First Quarter
Full
Third Quarter
Moonrise
Dawn
Noon
Sunset
Midnight
Moonset
Sunset
Midnight
Dawn
Noon
Why We Always See the
Same Side of the Moon
Day 7
Day 14
NP
Day 21
Day 1
Eclipses
partial solar eclipse
total solar eclipse
lunar eclipse
Lunar Eclipses
Solar Eclipses
How do they happen?
•
Moon moves in between Sun and Earth, blocks sunlight
•
Only from within the tiny area where the dark umbra
touches the Earth will you see the Sun completely covered
and witness a total eclipse.
•
From anywhere in the grey penumbra, you will see some part
of the sun shining from behind the moon. The penumbra is
the area of partial eclipse.
Solar Eclipses
The Moon is much smaller than the Sun so how can the
Moon block out the Sun?
total
eclipse
partial
eclipse
Solar Eclipse Movie
Movie of solar eclipse taken in India (NASA Goddard Space Flight Center)
Eclipses: Why so Infrequent?
Why isn’t there a solar eclipse & lunar eclipse once
every month?
Sun
Earth’s
orbit
Earth
Moon’s
orbit
Moon