1. What process creates energy in the Sun?
2. Why does the Suns size remain stable?
3. How did the Sun become hot enough for fusion in the first place?
4. What do we mean by the surface of the Sun?
The Road to a Sun-Centered
- Almagest published ~150
- Published in 1544
Tycho Brahe (1546-1601)
- Never published
Johannes Kepler (1571-1630)
- Published his Laws of Motion starting in
1) What does the light and dark stuff tell us about the Moon?
a. The moon is geologically active; recent volcanic activity
2) Having more craters means what?
a. More craters = older
3) How does rice paddies, domestication of livestock, and clearing forest
1. What was the solar nebula?
a. Gaseous cloud from which, in the so-called nebular hypothesis of the origin of the solar system, the Sun
and planets formed by condensation
2. What was it made of?
a. Gasses and dust particles
3. How did gravitational coll
a. Pompeii & Herculaneum
i. Buried in a AD 79 eruption of Mt. Vesuvius.
ii. 18th century print of the excavation o Herculaneum gives you a sense of how
deeply these cities were buried.
iii. This was an explosive Plinian eruption
How Old is the Solar System?
Oldest thing in the solar system
A 4.6 billion-year old
piece of the Allende
How do we know? Radiometric Dating
Elements have isotopes which
are unstable i.e. radioactive.
Take Potassium0.011% of all
Potassium is K
Introduction to Astronomy
The Essential Cosmic Perspective, by
Included with your textbook should be an
access package for MasteringAstronomy
Dr. Dan Britt
Office is PSB 442
Office hours are
T Th 9
Why do they launch
What makes a
good location for
You live on a sphere.
And that sphere is
A day is (duhhh) one
At the equator that
means 40,053 km of
motion every day
(thats 1,683 km/hr or
The Life and Death of Stars
1) Pressure & Gravity
a) Stars struggle to keep a balance between pressure and gravity
2) Life as a Low Mass Star
a) Main Sequence: H fuses to He
b) Red giant: He fuses to He in shell around He core
c) Helium Core Burning
What is light?
Light is an
Photons: pieces of light,
each with precise
Light as a Wave
For any wave (say, in the ocean) its
s = f (frequency)
But the speed of ligh