Final Exam

Question 1

Why is the upper atmosphere important?

Answer 1

• High Energy radiation absorbed in the upper atmosphere influences the chemical reaction that can take place
• Absorbs most of the harmful ultraviolet

Question 2

The layers of the atmosphere (Lowest to Highest) AND Characteristics

Answer 2

1) Troposphere
2) Stratosphere (Ozone layer)
3) Mesosphere (Radiative Cooling)
4) Thermosphere (X-ray, particle energy input heats layer)

Question 3

Qualitatively how the density changes in a hydrostatic atmosphere

Answer 3

Density decreases as it goes up the atmosphere

What is hydrostatic atmosphere?

• Balance between
• Hydrostatic Equilibrium

Question 4

How does the ionosphere form?

Answer 4

The ionosphere is formed by ionization of the three main atmoshperic constituents N2, O2, and O.

Question 5

How is the chapman layer formed?

Answer 5

• Number of photons is largest at top of ionosphere and decreases with decreasing altitude
• The number of neutrals
  is largest at bottom of atmosphere and decreases with increasing altitude
• Combining two profiles gives profile of the chapman layer

Question 6

How is the Aurora formed?

Answer 6

• Energetic particles whether from magnetosphere or the sun comes and interact with the atmospheric gases giving them energy, then this energy is released in the form of different aurora lights

Question 7

Different Satellite orbits and their advantages

Answer 7

1) Low Earth Orbit (LEO) - 100-1500km
- Easiest and least expensive
- Cost is about a factor of ten cheaper large rockets required to get satellites higher into space
2) Medium Earth Orbit (MEO) - 5000-10000km
- Launches higher then LEO which means less satellites are needed into higher orbits
- Reduced delay
3) Geostationary Orbit (GEO) - 36000km
- Assure even wider coverage of earth
Satellite always in same position relative to earth, antennas do not need orientation
4)Highly Elliptical Orbit (HEO)

Question 8

How do space weather phenomena affect atmospheric drag on satellites?***

Answer 8

Atmospheric drag is friction between object and the atmosphere as the object moves
- Atmospheric drag is reduced as altitude and temperature increases because density of air is reduced at higher altitude and temperatures

Question 9

How do the changes in the radiation belts caused by space weather effect satellites

Answer 9

• Surface Charging
• Deep Dielectric Charging
• Single event upsets
• UV Degradation

Question 10

How do space weather phenomena affect power systems on earth? ***

Answer 10

• Electric fields can drive currents that burn out transformers
• Faradays law of induction
• > Phenomenon is known as electro magnetic induction
• > Any change in the magnetic environment of a coil of wire will cause a voltage (emf) to be “induced” in the coil
• > No matter how the change is produced, the voltage will be generated

Question 11

What is Surface Charging and the effects?

Answer 11

• Caused by interaction between a space craft and the low energy electron environment of space
  EFFECTS are spurious electric switching; Breakdown vehicle thermal coatings; Degrade amplifiers and solar cells; Degrade optical sensors

Question 12

What is Deep Dielectric Charging and the effects?

Answer 12

• Deep dielectric charging and discharging is one of the most common and catastrophic regarding spacecraft electronics and radiation
  EFFECTS -> Can build up to such an level that the dielectric material breaks down and flow through these new pathways on the circuit board

Question 13

What is Single event upsets and the effects?

Answer 13

• Due to penetrating ions that can “trigger” an electronic circuit
  EFFECTS -> Can cause a switch or computer memory to “flip” which could then turn off or otherwise give an unintended signal to the spacecraft
  -Damage to stored data; Damage to software; stop central processing unit (CPU); Cause CPU to write over critical data tables; Create faulty commands; Faradays law of induction

Question 14

What is UV Degration and the effects?

Answer 14

• Much more intense in space then on the surface of earth EFFECTS -> Degrade certain materials, particularly plastics and other organic materials

Question 15

How are radio transmissions affected by space weather? ***

Answer 15

• Polar flights, Space weather degradation of HF radio
• GPS, Modify the density distribution of the ionosphere, radio wave propagation depends on medium the waves move through
• Pipelines

Question 16

Keplers law of planetary motion

Answer 16

1) The Law of Orbits: All planets move in elliptical orbits, with the sun at one focus
2) The Law of Areas: A line that connects a planet to the sun sweeps out equal areas in equal times
3) The Law of Periods: The square of the period of any planet is proportional to the cube of the semi major axis of its orbit

Question 17

Center of Mass

Answer 17

• Most objects have their mass spread out through the object (i.e. Mass of earth is spread out the volume of the spherical Earth)
• Point that is weighted average of distribution for that object
• EXAMPLE, for a baseball bat the center of mass is near the thicker part of that object

Question 18

Ohm’s law

Answer 18

• Ohms law is when the voltage equals to the current times the resistance: V = IR
• Metals and water have very low resistance (Flows easily), while wood, rubber and air have resistance, This relationship is called Ohm’s Law

Question 19

What is the main risk to humans from space weather effects?

Answer 19

• Ionizing radiation
• Direct ionization (Particle radiation interactions with living tissue) , indirect ionization (Process involving electromagnetic radiation)
• Different types of radiation have different biological effects
• Galactic Cosmic Rays

Question 20

What are the problems of long duration space travel?

Answer 20

• Vacuum of space
• Low gravity
• Micrometeoroids

Question 21

What is Special Relativity?

Answer 21

• Describes motion of objects that are moving to speed of light ( 3x10^8 m s^-1 )
• Time dilation
• Length contraction

Question 22

Difference between weather and climate?

Answer 22

• Weather is mic of events that happen each day in our atmosphere including temperature, rainfall and humidity. Weather is not the same everywhere
• Climate in your place on globe controls weather where you live. Climate is the average weather pattern in a place over many years. Climate of Antarctica is different than climate of tropical island

Question 23

What is the Milankovitch cycle?

Answer 23

• Milankovitch cycles are caused by changes in the earths orbit (100000 yrs), rotation (40,000yr) and wobble of its axis (26 000yr)
• Cyclical movement related to the earths orbit around the sun. There are three of them: eccentricity, axial tilt, and precession

Question 24

What is the Maunder Minimum?

Answer 24

• Prolonged sunspot minimum, period around 1645 to 1715 during which sunspots became exceedingly rare, as was then noted by solar observers

Question 25

What is the little age?

Answer 25

The little age was the period condided with a time of extremely cold winters and cool summers in Europe and North America

Question 26

What is climate variability and space weather?

Answer 26

• WE know that the luminosity of the sun hardly changes at all over the 11 year solar cycle
• Total luminosity changes by about 0.1% between solar minima and solar maxima
• Changes in UV and X ray intensity can have important consequences on total energy balance of atmosphere
• Clouds play an important role in climate

Question 27

Asteroid and comet impacts

Answer 27

• Asteroids are considered minor planets
• Other rocky particles that are far away not captured by any planets gravitational system to end up as moons orbiting a planet
• Asteroids rarely collide but when they do forces can cause an asteroid to nudge out of a belt into a gap

Question 28

Difference between Asteroid, meteroid, meteorite and comet

Answer 28

• METEOROID is a small rocky or metallic body travelling through space and is significantly smaller than an asteroid
• COMET is an icy solar system body, when passing close to the sun, displays a visible coma and sometimes a tail
• METERORITES are objects that actually hit the earths surface
• ASTEROIDS are considered minor planets

Question 29

What is a nearby Supernova?

Answer 29

• Once every 50 years a massive star explodes somewhere in milky way, blast is powerful, pumping out more energy in a split second than the sun emits in a million years
• Two types of Supernova, Type I and Type II

Question 30

What is Type I Supernova?

Answer 30

Occur in binary star systems when white dwarf star accretes or attracts material form its main sequence companion

Question 31

What is Type II Supernova?

Answer 31

Occur when a star much more massive than the Sun exhausts its supply of nuclear fuel, thermonuclear reactions cease, and the star collapses under its own gravitational force

Question 32

Kinetic Energy and conservation of energy

Answer 32

• Energy come sin many different forms: Mechanical, chemical, and electrical
• MECHANICAL ENERGY is energy that an object has due to its motion (kinetic energy) or its potential energy due to its stored energy of position
• CHEMICAL ENERGY is the potential energy contained in the bonds between atoms
• CONSERVATION OF ENERGY states that the total amount of energy in a closed system must be conserved