Final Exam

Front 1

More than 700extra-Solar planets have been discovered in the last 15 years. What method was used to discover most of these planets?

Back 1

The doppler method

Front 2

More than 700extra-Solar planets have been discovered in the last 15 years.What other methods are used? What is the Doppler shift?

Back 2

astrometric searches (Indirect), spectroscopic searches (ID), occultation searches (Direct), gravitational micro-lensing searches (D)

-The wavelength of light emitted by a moving object is shifted. This effect is called the doppler shift.

If the object is coming toward you, the light is shifted toward shorter wavelengths, blue shifted.

If the object is going away from you, the light is shifted toward longer wavelengths, red shifted.
The amount of shift is bigger if the emitting object is moving faster

Front 3

What is Kepler and what important results will Kepler potentially produce?

Back 3

The NASA mission Kepler is observing 156,000 nearby stars to search for transits in extra-Solar planetary systems ( a transit of Mercury).

Front 4

What is the simplest way in which to differentiate between Jovian and Terrestrial planets in this sample? What do they tell us about the current state of our understanding of the Solar System and its formation?

Back 4

-Jovian planets are usually 10x bigger than Earth. As we have found planets outside our solar system is that they are close to their star and are Jupiter-size or bigger in a location where terrestrials would usually be. This tells us our understandings of planetary systems may be wrong and only apply to our system.

Front 5

What is the center of mass of a system?

Back 5

In planetary systems, the star is always much more massive than the planets and the center-of-mass is very close to the star.

Front 6

What the dynamical regularities and what are the planetary properties any viable theory for the origin of our Solar System must explain?

Back 6

Dynamical Regularities:
All planetary orbits are roughly in the same plane -- low inclinations

All planetary orbits are roughly circular -- small eccentricities

All planetary orbits are in the same sense -- CounterClockW as viewed from the North

Front 7

What are some minor dynamical regularities any theory for the Solar System must explain?

Back 7

Minor regularities are:
Most planets rotate in the same sense as they orbit

The rotation axes of most planets are roughly perpendicular to the ecliptic

The orbits of the major moons of most planets are in the CounterClockW sense

Front 8

Terrestrials vs. Jovian Planets

Back 8

-Jovian planets are usually 10x the size of Earth- Jupiter is 317x bigger

-Terrestrials 1 A.U. -Jovian 5.2 A.U.

-Terrestrials- silicates, nickel, iron Jovian-Hydrogen, Helium

-Terrestrials- solid atmospheres Jovian- Not solid, but extensive atmospheres

-Terrestrials are smaller and more dense than Jovian planets

-Iron cores- magnetic fields for Terrestrial planets

Jovian planets have stronger magnetic fields, Jupiter is 19,000 stronger than Earth’s due to hydrogen amounts.

Front 9

How does the condensation theory for the origin of the Solar System account for the dynamical regularities of the Solar System and for the fact that there are two main types of planets in our Solar System?

Back 9

The condensation theory for origin of solar system accounts for regularities because it would make sense that planets rotate in the same sense as they are created.
-Also, there are two types of planets because the system cooled down faster in the center and that allowed planets to get bigger.

Front 10

Planets that are are icy and cold rocks.

Back 10

Dwarf Planets

Front 11

Why are the Jovian planets so much more massive than the Terrestrial planets?

Back 11

-Jovian planets are more massive because they had more time to develop, as oppose to terrestrials that cooled down more quickly.

Front 12

What is the Snow Line?

Back 12

-Snow-line is where water freezes, it is significant because it shows where it would be harder for planets to solidify

Front 13

What are refractory elements?

Back 13

-Refractory elements vaporize at high temps

Front 14

What are volatile elements?

Back 14

- Volatile elements vaporize at low temps

Front 15

What are planetesimals?

Back 15

-Planetesimals are small dust particles

Front 16

What are proto-planets? Describe how they fit into the scheme for Solar System formation.

Back 16

-Proto-planets are large enough objects to attract mass to them to be even larger

- As dust particles collide the form bigger, and bigger objects which fits current though regularities. Jovian planets are different because proto-planets that will become Jovian attract Helium and Hydrogen from the solar nebula.

Front 17

What is the current understanding as to why Jupiter/Saturn and Uranus/Neptune are so different?

Back 17

Jupiter/Saturn had more time to develop with more gas, whereas Uranus/Neptune did not have as much to develop as the sun lit up.

Front 18

What is meant by accretional heating?

Back 18

-Accretional heating As the planets formed through the accretion of planetesimals, they heated due to the violence of the collisions.

Front 19

Radioactive heating?

Back 19

-Radioactive heating Some atomic nuclei are not stable. If they are allowed to sit, they will spontaneously break apart into smaller nuclei releasing particles and energy. The shorter half-life nuclei add to the initial heating of the planets while the longer half-life nuclei add to the current heating of the interiors of the planets (the interiors of some of the Terrestrial planets are still quite hot.

Front 20

What are the primary nuclei that heat the Earth?

Why are these important for the chemical differentiation?

Back 20

-Iron and Nickel nuclei heat- Earth-like (terrestrial planets)
-Chemical differentiation is that denser chemicals sink to the center of the Earth. Leads to layers of the crust.

Front 21

radioactive age dating to determine the age of a rock. What are some important elements used for radioactive age dating? Explain how you could judge the age of rock.

Back 21

Radioactive elements provide accurate clocks. If one can measure the relative abundances of the radioactive element (parent) and the decay product (daugher), one can infer the age of the rock through the half-life of the material. The half-life of an element is the time it takes for one-half of the parent nuclei to decay (transmute) to the daughter nuclei.

Front 22

The layers of the Earth defined by their chemical composition are ____, _____, and _____ . Do other planets show a similar structure?


Back 22

The Terrestrial planets are divided into regions depending on the chemical composition of the material. The planets are divided into the crust, mantle, and core. The crust and mantle are composed of silicates; the core is composed of iron and nickel.

Front 23

The layers of the Earth defined by their mechanical properties are ____ and ____. Describe the properties of these layers. How are these layers differentiated (that is, what mechanical properties are used to define these layers?) Compare and contrast the other Terrestrial planets to the Earth in terms of this structure.


Back 23

The best way to look at the structure of the Earth from a mechanical standpoint. It turns out that the crust and the outer part of the mantle form a rigid unit, the lithosphere, which sits upon a plastic layer (which can "flow") known as the asthenosphere. Below the asthenosphere sits the core material.


-asthenosphere- Plate tectonics sit, mechanically weak

-lithosphere- the crust, solid or covered with water

Front 24

List the ways astronomers probe the interiors of the Terrestrial planets. What has been the most useful method for the Earth?

Back 24

Seismology
Magnetic Fields

Front 25

What has been the best method for Mercury?

Back 25

on mercury we shoot radio signals that pick up wobbles in its rotation which suggest a liquid core.

Front 26

What are P waves?

Back 26

the P(rimary) waves, the wave again moves from left-to-right, while now the disturbance is in the same direction. This wave is like a wave you make with a slinky (a spring). The spring alternately compresses and expands with the coils of the spring moving in the same direction in which the wave propagates. These waves are also known as pressure waves or longitudinal waves.

Front 27

What are S waves?

Back 27

the S(econdary) waves, the waves moves from left-to-right, while the disturbance moves up and down (perpendicular to the direction of wave propagation). This wave is like the disturbance you would make is you snapped a whip or if you were to shake a rope. These waves are also known as shear waves

Front 28

What are the Shadow Zones?

Back 28

-Shadow Zones: The shadow zone is the area of the earth from angular distances of 104 to 140 degrees from a given earthquake that does not receive any direct P waves. The shadow zone results from S waves being stopped entirely by the liquid core and P waves being bent (refracted) by the liquid core.

Front 29

Compare the interiors of the Earth and the Moon.

Back 29

Earth has 3 layers- Core, Mantle, Crust
Moon has 2 layers, small core, large mantle

Front 30

Describe the surface features on the Moon. What are the oldest regions? What are the youngest regions?

Back 30

The Moon is divided into two types of terrain:
maria, the lightly cratered, dark-colored lowland basins which cover 15 % of the lunar surface
the light-colored, heavily cratered highland regions which cover 85 % of the lunar surface. Because of their heavy cratering, the highland regions are inferred to be ancient while the lightly-cratered maria are inferred to be young (younger). Similar types of features are seen on Mars and Mercury.

Heavy cratering maria- older
Light cratering maria- young

Front 31

How are their absolute ages determined?

Back 31

Radioactive aging helps with process of determining age of craters

Front 32

How were maria formed?

Back 32

maria- the lightly cratered, dark-colored lowland basins which cover 15 % of the lunar surface