Reading: Chapters 1 of both The New Solar Sytem and of Atmospheres (see syllabus for these required textbooks).
The Planets
note - click on a diagram and you should get a larger version.
Remind yourself of basic planetary facts and characteristics. For those who have not taken any introductory astronomy courses, here is my online class Intro Astro Solar System 101.
We will be reviewing a couple of planetary objects in each class for the next few classes. Here is the first presentation about Pluto (1.3 MB Powerpoint presentation or 330KB .pdf).
Planetary Atmospheres
.1974
Mariner 10 image..
Best
ground-based image
Lots
and lots of interesting questions...
More unknown than known...
After some basic fundamentals of atmospheres we will start with the lesser atmosphere and build up to the gas giants. But then we will concentrate on atmospheric evolution, emphasizing comparison of Earth, Venus and Mars.
Titan: A very special atmosphere - One obvious highlight of this semester is going to be the descent of the Huygens probe into the atmosphere of Titan - part of the Cassini mission to Saturn - which happens on Friday Jan 14th. Here's the main JPL website http://saturn.jpl.nasa.gov/home/index.cfm. In the meantime - Here's the short summary of Titan (powerpoint or .pdf)
Gravity
Force of gravity Fg = GMm/r2 - between M and m separated by r
Accelaration of mass m due to mass M is g=F/m=GM/r2
Acceleration due to gravity at the surface of planet of mass M and radius R is g(planet)= GM/R2
Example 1:
g on Jupiter (at cloud tops ~ where pressure = 1 bar) compared with Earth's surface
g(Jupiter)/g(Earth) = [GMJ/RJ2 ] / [GME/RE2] = MJ/ME x (RJ/RE)< sup>2 = 318 / 112 = 2.6
So, the gravitational acceration on Jupiter is 2.6 times larger than on Earth.
Example 2:
g at top of Mount Everest @ about 8 km ~ 8/6400 =0.00125 RE
g(Everest)/g(sealevel) = (RE/1.00125RE)2 = 0.9975
Velocities
Here is a reminder about orbital velocities and escape speeds, etc.;
