Transcript Linking Asteroids and Meteorites through Reflectance

Astronomy 101
The Solar System
Tuesday, Thursday
Tom Burbine
[email protected]
Course
• Course Website:
– http://blogs.umass.edu/astron101-tburbine/
• Textbook:
– Pathways to Astronomy (2nd Edition) by Stephen Schneider
and Thomas Arny.
• You also will need a calculator.
HW #3
• On Spark under Assessments:
• Due Date: February 2, 2010 1:00 PM
Metric System
• 1 kilometer = 1,000 meters
• 1 meter = 100 centimeters
• 1 centimeter = 10 millimeters
Scientific Notation
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10000 = 104
100000000 = 108
10000000000 = 1010
100000000000000000000 = 1020
0.001 = 10-3
0.0000001 = 10-7
How do you write numbers?
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31700000 = 3.17 x 107
2770000 = 2.77 x 106
0.00056 = 5.6 x 10-4
0.0000078 = 7.8 x 10-6
How do you do multiply?
• 106 x 108 = 10(6+8) = 1014
• 10-5 x 103 = 10(-5+3) = 10-2
• (3 x 104 ) x (4 x 105) = 12 x 10(4+5) = 12 x 109
= 1.2 x 1010
How do you divide?
• 108/106 = 10(8-6) = 102
• 10-6/10-4 = 10(-6-(-4)) = 10-2
• (3 x 108)/(4 x 103) = ¾ x 10(8-3) = 0.75 x 105
= 7.5 x 104
How many stars in the Universe
• Say there are 100 billion galaxies
• Each galaxy has 100 billion stars
• So how many stars in the universe
Answer
• Number of stars in universe
• = (100 x 109) x (100 x 109) = 10000 x 1018
= 1 x 1022 = 10,000,000,000,000,000,000,000
• This is about the same number of grains of sand
in every beach in the world
Questions:
• How many of these 1022 stars have planets?
• How many of these planets have life?
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My - Mercury
Very - Venus
Eager - Earth
Mother - Mars
Just - Jupiter
Served - Saturn
Us -Uranus
Nine -Neptune
Pizzas - Pluto
Does anyone play basketball?
Assume
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That the sun is the same size as a basketball
Basketball diameter = 24.4 cm
Sun Diameter = 1.4 x 109 m = 1.4 x 1011 cm
Scale Factor = 1.74 x 10-10
Multiply scale factor by actual diameters of
planets to get their approximate size
Mercury
• Diameter = 4.88 x 106 m
• Multiply by scale factor (1.74 x 10-10)
• Relative Diameter = 8.5 x 10-4 m = 0.85 mm
Venus
• Diameter = 1.21 x 107 m
• Multiply by scale factor (1.74 x 10-10)
• Relative Diameter = 2.1 x 10-3 m = 2.1 mm
Earth
• Diameter = 1.28 x 107 m
• Multiply by scale factor (1.74 x 10-10)
• Relative Diameter = 2.2 x 10-3 m = 2.2 mm
Mars
• Diameter = 6.80 x 106 m
• Multiply by scale factor (1.74 x 10-10)
• Relative Diameter = 1.2 x 10-3 m = 1.2 mm
Jupiter
• Diameter = 1.43 x 108 m
• Multiply by scale factor (1.74 x 10-10)
• Relative Diameter = 2.5 x 10-2 m = 25 mm = 2.5 cm
Saturn
• Diameter = 1.21 x 108 m
• Multiply by scale factor (1.74 x 10-10)
• Relative Diameter = 2.1 x 10-2 m = 21 mm = 2.1 cm
Uranus
• Diameter = 5.18 x 107 m
• Multiply by scale factor (1.74 x 10-10)
• Relative Diameter = 9.0 x 10-3 m = 9 mm
Neptune
• Diameter = 4.95 x 107 m
• Multiply by scale factor (1.74 x 10-10)
• Relative Diameter = 8.5 x 10-3 m = 8.5 mm
Pluto
• Diameter = 2.30 x 106 m
• Multiply by scale factor (1.74 x 10-10)
• Relative Diameter = 4.0 x 10-4 m = 0.4 mm
What if we want to use the same scale factor
to make a model of the solar system?
• What’s the problem?
How far away is Pluto?
• Pluto is 5.9 x 1012 m from Sun on average
• Multiply by scale factor (1.74 x 10-10)
• Relative Distance from Sun = 1027 m = 1.027 km
Seasons
• http://www.learner.org/resources/series28.html
Phases
of the
Moon29.53
day
cycle
http://en.wikipedia.org/wiki/File:Lunar-Phase-Diagram.png
Eclipses
Moon is tilted at an angle of 5 degrees to Earth’s orbit
• http://astronomyonline.org/SolarSystem/LunarEcl
ipse.asp
Color of lunar eclipse
• The Moon does not completely disappear because of the
refraction of sunlight by the Earth’s atmosphere
• If the Earth had no atmosphere, the Moon would be
completely dark during an eclipse.
• The red color arises because sunlight reaching the Moon
must pass through the Earth’s atmosphere, where it is
scattered.
• Shorter wavelengths are more likely to be scattered by the
small particles. By the time the light has passed through
the atmosphere, the longer wavelengths dominate. This
resulting light reflected from the Moon we perceive as red.
Solar eclipse
http://en.wikipedia.org/wiki/Image:Solar_eclips_1999_4_NR.jpg
• Solar eclipses occur approximately every 18 months
• However, they recur (on average) at any given place only
once every 370 years
• Moon's umbra moves eastward at over 1,700 km/hr
• Every year, there are at least two lunar eclipses.
• Can be viewed anywhere on the night side of the Earth
http://home.cogeco.ca/~astrosarnia/Photos/Lunar%20eclipse%20binocular.jpg
Solar eclipse of July 22, 2009
• Lasted a maximum of 6 minutes and 39 seconds
off the coast of Southeast Asia
http://upload.wikimedia.org/wikipedia/commons/f/f2/Solar_eclipse_animate_%282009-Jul-22%29.gif
http://en.wikipedia.org/wiki/File:Solar_eclipse_22_July_2009_taken_by_Lutfar_Rahman_Nirjhar_from_Bangladesh.jpg
Any Questions?