Lectures+13+-+18

**__Lecture #13: "Meteors, Meteoroids, Meteorites, and Asteroids"__**

 * Meteors are flashes of light as meteoroids (small space rock) are heated to incandescence by friction with the atmosphere. If a meteoroid arrives on the planet, intact, it changes classification and becomes a meteorite.
 * Fireball or bolides as really bright meteors that result from large meteoroids.
 * Iron and stony-iron meteorites are pieces of differentiated asteroids (core and core-mantle boundary respectively) that were broken apart by previous collisions. Stony meteorites (the most common) are either form the upper mantle/crust of differentiated asteroid, or unaltered space rock (ie. carbonaceous chondrites)
 * Shergottites are Martian meteorites.
 * Asteroids are large space rocks (observable from the Earth, with the aid of telescopes). The are many of them orbiting the Sun, between the orbits of Jupiter and Mars, in the asteroid belt. They are most often "potato shaped," and are cratered. Ceres is the largest asteroid.
 * Asteroid families, like the Floras, are believed to originate from a parent body that was broken apart.
 * Asteroid classes, like the Atens, Amors, Apollos and Atiras are grouped according to their orbital parameters.


 * __Weblinks__: **
 * Scott Manley's video of asteroid discovery that I showed in class.
 * Near Earth Objects (NEOs) as told by NASA.
 * Meteorite studies are fascination and tell us about the solar nebula.
 * The IAU's Minor Planet Center lists all the known NEO, comets, other "minor planets" and small irregular moons of the major planets that have been discovered to date. A neat website to visit!

__Lecture #14: "The Sun"__

 * The core of the Sun is the region where thermonuclear fusion (proton-proton fusion) converts mass to pure energy.
 * This energy is transferred out of the Sun and is emitted by the photosphere (which has sun spots and granulation).
 * The pink chromosphere is above the photosphere, and is fainter, and so is "invisible" on the Earth except during a total solar eclipse. Filaments and spicules/prominences are features of the chromosphere.
 * The corona is the outermost atmospheric layer of the Sun, and it emits charged particles (protons and electrons) as the solar wind. Interaction of there solar wind particles and planetary magnetic fields cause the aurorae.
 * Helioseismology is one method that astronomers use to study the interior of the Sun.


 * __Weblink____s__: **
 * The Sun today: spaceweather.com
 * Convection, as seen in the photosphere.
 * "The Sun is a Mass of Incandescent" A very folksy, 1950s song...one that will stick in your brain.
 * Wikipedia's pages on the Sun Again, more then you'll ever need to know, but if you have a Sun question, likely the answer is here!
 * An excellent, in depth introduction to The Sun from the Astrophysics Group at the Imperial College of London.
 * The Sun from NinePlanets.org (a bit out of date, that website, isn't it?!)
 * The Sun from AstronomyToday.com
 * The Sun from UniverseToday.com
 * Thermonuclear Fusion, the Sun's energy source, as explained by the folks at the University of Oregon.
 * Thermonuclear Fusion, thermo (hot), nuclear (not "nucular") & fusion (joining) see these atoms join!

__Lecture #15: "Jupiter, a model Jovian Planet"__

 * Jupiter's core is small, hot and dense.
 * It's mantle is liquid metallic hydrogen, which is an electrically conducting fluid, and allows for the dynamo effect that produces a strong magnetic field.
 * Jupiter has lovely colours in the clouds, possibly caused by phosphorus compounds.
 * The rings of Jupiter and virtually invisible from the Earth.
 * The Galilean moons are visible from Earth though. Io has volcanos, Europa has an icy crust with a liquid ocean beneath, Ganymede is the largest moon in the solar system and has its own magnetic field and Callisto has one of the oldest surfaces in the entire solar system.
 * __Weblink____s__: **
 * NASA has great pages on all the planets and moons: Jupiter is linked here, as are its 67 moons
 * Of course, wikipedia has a decent Jupiter page too.
 * Europa is the Galilean moon to watch though...life or no life? Only time (and expensive explorations) will tell!
 * Ganymede is the largest moon of Jupiter though...one that has its own magnetic field!
 * Io and Callisto are the last two of the Galilean moons.

__Lecture #16: "Saturn"__

 * Saturn's core, mantle and atmosphere are similar to Jupiter's, though diminished in size/scale/colouration.
 * The rings are many water ice chunks orbiting the planet.
 * The moons we focused on were Titan, Enceladus, Iapetus and Mimas.
 * __Weblink____s__: **
 * NASA's Saturn page is great. You can learn all about its fabulous rings, and 62 moons (including those "provisional ones") from various websites: wikipedia, the Cassini Mission's pages, space.com & National Geographic.
 * The more interesting moons of Saturn are Titan (the largest) Iapetus (with the greatest discrepancy of albedo), Enceladus (showing ice volcanism) and Mimas (the "death star" moon).

__Lecture #17: "Uranus &__ __Neptune"__

 * Both Uranus and Neptune are considered, "ice giants" since as far from the Sun as they are, they are mostly frozen.
 * Both has magnetic fields that are offset from the centre of the planet and tipped with respect to the rotational axis.
 * Uranus rotational axis is almost perpendicular to the ecliptic, and there is no scientific consensus as to the reason for this, as not only is the planet, "tipped" but its rings, and many of its moons have orbital paths around its equator.
 * __Weblink____s__: **
 * __Uranus__:
 * The web, including NASA, has all sorts of pages on Uranus and information about its 27 moons ( Titania included) as well as details about its odd magnetic field (including images ).
 * __Neptune__:
 * Ah Neptune, that last, lonely planet. It's about 30 A.U. from the Sun, where it's really cold and dark.
 * Neptune has 13 known moons, including Triton (ice volcanism) and Nereid (very elliptical orbit).