Transcript Document

Origin of the Solar System
Spiral Galaxy
Beta Pictoris
Star Birth, Orion Nebula
Solar Nebula
Formation of the Universe
Origin of the Solar System
Historically there have been two competing
classes of hypotheses for origin of the solar
system.
1. Dualistic or Encounter Hypothesis
Le Clerc (Comte de Buffon) in 1745
T.C. Chamberlain in early 20th century
2. Nebular Hypothesis
Descartes 1644
Immanuel Kant 1755
Laplace 1796
Dualistic Hypothesis
Nebular Hypothesis
Beta Pictoris is a young
star about 20 million
years old that is located
63 light years away.
Beta Pictoris
This false-color image of the disk surrounding Beta Pictoris was
obtained at the European Southern Observatory by blocking
direct starlight and imaging the near-infrared light from the disk.
The Beta Pictoris disk
appears to be a young
planetary system in the
making. This image
supports the standard
model of solar system
birth, which supposes that
planets accrete from a
disk of dust and gas
surrounding a young star.
At the heart of the Orion
Nebula lies a complex of
molecular clouds where
abundant star formation is
occurring today.
The clouds are illuminated by a
flood of ultraviolet light emitted
by four bright stars, collectively
called the Trapezium.
Orion Nebula, giant stellar
nursery ~1600 light years away
More than 150 protoplanetary
disks have been found in this
mosaic of HST images.
At the center of each
proplyd
(protoplanetary disk)
is a T Tauri star.
The disks surrounding
them are two to eight
times the diameter of
our solar system.
Solar Nebula with Bipolar Outflow
Nucleosynthesis
Nucleosynthesis
Our Sun’s fusion only creates He, need red giant for heavier elements.
Chart of the Nuclides
Nucleosynthesis
Elements heavier than Fe created by s- and r-processes in a supernova
Interplanetary Dust Grain
In this scanning
electron microscope
image, all the minerals,
organic compounds,
and amorphous
materials look the
same. However,
isotopic analysis
reveals that some
components of this dust
actually solidified in
interstellar space long
before our Sun and its
planets formed.
In-falling interstellar gas and dust is focused inward
towards the proto-sun.
Chondrules formed from
melted dust grains that
were flash-heated in the
inner solar nebula.
Planetesimal Growth
Proto-planet Formation
Temperature in the Solar Nebula
The Solar System
Terrestrial Planets
Mercury, Venus, Earth, Mars
Terrestrial Planets
Giant Planets
Jupiter, Saturn, Uranus, Neptune
Giant Planets
Habitable Zone in our Solar System
Midterm #1 EPS 365
10
Frequency
8
6
4
2
0
40
50
60
70
Percent Score
Median 64
Mean 64
80
90
100
Midterm #1 EPS 365
Normalized to High Score (88% or 29/33)
Blue Value
10
Frequency
8
B
C
A
6
4
2
0
40
50
60
70
Score
Median 73
Mean 72
80
90
100