EAPS 105: Vocabulary Definitions from Homework 3

3.1. In Wikipedia, look up "Mercury (planet)" and answer this question: What is unusual about the length of Mercury's day?

A) Its day is shorter than any other planet.

B) Its day lasts forever on the side facing the Sun because it is tidally locked.

C) Its day is longer than its year.

D) Its day is exactly the same length as Earth's despite it being much closer to the Sun.

C) Its day is longer than its year.

3.2. In Wikipedia, look up "Venus" and answer this question: What is unusual about Venus' rotation compared to most other planets?

A) It does not rotate at all

B) It rotates backwards

C) It rotates faster than any other planet

B) It rotates backwards

3.3. In Wikipedia, look up "Uranus" and answer this question: What is unusual about Uranus' axis of rotation compared to most other planets?

A) Uranus' axis of rotation is sideways, almost parallel to the plane of the Solar System.

B) Uranus' axis of rotation is at an angle of about 45 degrees relative to the plane of the Solar System.

C) Uranus' axis of rotation is almost perpendicular to the plane of the Solar System.

D) Uranus' axis of rotation constantly changes each year.

A) Uranus' axis of rotation is sideways, almost parallel to the plane of the Solar System.

3.4. In Wikipedia, look up "tide" and answer this question: There is a figure showing a schematic of only the lunar portion of Earth's tides. How many high tides form at the same time and where are they located?

A) Only one high tide forms and it is on the side closest to the Moon.

B) Only one high tide forms and it is on the side farthest from the Moon.

C) Two high tides forms and they are on the sides closest and farthest from the Moon.

D) Two high tides forms and they are on the sides that are not closest or farthest from the Moon

C) Two high tides forms and they are on the sides closest and farthest from the Moon.

3.5. In Wikipedia, look up "tide" and answer this question: Just under the schematic figure from question 3.4 there is another figure showing the axis of the tidal bulge relative to the position of the Moon. How is the axis of the bulge closest to the Moon oriented relative to the position of the Moon?

A) It is aligned with it.

B) It has been dragged ahead (upwards) of the position directly under the Moon.

C) It lags behind (downwards) the position directly under the Moon.

B) It has been dragged ahead (upwards) of the position directly under the Moon.

3.6. In Wikipedia, look up "Tidal locking" and answer this question: Which of the following are characteristics of a tidally locked astronomical body (don't worry about exceptions)?

A) It rotates about its axis at the same time it takes to orbit its parent body.

B) It always has the same face toward the object it is orbiting.

C) Usually, only the satellite is tidally locked to the larger body

D) All the above

D) All the above

3.7. In Wikipedia, look up "History of Astronomy", read the intro and then scroll down to "Greece and Hellenistic world", and answer this question: What were the first three-dimensional models to explain the apparent motion of the planets based on?

A) The belief that the universe revolved around the Center of the Milky Way.

B) The belief that the universe revolved around the Sun.

C) The belief that the universe revolved around the Earth.

D) The belief that the universe had no motion.

C) The belief that the universe revolved around the Earth.

3.8. In Wikipedia, look up "Nicolaus Copernicus" and answer this question: What was Copernicus' revolutionary contribution to planetary science?

A) He determined that planets orbit in ellipses.

B) He determined that the Sun was at the center of the universe rather than the Earth.

C) He determined the size and distance to the Sun.

D) He discovered Neptune.

B) He determined that the Sun was at the center of the universe rather than the Earth.

3.9. In Wikipedia, look up "Kepler's laws of planetary motion" and answer this question: Which of the following is not one of Kepler's three laws?

A) The orbit of a planet is an ellipse with the Sun at one of the two foci.

B) A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time.

C) The square of a planet's orbital period is proportional to the cube of the length of the semi-major axis of its orbit.

D) A planet will always spin in the same direction it orbits.

D) A planet will always spin in the same direction it orbits.

3.10. In Wikipedia, look up "Ellipse" and answer this question: The shape of an ellipse can range from a circle to infinite elongation. This is noted by its eccentricity. An eccentricity of 0 is a circle. What is the eccentricity of an infinitely long ellipse?

A) the infinity symbol

B) 1

C) 100

D) 90 degrees

B) 1

3.11. In Wikipedia, look up "Neptune" and answer this question: How was Neptune discovered?

A) By an amateur astronomer looking for comets.

B) By the ancient Greeks with the first telescope ever created.

C) y a young astronomer who systematically imaged the night sky in pairs of photographs, then examine each pair to determine whether any objects had shifted position.

D) Its location was predicted mathematically based on unexpected changes in the orbit of Uranus.

D) Its location was predicted mathematically based on unexpected changes in the orbit of Uranus.

3.12. In Wikipedia, look up "Centrifugal force" and answer this question: A centrifugal force is an inertial force created by rotating an object around a central point. This force serves to make the object fly outwards away from the point it is rotating about, the opposite direction that gravity is pulling on an orbiting moon or satellite. Which of the following factors influences the magnitude of the centrifugal force?

A) The mass of the object

B) The angular velocity of the object

C) The distance the object it from the point of rotation

D) All the above

D) All the above

3.13. In Wikipedia, look up "Orbit", read the intro and then scroll down to "Understanding orbits", and answer this question: As a smaller object (like a moon or satellite) is pulled by gravity toward a more massive object (like a planet), it falls toward that body. Under what circumstances will the smaller object not crash into the more massive object?

A) If the smaller object has mass that is very close to that of the more massive object.

B) If the massive object is also moving.

C) If the smaller object has enough tangential velocity (i.e., velocity in a direction perpendicular to the direction of the more massive body).

D) If the smaller object has an even smaller object orbiting it.

C) If the smaller object has enough tangential velocity (i.e., velocity in a direction perpendicular to the direction of the more massive body).

3.14. In Wikipedia, look up "Escape velocity" and answer this question: Which of the following does the escape velocity (speed) of a planet not depend on?

A) The mass of the planet

B) The distance from the center of spherically symmetric primary body

C) The universal gravitational constant

D) The escape velocity of a planet depends on all the above

D) The escape velocity of a planet depends on all the above

3.15. In Wikipedia, look up "ʻOumuamua" (note there is a single quote at the beginning of the name, which is actually a Hawaiian 'okina) and answer this question: ʻOumuamua is the first known interstellar object detected passing through the Solar System. How do we know this object is not from our Solar System?

A) Because it has a hyperbolic trajectory relative to the Sun and thus exceeds the Sun's escape velocity.

B) Because it has characteristics different than any known objects in our Solar System.

C) Because it approached the inner Solar System from the direction of Vega in the constellation Lyra

D) Because it is actually an alien spacecraft.

A) Because it has a hyperbolic trajectory relative to the Sun and thus exceeds the Sun's escape velocity.

3.16. In Wikipedia, look up "Orbital period" and answer this question: What is an orbital period?

A) The time in which the planets came into existence and began to orbit.

B) The time before an orbiting object crashes into its primary body.

C) The time a given astronomical object takes to complete one orbit around another object.

D) The angular velocity of an orbiting object.

C) The time a given astronomical object takes to complete one orbit around another object.

3.17. In Wikipedia, look up "Orbital resonance" and answer this question: What is orbital resonance?

A) When a body spins at the same rate that it orbits causing the body to deform and heat up.

B) When orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers.

C) When the time it takes an object to orbit (its period) changes periodically because of tidal forces.

D) When the migration of a giant planet influences the orbits of smaller bodies.

B) When orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers.

3.18. In Wikipedia, look up "Pluto", read the intro and then scroll down to "Relationship with Neptune", and answer this question: Pluto periodically comes closer to the Sun than Neptune, but they will never collide. Why is that?

A) Pluto and Neptune are in a stable orbital resonance that prevents them from ever getting close.

B) Pluto orbits at an angle to the plane of the Solar System.

C) These bodies are too small in the vastness of space to ever actually hit each other.

D) Their orbits do not actually cross — Neptune is always closer to the Sun.

A) Pluto and Neptune are in a stable orbital resonance that prevents them from ever getting close.

3.19. In Wikipedia, look up "Grand tack hypothesis" and answer this question: The Grand tack hypothesis proposes that Jupiter formed at 3.5 AU, then migrated inward to 1.5 AU, before reversing course due to capturing Saturn in an orbital resonance, eventually halting near its current orbit at 5.2 AU. Which of the following does the Grand Tack Hypothesis not attempt to explain?

A) Why Mars is smaller than expected based on the location of its orbit.

B) Why the asteroid belt is only a remnant of the population it likely had before Jupiter moved into the inner solar system.

C) Why Mercury has a core much larger than the other terrestrial planets.

D) Why there are not more planets bigger than Earth (super-Earths) in the inner solar system.

C) Why Mercury has a core much larger than the other terrestrial planets.

3.20. In Wikipedia, look up "Gliese 710" and answer this question: Which of the following is true about this star?

A) It is projected to pass near our Solar System in ~1.3 million years.

B) It will be as bright in our night sky as the brightest planets.

C) It has the potential to perturb the Oort cloud in the outer Solar System, send showers of comets into the inner Solar System for millions of years, triggering visibility of about ten naked-eye comets per year, and possibly causing an impact event.

D) All the above

D) All the above