Transcript Nebular Theory and Big Bang

Nebular Hypothesis Theory
Cornell Notes
Page 41-42
What is a Theory?
A theory is both a goal and a tool of
research
Theories ask the questions that look
beyond the facts and laws of science
Theory statements can be refuted, but not
verified, no matter how strongly we believe
in the truth of a theory. It is always
possible for it to be falsified.
Nebular Hypothesis Theory
The birthplace of our solar system was a
NEBULA
– A nebula is a “fuzzy” patch in the sky, either
light or dark; a cloud of gas and dust
– Our solar system evolved from a swirling
cloud of dust (Nebular Theory)
– Gravity caused the gases and dust to be
drawn together into a denser cloud (rate of
rotation increased)
Nebular Hypothesis Theory cont.
– As a result the cloud collapsed to resemble
a disk. Most of the mass collapsed in the
center
– Matter in the rest of the disk clumped
together to form planetesimals =
protoplanetary bodies
– Hydrogen gas combined or fused to form
helium atoms (nuclear fusion – a source of
energy from the sun!)
The Sun was born!!!
Examples of Nebulas
Eagle Nebula
Examples of Nebulas
Orion Nebula
– Located in the
constellation Orion
One last example
Cats Eye Nebula
Our solar system
Terrestrial planets:
inner part of solar
system
Characteristics: small
and rocky
–
–
–
–
Mercury
Venus
Earth
Mars
Our solar system
Gas giants: larger planets
Characteristics: colder and covered with Hydrogen (gas & liquid)
–
–
–
–
Jupiter
Saturn
Uranus
Neptune
Pluto: no longer considered a planet but still there!!!
Planets (continued)
Rotation is how long it
takes for a point on
planet to spin around
and face the sun
– Length of day
Revolution is how
long it takes a planet
to go around the Sun;
also known as orbit
– Length of year
Other stuff in the solar system
Comets
Asteroids
Meteoroids
Gas
Dust
Satellites
Space “Junk”
Can you think of
anything else?
Planets (con’t)
Comets – Halley’s Comet – 76 yrs 2052
– Mixtures of frozen gases, ice and rocky debris
– Outer solar system
– Looping orbits bring close to the Sun, ice melts thus having
streaming tails
Asteroids
– Dark, rocky bodies that orbit the Sun
Milky Way Galaxy
Swath of light formed
by the glow of billions
of stars
Flat spiral collection
of stars
Largest celestial
feature
Formed 10 billion
years ago
Other Galaxies
Whirlpool Galaxy
Sombrero Galaxy
Andromeda Galaxy
Large Magellanic Cloud
Halley’s Comet http://science.discovery.com/videos/100greatest-discoveries-shorts-halleyscomet.html
Space Junk - http://www.naturalenvironment.com/images/blog/space_junk
_2.jpg