Benchmark #4 Flashcards
What is the term “Big Bang” referring to?
The formation of all space, time, and matter.
2.) When was the Big Bang?
13.7 billion years
3.) How is the Doppler effect used to determine the motion of distant galaxies relative to our galaxy?
The color of the light emitted from a star is measures for shift (red or blue) to determine if it is moving toward or away.
4.) If light from distant objects is blue-shifted, is the object moving towards or away from us? What if the light is red-shifted?
Toward. Away
5.) According to our estimates, how many stars are there in the Milky Way Galaxy?
100 billion
6.) What is a nebula?
Cloud of gas and dust in space.
7.) What are four characteristics of a molecular cloud?
- Lumpy, with regions of varying density.
- Particularly cold and dense.
- Areas where stars are born.
- Contain only a small percentage of heavier elements.
What is a protostar?
The dense center of a collapsing molecular cloud fragment that occur during star formation.
The collapse of a molecular cloud occurs due to what?
Gravity
What is the difference between nuclear fusion and nuclear fission?
Fusion is the combining of nuclei and fission is the spitting of nuclei of elements.
In what order of elements does the Sun burn through its fuel supply?
Hydrogen then helium then carbon
What led scientists to conclude that our Sun is a second-generation star?
The presence of trace amounts of heavier element within the Sun that it isn’t able to produce.
List the five characteristics used to classify stars:
- Age
- Distance from the Earth
- Color
- Temperature
- Apparent brightness
How is our sun classified, according to the Hertzsprung-Russell Diagram?
Main Sequence Star
Be able to use the Hertzsprung-Russell Diagram to match a description of a star to its corresponding location on the diagram (know how to read solar radius, lifetime of a star, surface temperature, star color, the “main sequence stars”, and luminosity)
know diagram
What is the Nebular Theory? What does it describe?
The idea that the solar system was born from a cloud of gas, called the solar nebula. How the solar system was formed.
According to Nebular Theory, what may have caused the initial collapse of the solar nebula?
A cataclysmic event such as a nearby star exploding.
Know the following 5 steps, in order, that occurred in the prevailing theory of our solar system’s formation:
1. A cataclysmic event initiates the collapse of the solar nebula. 2. The temperature of the solar nebula begins to increase, as it rotates faster and flattens into a disc. 3. Hydrogen and helium remain gaseous, but other materials can condense into solid "seeds." 4. Temperature differences in the nebula cause terrestrial planets to form closer to the center of the nebula and gaseous planets to form farther out. 5. Solar wind from the Sun blows remaining gas into interstellar space.
know these
What are the three main processes that occurred during the formation of our solar system?
- Heating
2. Spinning
3. Flattening
Name three results of the processes involved in solar system formation.
- Planet orbit the sun on nearly the same plane
2. Most planets rotate the same direction
3. The Sun rotates in the same direction as the planets
What part of the relationship between the Sun and the Earth is responsible for the Earth’s seasons?
The angle of the Sun’s rays hitting the Earth.
Are seasons determined by the distance from the Earth to the Sun?
NO
How do the seasons of the Earth correspond to the months of the year in the Northern Hemisphere? The Southern Hemisphere?
Jan-March=winter, April-June= spring, July-Sept=summer, Oct-Dec=fall. Jan-March=summer, April-June=fall, July-Sept=winter, Oct-Dec=Spring
Name three main aspects that are used to explain the cycle of lunar phases?
- Moon is spherical in shape
2. Moon is not self-luminous, but reflects the sunlight
3. Moon circles the Earth once a month
List the eight phases of the moon in the lunar cycle
- new moon
2. waxing crescent
3. first quarter
4. waxing gibbous
5. full
6. wanning gibbous
7. third quarter
8. wanning crescent
.) What are the tides on Earth caused by?
Gravitational relationship between the Earth, Sun, and Moon
What is the main idea of the concept of continental drift?
The continents once formed part of a single landmass called a supercontinent (Pangaea)
How far are the continents moving around the Earth each year?
Centimeters each year
the thin outer shell of earth that consist of the crust and rigid part of the upper mantle.
lithosphere
a deformable layer of the mantle that the lithosphere rides upon.
asthenosphere
The lithosphere is broken into how many tectonic plates?
15
The movement of tectonic plates are driven by what energy source?
Mantle convection caused by the outward transfer of Earth’s internal heat.
two plates move toward each other (mountain range like Himalayan or deep trench)
Convergent boundaries
two plates move away from each other (rift or fissure like the Mid-ocean ridge)
Divergent boundaries
two plates slide past one another (San Andrea’s fault)
Transform boundaries
List three sources of all energy on Earth:
- geothermal energy
2. slow radioactive decay
3. energy from the Sun
What happens to the material in stars when they die?
It returns to space and gets recycled into another star.
A famous astronomer once described humans as being mad of “star stuff”. What did he mean by this statement?
We are made of elements that were created in a star.
- Describe the following structures based on their size. (Solar System, Universe, Galaxy, Nebula, Planet)
From largest to smallest we have the universe, galaxies, nebula, solar system, planet.
- Explain the difference between continental drift, sea-floor spreading, and the Theory of plate tectonics.
Continental drift (the idea that the continents were at one time all together in one super continent called Pangaea and have moved to their present day positions) and sea-floor spreading (new sea-floor is created at the Mid Ocean Ridge and it moves outward like a conveyer belt toward the edges) are ideas developed before plate Tectonics was considered. They both led to the development of the THEORY of plate tectonics.
- What are nebulae and what is their role in the life and death of stars? (3pts)
Nebula, large clouds of gas, provide the raw material needed for the formation of a solar system. When a star dies or blows up in a supernova it form a new nebula that could eventually form a new star.
- Do stars make lighter elements or heavier elements in their cores?
Stars use nuclear fusion to form heavier elements. Hydrogen atoms are combined to form the heavier Helium atoms. After all the hydrogen is converted to helium atoms. After all the hydrogen is converted to helium, the star converts helium into carbon. This process continues to make heavier and heavier elements.
- A famous astronomer once described humans as being made of “star stuff.” What did he mean by this statement?
The heavier elements found in our solar system could not have been created by our sun because it is too small. These elements MUST have come from a super massive star that blew up, creating our Solar nebula which eventually formed our solar system.
- Describe two possible consequences that could occur if we lost our moon.
The tilt of earth would change wildly, this would cause major climatic changes, and ocean levels would change rapidly flooding islands and costal cities. Earth would continually be hit by flying space bodies.
There are many consequences that would occur if we lost the moon. First, we would be continually to hit the Earth. Also, our climates would drastically change because we would wobble on our axis.
