Mars Research Flashcards
What is the diameter of the Milky Way? (In light years)
100,000 light years
Astronomical Unit (AU)
The distance between the Earth and the sun (150 mil km)
How long does it take for Mars to orbit around the sun?
687 earth days, 1.88 earth years, 669 Martian sols
Mars surface area is what percent of earth’s?
38%
Mar’s diameter is what percent of earth’s
53%
What are Mars and earth’s average orbit speed around sun?
Earth: 18.5 miles per second
Mars: 14.5 miles per second
What is Mars and earths length of day?
Earth: 23 hr 56 min
Mars: 24 hr 37 min
What is mars is gravity in comparison to earth?
0.375
Mars average temperature
-81 F
Mar’s Moons
Phobos/ Deimos
Mar’s atmosphere
Mostly carbon dioxide
Mars habitable timeframe
4.1 to 3 billion years ago
Perhelion
The point in the orbit of a planet, asteroid, or comet at which it is closest to the sun.
Arsecond
A unit of angular measurement (1 degree= 3600 arcseconds)
Arcminute
A unit of angular measurement (1degree= 60 arcminutes)
Planetary Opposition
When the Earth is directly between the planet at opposition and the sun, forming a straight line. The planet is brighter and visible in the night sky, and is closer in proximity to Earth (Saturn, Jupiter, Mars)
How far apart are Earth-Mars opposition? (In days)
Approx. 780 days apart
Eccentric Orbit
- The planet’s distance from the sun varies throughout it’s orbit.
- Varying orbit speed: the planet moves faster at perihelion and slower at aphelion.
Albedo
The reflection of a celestial body’s surface. It’s the fraction of solar radiation reflected back into space often expressed as a percentage. High albedo means more reflection and low albedo indicates more absorption of incoming sunlight.
Opacity
The degree to which the atmosphere obstructs the passage of light through how much it scatters or absorbs incoming radiation, affecting visibility and the transmission of sun through the atmosphere.
High Opacity means less transparency often due to factors like particles or gases in the atmosphere.
Two Types of Martian Clouds
- Yellow clouds: dust storms
- White clouds: condensate
What hemisphere and when do yellow dust clouds often occur?
- Region: Southern Hemisphere
- Timing: Southern Hemishere’s spring and summer at perihelion.
What is the degree of Earth’s axial tilt?
Approx. 23.5 degrees
Obliquity
The tilt of a planet’s axis in relation to it’s orbital plane around the sun.
How does obliquity impact the potential habitability of a planet?
- Seasonal Variations: variations in the duration and intensity of sunlight at different latitudes throughout the year= distinct seasons.
- Temperature Extremes: a planet with a very high or low obliquity might experience significant temperature extremes, making it potentially challenging for life.
- Climate Stability: moderate obliquity can contribute to climate stability. Too much variation in climate over time could be detrimental to the development and sustainability of life.
- Ice cap dynamics: significant obliquity= polar ice caps might expand and contract dramatically, effecting sea levels and regional climates.
Mars Obliquity (present day)
Approx. 25.1 degrees
Maximum possible variation for Mars obliquity
14.9 to 35.5 degrees
Sol (sols)
Martian days
Martian year
- Areocentric solar day
- Areosynchratic year
How is Areocentric Longitude of the Sun abbreviated?
Ls
Areocentric Longitude
A way of describing Mar’s orbit around the sun using an angle measured to where in the Martian year the planet is.
What is the eccentricity value of Mars?
0.093
What is the eccentricity value of Earth?
0.017
How far is Mars for the sun during perhelion? (Au)
1.381 Au
How far is Mars from the sun at aphelion? (Au)
1.666 Au
Solar Flux
The amount of solar energy and radiation received per unit of time, per unit of area, and per unit of frequency.
Often expressed in watts per square meter (w/m^2)
What is the difference in percentage of solar flux on Mars between perhelion and aphelion?
Mars receives 45% more sunlight at perhelion than aphelion.
When does present day Martian perhelion occur?
At the end of southern spring, so southern springs and summer are hotter than the same seasons in the north.
Why are southern springs and summer shorter than the same seasons in the northern hemisphere of Mars?
Southern spring and summer at shorter due to higher orbital velocity closer to perhelion.
Apsides
Two extreme points in an orbit around a celestial body, such as a star or planet (involving eccentricity)
Periapsis
Point in orbit where an object is closest to the body it is orbiting (perhelion)
Apoapsis
Point in an orbit where an object is the farthest from the body it is orbiting (aphelion)
Hertz (Hz)
The unit of frequency, representing cycles per second.
Gigahertz (GHz)
Equivalent to 1 billion hertz, meaning the signal completes 1 billion cycles per second.
Ions
Electrically charged particles that result from the loss or gain of electrons by an atom.
Cations
Positively charged ions formed when an atom loses one or more electrons- since electrons are negatively charged, removing them leaves a positively charged ion.
Anions
Negatively charged ions formed when an atom gains one or more electrons. The addition of negative electrons results in a negatively charged ion.
Ionization
When enough energy is provided to an atom to remove one or more electrons.
Can happen through various means: exposure to high energy radiation (UV light), collisions with other particles, or by chemical processes
Ionic bonding
Formation of ionic bonds between positive cations and negative anions.
Electrolytes
Ions in solution conduct electricity and substances that dissociate into ions in a solution are known as electrolytes.
Ionosphere
Earth’s ionosphere contains ions created by the ionization of atoms and molecules by solar radiation.
Region if Earth’s upper atmosphere, extending from 30 miles to 600 miles above Earth’s surface.
Ionosphere Main layers
D, E, and F (F1 and F2)
Roles of Ionosphere
It reflects certain frequencies of radio waves, allowing long distance communication via the reflection of signals back to the Earth’s surface.
Influences Earth’s magnetic field and participates in various ionospheric phenomena like auroras.
Ionospheric Variability
Properties can vary depending on factors such as solar activity, time of day, and geographic location. Solar flares and geomagnetic storms can have a significant effects on the ionosphere.
E Layer
Altitude: 34-56 miles above Earth
Ionization: primarily by solar x-rays
Characteristics: the E layer is more persistent than the D layer and can influence radio wave propagation. It reflects medium frequency (MF) and high frequency (HF) radio waves, allowing long distance communication via the reflection of signals back to earth.
D Layer
Altitude: 18-34 miles above Earth’s surface.
Ionization: primarily ionized by extreme ultra violet (EUV) solar radiation.
Characteristics: the D layer is most ionized during the day and tends to disappear at night due to recombination processes. It absorbs lower frequency radio waves, particularly during daylight hours, making it challenging for long distance radio communication at these frequencies.
F Layer
Altitude: 56-373 miles above Earth
Ionization: the F layer is further divided into F1 and F2 layers. These layers are ionized by solar extreme ultra violet light (EUV) and x-ray radiation
F1 layer
Found at lower f layer altitudes
Becomes significant during the day
F2 layer
Found at higher altitudes within the F layer.
Layer most critical for long distance radio communication.
Energy
The capacity to do work or the ability to cause a change in the state of motion of an object.
Energy unit
Joule (J)
Forms of Energy
Kinetic (motion)
Potential (position)
Thermal energy
The total energy of a system is conserved, meaning it remains constant unless..
Acted upon by external forces
Power
The rate at which energy is transferred, converted, or work is done.
Power Unit
Watt (w)
Power equation
Energy/ time= power
Radio wave propagation
Behavior or movement of radio waves as they travel from a transmitting antenna to a receiving antenna.
Influencing factors: frequency of radio waves, atmospheric conditions, and the presence of obstacles or reflecting surfaces.
Gigayear (Gyr)
Unit of time equal to a billion years
Ground wave propagation
Waves follow the Earth’s surface suitable for short and medium range communication.
Sky wave propagation
Radio waves are refracted by the ionosphere, allowing for long distance communication- short term radio
Line of sight propagation
Waves travel in a straight line and require a clear line of sight between the transmitting and receiving antennas. Common in microwave communication.
Electromagnetic Spectrum (Longest to shortest wavelengths)
- Radio waves
- Microwaves
- Infrared Radiation (IR)
- Visible Light
- Ultraviolet Radiation
- X- rays
- Gamma Rays
Martian crust is heavily
Balsaltic
Triple point of water
Thermodynamic state where water co- exists in equilibrium as solid ice, liquid water, and water vapor.
Millibar (mbar)
Unit of pressure
Equipotential
Surface where the gravitational potential is the same at all points.
Earth’s atmospheric layers
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
- Exosphere
Troposphere
5-9 miles above Earth’s surface
Contains air we breath and where weather phenomena occur.
Stratosphere
9-31 miles above Earth’s surface.
Ozone layer is located in the lower stratosphere- important for absorbing and blocking UV radiation from the sun.
Mesosphere
31-53 miles above Earth’s surface
Where meteorites burn upon entering Earth’s atmosphere
Thermosphere
53-373 miles above Earth’s surface
Significant increase in temperature with altitude.
Auroras occur here
Contains a small percentage of Earth’s atmosphere by mass
Exosphere
Outmost layer of Earth’s atmosphere and it extends into space- gradually
Annulus
Ring shaped object or space
Conductive Heat Exchange
Transfer of heat through direct contact between materials with different temperatures.
Kinetic energy is transferred from the more energetic particles of one substance to the less energetic particles of another.
Ballistic Trajectories
Paths that objects follow under the influence of gravity and no other forces
Vertical Motion
Movement along vertical axis (up and down).
Influenced by the force of gravity, causing objects to accelerate downwards and decelerate upwards.
Horizontal Motion
Movement along the horizontal (left right) axis.
In the absence of external horizontal forces, motion is typically uniform and the object moves at a constant speed.
Projectile Motion
The motion of an object that is thrown or projected into the air and subject only to the force of gravity and air resistance.
Combination of horizontal motion with a constant velocity and vertical motion with constant acceleration due to gravity.
Independence of motion
The horizontal and vertical motions are independent of each other.
Horizontal motion continues at a constant velocity and vertical motion is influenced by gravity.
Curved Trajectory
Combination of horizontal and vertical motions results in a curved trajectory (parabola)
Equal times of flight
Objects launched at the same initial speed but different angles will spend the same amount of time in the air and land at the same time.
Diffusion
Movement of particles from areas of higher concentration to areas of lower concentration.
Isotope
Two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei.
Differ in relative atomic mass but not in chemical properties.
