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Planetary and Geological Science
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Planetary and Geological Science
Planetary and Geological Science
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1
Question
How does the gravity of a newly formed star influence planet formation?
Answer
Gravity from the star prevents remaining nebula material from being lost to space.
2
Question
How do solar winds from a star influence planet formation?
Answer
Generation of solar winds moves elements within the spinning disk of the nebula, prevents more material from being forced into the star, and creates winds that push things outward, forming stable orbits.
3
Question
How do planetesimals form and contribute to the development of celestial bodies?
Answer
Spin continues in the former nebula, new regions are formed that concentrate materials for planet formation. Planetesimals accrete together, forming planets, asteroids, and comets.
4
Question
Why are rocky planets closer to the sun and gas/ice planets further away?
Answer
Rocky planets (Mercury, Venus, Earth, Mars) are closer to the star, while gas/ice planets (Jupiter, Saturn, Uranus, Neptune) are further away due to solar winds.
5
Question
What evidence supports the disk model of solar system formation?
Answer
Images of different star formations, telescopes, H and H composition of nebula via spectroscopy, and radioactive dating of stars.
6
Question
What are the major layers of the Earth and their primary compositions?
Answer
Inner core (solid, mainly Ni and Fe), outer core (liquid, mainly Fe and Ni), lower mantle (mainly rock), upper mantle (mainly rock), crust (thin layer where life exists).
7
Question
How do we determine the composition of the Earth's interior without direct observation?
Answer
By interpreting the timing and behavior of seismic waves (P-waves vs. S-waves).
8
Question
How was the Moon formed?
Answer
A protoplanet called Theia collided with the developing Earth, and the debris accreted together to form the Moon.
9
Question
What important processes have shaped the Earth?
Answer
Plate tectonics, magnetic field, outgassing as rock cools, and bombardment.
10
Question
What is the habitable zone (Goldilocks zone)?
Answer
The habitable zone is the distance from a star where liquid water and gaseous CO2 can exist.
11
Question
Why is planetary mass important for a planet's habitability and geological activity?
Answer
Retaining atmosphere and ocean through gravitational attraction, generating internal heat for plate tectonics, climate control, and continuously changing the Earth's surface.
12
Question
Why is the right planetary mass important for a planet to be fit for life?
Answer
Generates enough internal heat for plate tectonics to occur.
13
Question
Why is a large metallic core important for a planet to be fit for life?
Answer
Large enough to produce a mixed solid and molten core with elements generating a magnetic field (Fe and Ni).
14
Question
Why are Plate Tectonics important for a planet to be fit for life?
Answer
We are the only solar system planet with Plate Tectonics. Builds up land mass terrestrial habitats and causes sea level changes. Enhances biotic diversity, glaciations and ocean circulation, volcanic islands, mountains, connecting and separating habitats. Major implications on human history and cultural evolution. Recycling of carbon in the carbon cycle.
15
Question
Why is having a Jupiter-like neighbor important for a planet to be fit for life?
Answer
Exerts large gravitational influence. Cleaned out most of the large stray bodies that existed early on in the inner Solar System. Helps clear out comets and asteroids that approach inner Solar System.
16
Question
Why is having a large moon important for a planet to be fit for life?
Answer
Helps offset gravitational pull from Jupiter and the Sun. Stabilizes tilt or obliquity which is the cause of seasonal changes provides right amount of climate variation to stimulate evolution. Tidal zones may have been very important for earliest life forms: nutrient-rich, diverse habitats, protection for UV.
17
Question
How was Earth replenished with a new atmosphere and water after the aftermath of Theia?
Answer
Volcanic outgassing of magma ocean material replenishes Earth with new atmosphere, including water OR bombardment by icy meteorites/water.
18
Question
What are Tectonic Plates?
Answer
Large subdivisions in the crust of the planet, generally in motion over long geological time scales.
19
Question
What is plate tectonics?
Answer
Study of movement of tectonic plates.
20
Question
How do tectonic plates move?
Answer
Temps are hot enough that rock behaves as a liquid (molten). Within liquid region of the asthenosphere, movement of liquid rock driven by differences in temp and density. Colder denser sinks. Hotter less dense rises. Differences in temp between the outer and inner layers of the
21
Question
What is Oceanic Crust?
Answer
Has a density of 2.9-3 g/cm3. Mainly uniform thickness of 5km. Fe- and Mg rich. Mainly found under oceans but exceptions exist.
22
Question
What is Continental Crust?
Answer
Less dense than oceanic. Thicker than oceanic. Made mostly (90%) of Silicates like CaSiO3. Generally found out of water exceptions exist. Acid rain falls on silicates carbonic acid source of minerals from continental crust, carbon silicate cycle.
23
Question
What drives the movement of tectonic plates?
Answer
Convection currents in the mantle.
24
Question
List the three types of tectonic plate interactions.
Answer
Divergent, Convergent, and Transform boundaries.
25
Question
Describe the push-pull process in tectonic plate movement.
Answer
Creation of new plate at ridges (push), destruction of plates at subduction zones (pull), and easy movement of plates by floating of solid plates over liquid base in asthenosphere.
26
Question
What occurs at a divergent boundary?
Answer
Two plates pull apart, forming new oceanic crust from rising magma, often with hydrothermal vents.
27
Question
How do magnetic pole reversals provide evidence for seafloor spreading?
Answer
As new rock solidifies at divergent boundaries, minerals align with Earth's magnetic field, recording reversals over time.
28
Question
What is a subduction zone?
Answer
An area where one plate is forced under another at a convergent boundary.
29
Question
Where are volcanoes commonly located?
Answer
At subduction plate boundaries, known as the Ring of Fire.
30
Question
Describe the three types of convergent boundaries.
Answer
Ocean-Continent, Ocean-Ocean, and Continent-Continent.