Untitled Flashcards Set

KEY Moon phases, eclipses, Universal Law of Gravitation, Galaxies, Star Systems, and the Sun Test Review

Short-Answer Questions

1. What causes the phases of the Moon? (Answer: The Moon's orbit around Earth and the reflection of sunlight.)

2. Why do solar eclipses not occur every month? (Answer: The Moon’s orbit is tilted relative to Earth’s orbit.)

3. How does a lunar eclipse differ from a solar eclipse? (Answer: A lunar eclipse occurs when Earth is between the Sun and Moon; a solar eclipse occurs when the Moon is between the Sun and Earth.)

4. What is the difference between the umbra and penumbra? (Answer: The umbra is the darkest part of a shadow, while the penumbra is the lighter outer region.)

5. What happens to the gravitational force between two objects if their distance doubles? (Answer: It decreases to one-fourth of its original strength.)

6. What is the equation for Newton’s Universal Law of Gravitation? (Answer: F = G(m1m2/r^2))

7. What is the primary source of the Sun’s energy? (Answer: Nuclear fusion in the Sun’s core.)

8. What are the effects of the solar wind on Earth? (Answer: Causes auroras and can disrupt electronics and communications.)

9. Why does the Sun’s corona appear hotter than its surface? (Answer: Magnetic fields accelerate particles in the corona.)

10. How does a barred spiral galaxy differ from a regular spiral galaxy? (Answer: It has a bar-like structure at its center.)

11. What type of galaxy is the Milky Way? (Answer: A barred spiral galaxy.)

12. How does an open star cluster differ from a globular cluster? (Answer: Open clusters are younger and loosely bound; globular clusters are older and densely packed.)

13. What is the significance of Hubble’s Tuning Fork diagram? (Answer: It classifies galaxies based on their shape.)

14. What are coronal mass ejections (CMEs) and their effects on Earth? (Answer: Large bursts of solar particles that can disrupt Earth's magnetic field.)

15. What phase must the Moon be in for a solar eclipse to occur? (Answer: New Moon.)

16. What phase must the Moon be in for a lunar eclipse to occur? (Answer: Full Moon.)

17. What is the role of gravity in planetary orbits? (Answer: It keeps planets in orbit around the Sun.)

18. What will happen to the Sun after it exhausts its nuclear fuel? (Answer: It will become a white dwarf.)

19. What are auroras, and how do they form? (Answer: Light displays caused by solar wind interacting with Earth's atmosphere.)

20. What is a binary star system? (Answer: A system with two stars orbiting a common center.)

Key Vocabulary

1. Phases of the Moon - The different appearances of the Moon as seen from Earth, caused by the varying angles of sunlight reflecting off its surface as it orbits Earth.

2. Umbra - The central, darkest part of a shadow, where all direct light is blocked; during an eclipse, this is where totality occurs.

3. Penumbra - The outer, lighter part of a shadow where only some of the light is blocked, causing partial eclipses.

4. Solar Eclipse - An astronomical event that occurs when the Moon moves between the Earth and the Sun, temporarily blocking sunlight and casting a shadow on Earth.

5. Lunar Eclipse - An event that happens when Earth moves between the Sun and the Moon, causing Earth's shadow to be cast on the Moon, making it appear darker or reddish.

6. Gravity - The attractive force exerted between two masses; it governs the motion of celestial bodies and keeps planets in orbit around stars.

7. Newton’s Universal Law of Gravitation - A scientific law stating that every mass attracts every other mass with a force proportional to their masses and inversely proportional to the square of their distance.

8. Orbital Path - The continuous trajectory that an object follows around another celestial body due to gravitational forces, such as the Moon orbiting Earth.

9. Core (of the Sun) - The innermost region of the Sun where nuclear fusion occurs, generating immense energy that powers the Sun and emits light and heat.

10. Photosphere - The outermost visible layer of the Sun’s surface that emits the light we see; it has a temperature of approximately 5,500°C (9,932°F).

11. Corona - The Sun’s outermost atmospheric layer, extending millions of kilometers into space, visible as a halo during a total solar eclipse.

12. Solar Wind - A continuous flow of charged particles (plasma) released from the Sun’s corona, which can influence Earth's magnetic field and cause auroras.

13. Coronal Mass Ejection (CME) - A powerful eruption of plasma and magnetic fields from the Sun’s corona, capable of causing geomagnetic storms on Earth.

14. Solar Prominence - A large, bright, loop-shaped structure of plasma that extends from the Sun’s surface, often associated with sunspot regions.

15. Star System - A group of two or more stars gravitationally bound and orbiting around a common center of mass.

16. Binary Star System - A star system consisting of two stars that orbit each other due to mutual gravitational attraction.

17. Galaxy - A vast system of stars, interstellar gas, dust, and dark matter held together by gravity; the universe contains billions of galaxies.

18. Spiral Galaxy - A galaxy with a rotating disk structure, spiral arms, and a central bulge; these galaxies often contain younger stars and active star formation.

19. Elliptical Galaxy - A type of galaxy characterized by an oval or spherical shape with little gas and dust, consisting mainly of older stars.

20. Irregular Galaxy - A galaxy with no defined shape, often rich in gas and dust, and exhibiting high rates of star formation.

21. Hubble’s Tuning Fork - A classification system developed by Edwin Hubble that categorizes galaxies based on their shape, including elliptical, spiral, and barred spiral galaxies.

22. Barred Spiral Galaxy - A type of spiral galaxy featuring a central elongated bar structure of stars, with spiral arms extending from the ends of the bar.

23. Milky Way - The barred spiral galaxy that contains our solar system; it consists of billions of stars, dust, and gas and has a supermassive black hole at its center.

24. Pleiades - An open star cluster in the constellation Taurus, consisting of hot, young stars that are relatively close to Earth.

25. Globular Cluster - A dense, spherical collection of old stars, gravitationally bound and orbiting the central region of a galaxy.

Key Topics and Concepts with Explanations

1. Causes of Moon Phases - The Moon’s phases result from its orbit around Earth and how sunlight reflects off its surface. Different angles between the Earth, Moon, and Sun create different visible shapes.

2. Lunar and Solar Eclipses - A lunar eclipse happens when Earth blocks sunlight from reaching the Moon. A solar eclipse occurs when the Moon blocks sunlight from reaching Earth.

3. The Moon's Orbital Tilt - The Moon’s orbit is tilted about 5 degrees relative to Earth's orbit, preventing monthly eclipses.

4. Types of Lunar Eclipses - These include penumbral (Moon passes through Earth’s outer shadow), partial (partially obscured by Earth's shadow), and total (fully covered in Earth’s shadow, appearing red).

5. Types of Solar Eclipses - Total (Moon fully covers the Sun), annular (Moon appears smaller, leaving a ring), and partial (Moon covers only part of the Sun).

6. Effect of Distance on Gravitational Force - Gravitational force decreases with the square of the distance between objects; doubling the distance reduces the force to one-fourth.

7. Universal Gravitation Formula - The equation F = G(m1m2/r^2) explains that gravitational force is proportional to mass and inversely proportional to distance squared.

8. The Sun’s Core and Energy Production - The Sun’s core is the site of nuclear fusion, where hydrogen atoms combine to form helium, releasing vast amounts of energy.

9. Solar Wind and its Impact on Earth - The solar wind is composed of charged particles that cause auroras and can disrupt communications and power grids on Earth.

10. The Sun's Life Cycle and Future Evolution - The Sun will eventually expand into a red giant before shedding its outer layers and collapsing into a white dwarf.

11. Solar Phenomena (Solar Prominences, Coronal Mass Ejections) - Solar prominences are large loops of plasma extending from the Sun's surface, while coronal mass ejections (CMEs) are bursts of charged particles that can impact Earth's magnetic field.

12. The Solar Cycle and its Duration - An 11-year cycle in which the Sun's activity, including sunspots and solar flares, fluctuates.

13. Effects of Solar Wind on Earth - Causes phenomena like auroras and can interfere with satellites and power grids.

14. The Structure of the Sun - The Sun has several layers: the core (energy production), radiative and convection zones (energy transfer), photosphere (visible surface), chromosphere, and corona (outer atmosphere).

15. The Concept of Star Systems - A star system consists of two or more stars orbiting each other due to gravitational attraction.

16. Binary and Multiple-Star Systems - Most stars exist in binary or multiple-star systems rather than alone.

17. The Pleiades and Other Star Clusters - The Pleiades is an open cluster of young stars.

18. Differences Between Open and Globular Clusters - Open clusters are younger and loosely bound, while globular clusters are older and densely packed.

19. Spiral vs. Elliptical vs. Irregular Galaxies - Spiral galaxies have structured arms, elliptical galaxies are oval-shaped with older stars, and irregular galaxies have no defined shape and contain young stars.

20. Hubble’s Tuning Fork and Galaxy Classification - A diagram used to classify galaxies based on their shapes, such as elliptical, spiral, and barred spiral galaxies.