posted March 10, 2011, jeb
Astronomy 121
the first course in a three course sequence:
Astronomy 121, The Solar System
Astronomy 122, Birth and Death of Stars
Astronomy 123, Galaxies and the Expanding Universe
You can take these courses in any order.
WEB PAGE:
Course Outline
Exam Schedule
Grading
Mid-term exams (two best of three, each count 30% of grade)
(you only have to take two of three)
Course Project (10%)
Final Exam (counts 30% of grade)
In class unannounced quizzes ()
Quizzes can increase your grade by about two percent
Course Project
Select a project based on your interests and imagination.
Examples:
- written report on a topic of interest
- report of an observational exercise
- poster on a topic
- the design of an astronomical instrument
Printed report of 1000-1300 words (about 4-6 pages), unless other content (such as a poster or model) is submitted,
in which case a shorter report of at least 500 words (about 2 pages) may be submitted, but in all cases, a report is required.
References must be reported.
Written material is to be submitted through SafeAssign on Blackboard
Projects are due, without exception, no later than May 24th.
Some suggested projects are listed on the web page
but you are not constrained by these examples.
Do a project on a topic of interest to you,
but be careful that it is original work, and cites sources.
Successful completion of the final exam and the course project are required to pass the course.
Class attendance is mandatory as the exams will contain material from the lectures as well as the textbook.
Exam, Quiz and Project scores will be posted on the web page
with a Astronomy course ID number assigned to each student.
To get your number, go to this web page
and follow instructions
If you wish to
have a different number used, email Professor Brau with the number.
Professor
Inclement Weather
The university is very unlikely to cancel classes due to
inclement
weather.
Although highly unlikely, extremely dangerous weather conditions could
force the university to close.
If this class is cancelled, a notice will be posted on the top of the
class web page.
Astronomy 121, The Solar System
The Sky
The Planets
Solar System Debris
Asteroids, Comets, Trans-Neptunian Objects and Meteoroids
In addition to the planets and their moons,
the Solar System contains many bits of interplanetary debris, including:
Throughout history,
collisions of these objects with Earth has disrupted life.
- The orbital paths of the planets are
elliptical (not circular) with
the sun at
one focus
- An imaginary line connecting the Sun to any planet sweeps out
equal areas
of the ellipse in equal intervals of time
- The square of the planet's orbital period is proportional to the cube
of its semi-major axis
(see table)
Newton's first law of motion:
Newton's second law of motion:
the acceleration of an object is directly proportional to the applied force
.......and inversely proportional to its mass
in other words, the greater the force acting on the
object,
.......or the smaller the mass of the object,
.......the greater its acceleration
Kepler's Laws follow from
Newton
's Law of Universal Gravitation:
The same force (gravity) that determines the motion of celestial
objects (planets, stars, etc.)
....determines the
motion on the Earth
The equation describing the force is:
or Force is proportional to the product of the masses of
the objects
.... divided by the square of the distance between them
This is an
inverse square law
Planetary motion is determined by The Sun's inward pull of gravity
competing with the planet's tendency to continue moving in a straight line.
Escape velocity: Newton's Law of Universal Gravitation explains the
notion of
escape velocity.
Today most people recognize that Astrology is nothing but an amusing diversion
Basics
