Astronomy Term Two Test Learning Outcomes Flashcards
studying for term two test (celebration of intelect
name the terrestrial planets
mercury, venus, earth, mars, (moon)
name the existing moons of each terrestrial planet
mercury ; none
venus ; none
earth ; one (THE moon)
mars ; two (phobos and deimos)
what are the steps in terrestrial planet formation
first; the planet forms and energy turns into thermal energy in the planet’s interior.
second; differentiation converted additional energy as the denser materials sank to the core
third; radioactive materials decay and release heat into planetary interiors
what are the 3 layers of all terrestrial worlds interiors?
Core, Mantle, Crust
What is the density of the core?
the core is always made of the highest density materials such as metals (remember that this was the densest material as it sunk to the CORE during differentiation)
What is the density of the mantle?
The density of the mantle is moderate, as this is the material with high enough densities to sink past the crust but not dense enough to exist within the core.
What is the density of the Crust?
this is the lowest density, makes up our earths skin.
2 geological features of earth
All 4 geological processes exist on earth
Earth is unique for our tectonic plate processes
2 geological features of the moon
the moon is geologically dead
has few tectonic features but no evidence for recent geological activity
2 geological features of mars
evidence for all 4 geological processes but no active volcanism or tectonics
has present water but only in the form of water ice
2 geological features of mercury
considered geologically dead
few tectonic features bot no evidence for recent geological activity
2 geological features of venus
active volcano
impact craters (far less than the moon, mercury and mars tho)
4 surface shaping features of the terrestrial worlds
- Tectonics
- Impact Craters
- Volcanism
- Erosion
Role of internal heating in terrestrial planets surface features
Internal heating is required for volcanic and tectonics
What makes up earths atmosphere?
Nitrogen, Oxygen, Small amounts of other gases
What makes up Mercury’s atmosphere?
Helium, Sodium and Oxygen
What makes up Mars’ atmosphere?
Carbon Dioxide, Nitrogen, Argon
What makes up Venus’ atmosphere?
Carbon Dioxide, Nitrogen
What is the Greenhouse Effect?
The greenhouse effect is what prevents our planet from freezing. It is the process of greenhouse gasses in an atmosphere warming the planets surface.
What is the Runaway Greenhouse Effect (aka) Positive Feedback Loop
The concept in which evaporation (& greater capacity for water-vapor) causes more water-vapor, causing more greenhouse gasses, causing planetary temperatures to rise, causing more evaporation, more water-vapor, more greenhouse gas, higher planetary temperatures (and a continuous loop until the planet inevitably becomes geologically dead)
What are the causes of climate change?
Human activity causes excess greenhouse gasses.
Difference between the greenhouse effect and the ozone hole
the greenhouse effect is a natural process that allows planetary surfaces to warm due to trapped gasses.
The ozone hole is in place due to human behavior driving excess greenhouse gasses causing temperature to rise in our atmosphere and damaging it.
Name the Jovian Planets
Jupiter Saturn Uranus Neptune
Jovian Planet Formation
Jovian planets formed in the cold reaches of the solar system, far from the sun. Due to this their cold temperature allowed the hydrogen compounds to turn into ice, and grow large enough to create a gravitational pull to draw in hydrogen and helium surrounding them and grow larger.
Jovian vs Terrestrial Planet Formation
Jovian planets draw in hydrogen and helium from their surroundings and grow. Terrestrial planets formed in regions that were hot enough to allow the process of differentiation.
Name the 6 Jovian Moons
Io, Europa, Ganymede, Calisto, Titan, Enceladus
Which Planets Home the Jovian Moons?
Jupiter ; Io, Europa, Ganymede, Calisto
Saturn ; Titan, Enceladus
Why do the Jovian Planets appear as different colors?
different chemical compounds allow the Jovian planets to appear as different colors.
methane causes Uranus and Neptune’s cloud to appear as blue.
What is the expected lifetime of Jovian ring systems?
Larger particles in the Jovian rings are constantly being ground down by impacts of surrounding particles. New particles are constantly being supplied, to replace those that are destroyed. Ring particles cannot last for billion years, so the rings we see today are compiled of recent particles.
What is the composition and location of Asteroids
COMPOSITION
Majority of asteroid’s (75%) are Carbonaceous. There are also Silicate Asteroids which are rocky (17%) and Metal Rich Asteroids (8%)
LOCATION
The vast majority of Asteroids orbit the sun in the asteroid belt between Mars and Jupiter. Jupiter’s gravity shapes their orbits and prevents asteroids from accreting into a planet.
What is the composition and location of Comets
COMPISITION
Composed of ice and rocky dust. Ice begins to vaporize and escape as comet ascends towards the sun, creating the comets tails (Plasma and Dust Tails)
LOCATION
Many comets come from the Oort Cloud or Kuiper Belt.
What is the composition and location of Kuiper Belt Objects
COMPOSITION
The Kuiper Belt is comprised of icy objects. Many objects in the belt should have similar compositions to Pluto as they formed in the same region.
LOCATION
Objects in the Kuiper Belt reside in the Kuiper belt, located far beyond the orbit of Neptune.
What is the composition and location of Dwarf Planets
COMPOSITION
dwarf planets are objects that are not large enough to be considered a planet, but large enough to be spherical.
LOCATION
There are 5 recognized Dwarf planets. Ceres lies in the main asteroid belt (between Mars and Jupiter) where the rest reside in the Kuiper Belt.
Where does the Main Asteroid Belt reside?
Between Mars & Jupiter
How do Small Bodies differ from our 8 Planets in our Solar System?
small bodies are too small to be considered planets.
What is the Gravitational Influence of the planets on small bodies?
Impacts are always in some way related to the gravitational impacts of the Jovian planets. These influences have shaped the Kuiper belt, the Oort cloud, and determine when an object is flung where.
Why should Pluto be considered a Kuiper Belt Object?
Pluto is smaller and icier and more distant than all planets. Scientists believe that all objects in the Kuiper belt have similar compositions to Pluto.
What is the Asteroid Impact on Earth?
an impact could cause widespread physical impact. Asteroid impact caused extinction of 99% of all living organisms to die. Smaller impacts occur every couple hundred years.
What are 2 famous impacts from asteroids?
Tunguska Siberia & Chelyabinsk Russia
What is a Meteor?
a flash of light caused by a particle of dust or rock entering our atmosphere at high speed (shooting or falling stars)
What is a Meteoroid ?
a small to boulder sized particle of debris in the solar system
What is a Meteorite?
a rock large enough to enter the atmosphere, survive and reach the ground
What are the 2 ways to discover Exoplanets
- Direct Imaging
- Indirect Imaging
What is Radial Velocity?
radial velocity (doppler shift) method measures changes in the stars velocity, detecting through the motion of a star.