Chapter 2 - Lecture 1-PV

C) By locating the Southern Cross

Explanation: In the southern hemisphere, the Southern Cross constellation is a prominent feature that helps observers find the celestial pole, as it points towards the South Celestial Pole.

C) It rises before sunset

Explanation: After one Sidereal day, the star Aquarius rises before sunset, indicating the cyclical nature of star visibility in relation to the Earth's rotation.

C) Once a day

Explanation: The stars appear to move around the Earth once a day, creating the illusion of daily motion in the night sky, similar to the movement of the Sun.

C) The apparent size of an object as seen from Earth

Explanation: Angular size refers to how large an object appears in the sky from our perspective, which is measured in angles.

C) Ecliptic Plane and Galactic Plane

Explanation: The question specifically addresses the angular relationship between the Ecliptic Plane and the Galactic Plane, which are fundamental concepts in astronomy.

B) 88

Explanation: There are a total of 88 constellations that fill the entire sky, providing a framework for identifying various regions.

B) By its altitude and direction

Explanation: The position of an object in the local sky can be specified by its altitude above the horizon and its direction along the horizon, which are key concepts in observational astronomy.

B) Light and air pollution

Explanation: The text highlights that light and air pollution in Hong Kong make it very difficult to see all the stars, emphasizing the impact of urbanization on astronomical observations.

B) Light and air pollution

Explanation: The text indicates that light and air pollution are significant factors that hinder the visibility of stars in urban areas, particularly in places like Hong Kong.

C) Polaris

Explanation: The North Star is commonly referred to as Polaris, which is significant for navigation and astronomy due to its position in the sky.

B) An imaginary sphere

Explanation: The celestial sphere is described as an imaginary sphere, which helps in visualizing celestial objects with Earth at its center.

A) Zenith, horizon, and meridian

Explanation: The local sky consists of the zenith (the point directly overhead), the horizon (the line where the sky meets the ground), and the meridian (the half-circle that runs from the North horizon to the South horizon).

C) Local North-South

Explanation: The celestial sphere should be oriented in the local North-South direction to accurately represent the position of stars and celestial objects as observed from a specific location on Earth.

B) Ursa Major

Explanation: The Big Dipper is an asterism that is part of the constellation Ursa Major, which is one of the most recognizable patterns in the night sky.

B) By finding Polaris, the North Star

Explanation: In the northern hemisphere, the celestial pole can be found by locating Polaris, which is positioned nearly directly above the North Pole and serves as a reliable guide for navigation.

C) It varies with latitude

Explanation: The sky's appearance and the direction of zeniths change with different latitudes, indicating that geographical position affects celestial observations.

C) It determines the Sun's position in the sky

Explanation: The time of year influences the Sun's position in the sky, which in turn affects which constellations are visible at night, as the Sun's light can obscure certain stars.

B) Due to the tilt of the Earth's axis and its orbit around the sun

Explanation: The constellations visible from Earth change with latitude and time of year due to the tilt of the Earth's axis and its orbit around the sun, which affects our perspective of the night sky.

C) Flat spiral galaxy

Explanation: The Milky Way is classified as a flat spiral galaxy, which describes its structure and the arrangement of its stars and other components.

D) 1°

Explanation: The Earth moves approximately 1° in one solar day, which is calculated as 360° divided by 365 days, indicating the Earth's rotation relative to the Sun.

B) The time between two sunsets

Explanation: A Solar Day is defined by the time between two sunsets, which helps in understanding the daily cycle of celestial objects, including stars.

B) 88

Explanation: There are 88 officially recognized constellations that cover the celestial sphere, providing a framework for identifying and categorizing stars and celestial objects.

C) To specify locations on Earth

Explanation: The Degrees, Minutes, and Seconds system is primarily used in navigation and cartography to specify precise locations on the Earth's surface, aiding in accurate positioning.

C) 90°

Explanation: At the North Pole, the North Celestial Pole is directly overhead, making an angle of 90° with the horizon.

C) Its billions of stars

Explanation: The presence of billions of stars in the Milky Way makes it a delight to see, as it creates a stunning visual display in the night sky.

C) They rise and set

Explanation: Just like the Sun, stars rise and set in the sky, which is a fundamental aspect of their apparent motion as observed from Earth.

C) A vast expanse filled with stars and celestial objects

Explanation: From Earth, the universe appears as a vast expanse filled with stars, planets, and other celestial objects, creating a rich tapestry of patterns in the night sky.

B) Earth rotates from west to east

Explanation: Stars appear to rise and set due to the rotation of the Earth from west to east, which causes them to appear to circle the sky from east to west.

B) The Milky Way

Explanation: The Milky Way is specifically mentioned as a prominent feature that can be observed from Earth, indicating its significance in the night sky.

B) Because of Earth's rotation

Explanation: Stars appear to rise and set due to the rotation of the Earth, which creates the illusion of movement in the night sky.

B) To depict stars as fixed points in the sky

Explanation: The celestial sphere model is designed to represent stars as fixed points on a sphere surrounding the Earth, allowing for a simplified view of the night sky.

C) Black holes

Explanation: The outline lists topics such as Constellations, Celestial Sphere, Local Sky, and Zodiac, but does not mention black holes, making it the correct choice.

C) Billions of stars

Explanation: The Milky Way is composed of billions of stars, which contributes to its visibility and beauty in the night sky.

B) It rotates about the celestial pole axis once a day

Explanation: The celestial sphere appears to rotate about the celestial pole axis once a day due to the Earth's rotation, giving the illusion of movement in the sky.

C) Half of it

Explanation: At any given time, you can see at most half of the Celestial Sphere from a specific location, as the other half is below the horizon.

D) Northern Hemisphere

Explanation: The North Celestial Pole is located in the Northern Hemisphere, serving as a reference point for celestial navigation and observation.

C) Your latitude

Explanation: Your latitude affects which constellations are visible because it determines which parts of the sky are obscured by the Earth, influencing the constellations you can see.

C) The Sun's apparent path through the Zodiac

Explanation: The ecliptic refers to the Sun's apparent path through the Zodiac, marking the plane in which the Earth orbits the Sun and the positions of the zodiacal constellations.

C) Over 2,000

Explanation: It is stated that we can see over 2,000 stars with the naked eye from Earth, highlighting the visibility of celestial objects in our local sky.

B) 88

Explanation: The text mentions that each position in the sky belongs to one of 88 constellations, indicating the standardized number of constellations recognized in astronomy.

B) Degrees

Explanation: The Degrees, Minutes, and Seconds system primarily uses degrees as the main unit of measurement for angles, where each degree can be subdivided into minutes and seconds.

A) 60

Explanation: In the Degrees, Minutes, and Seconds system, one degree is divided into 60 minutes, which is a standard subdivision of angular measurement.

B) 60

Explanation: Each minute in the Degrees, Minutes, and Seconds system is further divided into 60 seconds, maintaining a consistent subdivision for precise angle measurement.

B) It is a new zodiac sign

Explanation: Ophiuchus is recognized as a new zodiac sign due to the precession of the Earth's axis, which has introduced 13 constellations within the Zodiac, placing Ophiuchus between Sagittarius and Scorpio.

B) 90° - φ

Explanation: The celestial equator makes an angle of 90° - φ with the horizon at latitude φ, which reflects the relationship between the observer's latitude and the position of the celestial equator.

C) They are considered 'moving stars'

Explanation: The Sun, Moon, and planets are referred to as 'moving stars' because they do not remain fixed on the celestial sphere; instead, they move relative to the background of fixed stars.

C) Between Sagittarius and Scorpio

Explanation: Ophiuchus is positioned between Sagittarius and Scorpio in the Zodiac, marking its significance in astrological interpretations.

B) The sky visible from a specific location on Earth

Explanation: The 'Local Sky' refers to the portion of the sky that is visible from a specific location on Earth, emphasizing the personal perspective in astronomical observations.

B) A solar day is longer than a sidereal day

Explanation: A solar day is approximately 24 hours, while a sidereal day is about 23 hours and 56 minutes, making the solar day longer due to the additional rotation needed to align with the Sun.

C) To measure temperature

Explanation: Angles are specifically used to denote position and apparent size in the sky, not for measuring temperature.

A) Due to the rotation of the Earth

Explanation: Stars appear to rise and set because of the rotation of the Earth on its axis, which causes different stars to become visible at different times throughout the night.

B) Our view into the plane of our galaxy

Explanation: The band of light that we see as the Milky Way is essentially our perspective looking into the plane of our galaxy, showcasing the stars and cosmic material within it.

B) It causes them to rise and set

Explanation: The rotation of the Earth creates the effect of stars rising in the east and setting in the west, which is a fundamental aspect of celestial motion as observed from the Earth's surface.

B) As landmarks to identify regions of the sky

Explanation: Modern astronomers utilize constellations as landmarks to identify specific regions of the sky, such as stating that the Moon is currently in the constellation of Orion.

D) Polaris

Explanation: The rotation axis of the celestial sphere is adjusted towards Polaris, the North Star, which serves as a reference point for navigation and orientation in the northern hemisphere.

B) 1°

Explanation: After one sidereal day, the Earth needs to rotate an additional 1° to align with the noon position of the Sun, which reflects the difference between solar and sidereal time.

B) The Sun’s apparent path through the celestial sphere

Explanation: The ecliptic refers to the Sun's apparent path through the celestial sphere over the course of a year, which is crucial for understanding the movement of celestial bodies.

C) Your latitude

Explanation: The altitude of the north celestial pole is equivalent to your latitude, which is a key concept in celestial navigation and understanding the position of stars.

B) A new birth dates – constellation relationship

Explanation: The introduction of Ophiuchus necessitates a reevaluation of the relationship between birth dates and constellations, as it alters the traditional zodiac framework.

E) Atlantis

Explanation: Atlantis is not one of the 88 official constellations; the other options are all recognized constellations in the celestial sphere.

C) East

Explanation: In the Northern Hemisphere, stars generally rise in the eastern part of the sky, which is a consistent pattern observed across various locations.

C) They set in the West

Explanation: In both the Northern and Southern Hemispheres, stars set in the western part of the sky, maintaining a similar pattern despite differences in their rising directions.

B) Click to play the movie or open it with your own media player

Explanation: The instruction clearly states to either click to play the movie or open the file with a personal media player, indicating the method for viewing the content.

B) Position

Explanation: Angles are used to denote the position of celestial objects in the sky, allowing astronomers to locate them accurately.

C) 60.2 degrees

Explanation: The Ecliptic Plane and the Galactic Plane are offset by approximately 60.2 degrees, indicating a significant angular relationship between these two important astronomical planes.

B) A band of light that makes a circle around the celestial sphere

Explanation: The Milky Way appears as a band of light stretching across the night sky, representing our view into the plane of our galaxy, which encircles the celestial sphere.

B) It determines which constellations remain below the horizon

Explanation: Your position on Earth, defined by latitude, influences which constellations are visible in the night sky, as some will remain below the horizon depending on your location.

B) Orion (The Hunter)

Explanation: Orion, also known as The Hunter, is one of the most recognized constellations and serves as a landmark in the sky.

C) About halfway between the center and outer edge

Explanation: Recent claims suggest that our solar system is located approximately halfway between the center and the outer edge of the Milky Way galaxy.

B) 23 hours 56 minutes

Explanation: A sidereal day is approximately 23 hours and 56 minutes long, which accounts for the Earth's rotation relative to distant stars rather than the Sun.

B) 4 minutes

Explanation: Stars rise approximately 4 minutes earlier each evening, which is a key concept in understanding their motion relative to the Earth.

B) Sidereal Day

Explanation: The Sidereal Day is the concept that relates to the apparent movement of stars and celestial objects, as it measures the time it takes for the Earth to rotate once relative to the stars.

C) Cartesian coordinate system

Explanation: ECEF is a Cartesian coordinate system that provides a three-dimensional representation of points on the Earth's surface based on its center.

B) A representation of the stars and constellations

Explanation: The celestial sphere is a conceptual model that represents the positions of stars and constellations in the sky, helping astronomers and stargazers visualize the night sky.

B) It allows for navigation and orientation

Explanation: Knowing your latitude in relation to Polaris is crucial for navigation, as Polaris serves as a fixed point in the sky that helps travelers orient themselves in the northern hemisphere.

D) Northern Hemisphere

Explanation: The content specifies that the observations regarding the motion of stars are as seen in the northern hemisphere, indicating a geographical context for the described phenomena.

C) The Sun moves eastward along the ecliptic

Explanation: As the Earth orbits the Sun, the Sun appears to move eastward along the ecliptic, which is the apparent path of the Sun across the sky throughout the year.

B) Because of Earth's orbital motion

Explanation: The Earth's orbital motion around the Sun alters the apparent position of stars in the sky, leading to different constellations being visible at different times of the year.

B) The point on the celestial sphere directly overhead

Explanation: The zenith is the point on the celestial sphere that is directly overhead an observer, representing the highest point in the sky from their perspective.

B) The point on the celestial sphere directly underneath

Explanation: The nadir is the point on the celestial sphere that is directly underneath an observer, and it is not visible from their position.

C) 45.5042

Explanation: To convert 45 degrees, 30 minutes, and 15 seconds to decimal degrees, you calculate: 45 + (30/60) + (15/3600) = 45.5042.

B) The projection of Earth's north pole onto the celestial sphere

Explanation: The North Celestial Pole is defined as the projection of Earth's north pole onto the celestial sphere, serving as a key reference point for navigation and astronomy.

C) 13

Explanation: The precession of the Earth's axis has led to the recognition of 13 constellations within the Zodiac, including the newly acknowledged Ophiuchus.

B) It is the Prime Meridian with 0 degrees longitude

Explanation: The Greenwich Meridian Line is recognized as the Prime Meridian, which is defined as 0 degrees longitude, serving as the reference point for measuring longitude across the globe.

B) 1 degree

Explanation: Stars advance their positions by 1 degree per night, which is important for tracking their movement in the night sky.

C) The zenith varies with latitude

Explanation: The zenith, or the point directly overhead, changes with latitude, as it is dependent on the observer's position on Earth.

B) 1673

Explanation: The celestial sphere model was constructed in Beijing in the year 1673, marking an important development in the understanding of celestial navigation and astronomy.

C) Precession of the Earth's axis

Explanation: The precession of the Earth's axis is the astronomical phenomenon responsible for the inclusion of Ophiuchus in the Zodiac, changing the traditional understanding of zodiac signs.

C) It makes the object appear smaller

Explanation: An object's angular size appears smaller as it is farther away, which is a fundamental concept in understanding how we perceive the size of distant objects.

B) They point to different directions

Explanation: Different latitudes result in zeniths pointing to different directions, which is a key concept in understanding how celestial observations vary across the globe.

D) It helps in understanding the structure of the Milky Way

Explanation: The angular offset between the Ecliptic Plane and the Galactic Plane is significant for understanding the structure and dynamics of the Milky Way galaxy, as it provides insights into the orientation of our solar system within the galaxy.

B) It varies with the seasons

Explanation: The sky varies as the Earth orbits the Sun, leading to changes in the position of celestial objects and the appearance of different constellations throughout the seasons.

B) East to West

Explanation: As the Earth rotates from west to east, stars appear to move across the sky from east to west, creating the illusion of rising and setting.

B) Ancient people's imagination

Explanation: Most official constellation names are derived from the imagination of ancient peoples, particularly in Western cultures, reflecting their interpretations of the night sky.

B) Discovering the Universe for Yourself

Explanation: Chapter 2 is titled 'Discovering the Universe for Yourself,' indicating that it focuses on understanding astronomical concepts through personal exploration and observation.

B) To visualize the positions of objects in the sky

Explanation: The celestial sphere is a model that helps us visualize where objects like stars, planets, and the Moon are located in the sky from our perspective on Earth.

B) The projection of Earth's south pole onto the celestial sphere

Explanation: The South Celestial Pole is the projection of Earth's south pole onto the celestial sphere, providing a reference point for observations in the southern hemisphere.

B) Straddle both Eastern and Western Hemispheres

Explanation: At the Greenwich Meridian Line, one can physically stand and straddle both the Eastern and Western Hemispheres, highlighting its unique geographical position.

B) The rotation of the Earth

Explanation: The apparent movement of the Sun, Moon, and planets on the celestial sphere is caused by the rotation of the Earth, which makes these celestial objects seem to move from one position to another.

B) Angular Size = 2π × Physical Size / 360

Explanation: The formula for calculating angular size involves multiplying the physical size of an object by 2π and dividing by 360, which relates to the concept of angular measurement in degrees.

B) On the horizon plane

Explanation: Directions North, South, East, and West (NSEW) are measured on the horizon plane, which is a flat plane that includes the zenith as the normal.

B) They all lie at about the same distance from Earth

Explanation: A common misconception is that the brightest stars in a constellation lie at about the same distance from Earth, but in reality, they can be quite far apart.

B) They have the same zenith direction but at different times

Explanation: At the same latitude, different longitudes will have the same zenith direction, but the timing of when that zenith is observed will differ, illustrating the relationship between time and position on Earth.

B) They are blocked by the Earth

Explanation: Some constellations are hidden from view because they are obstructed by the Earth itself, depending on your location and the time of year.

B) A region of the sky

Explanation: A constellation is defined as a specific region of the sky, and there are 88 recognized constellations that fill the entire sky.

B) More than 2,000

Explanation: It is stated that with the naked eye, we can see more than 2,000 stars from Earth, highlighting the visibility of celestial objects under optimal conditions.

C) Stars are visible only at night, looking away from the Sun

Explanation: Stars can only be seen at night when we are looking away from the Sun, as the Sun's brightness obscures them during the day.

B) The projection of Earth's equator onto the celestial sphere

Explanation: The celestial equator is defined as the projection of Earth's equator onto the celestial sphere, serving as a fundamental reference point in celestial navigation.

B) φ

Explanation: At a latitude φ in the Northern Hemisphere, the North Celestial Pole is positioned at an angle φ with respect to the horizon, indicating the observer's latitude.

C) In any direction into the galactic plane

Explanation: We can observe the Milky Way when looking in any direction into the galactic plane, which allows us to see its structure and composition.

A) Earth-Centered, Earth-Fixed

Explanation: ECEF stands for Earth-Centered, Earth-Fixed, which refers to a Cartesian coordinate system used to represent positions on the Earth's surface relative to its center.

B) It is equal to your latitude

Explanation: The altitude of the North Star (Polaris) corresponds directly to your latitude, meaning that if you know your latitude, you can determine the altitude of Polaris in the sky.

B) 4 minutes

Explanation: It takes approximately 4 minutes for the Earth to rotate 1°, which is derived from the calculation of 24 hours multiplied by 60 minutes divided by 360 degrees.

B) The self-rotation of the Earth

Explanation: The daily cycle of sunrise and sunset is caused by the self-rotation of the Earth on its axis, which creates the appearance of the Sun moving across the sky.

C) At the Royal Observatory, Greenwich

Explanation: The Prime Meridian is marked at the Royal Observatory in Greenwich, which is a significant historical site for navigation and timekeeping.

C) The Earth

Explanation: The celestial sphere is modeled with the Earth at its center, allowing us to visualize the positions of celestial objects relative to our planet.

A) Distance from the equator and distance from the prime meridian

Explanation: Latitude measures the distance north or south of the equator, while longitude measures the distance east or west of the prime meridian, together defining a specific location on the Earth's surface.

B) A half-circle from the North horizon to the South horizon

Explanation: The meridian is defined as the half-circle that extends from the North horizon, through the zenith, to the South horizon, serving as a reference for measuring celestial positions.

B) The altitude of the north celestial pole

Explanation: In the context provided, 'a' represents the altitude of the north celestial pole, which is directly related to your latitude and the position of Polaris.

D) To mark the boundary between hemispheres

Explanation: The markings of the Prime Meridian at the Royal Observatory indicate the boundary between the Eastern and Western Hemispheres, which is crucial for navigation and geography.

B) The middle of the Zodiac

Explanation: The ecliptic line runs exactly along the middle of the Zodiac, serving as a reference for the positions of celestial bodies in relation to the Earth's orbit.

C) The time between two occurrences of the same position of the Sun

Explanation: A solar day is defined as the time between two occurrences of the same position of the Sun, such as between two noons, and is equal to 24 hours.

C) The time between two occurrences of the same position of a star

Explanation: A sidereal day is defined as the time between two occurrences of the same position of a star, which reflects the Earth's rotation relative to distant stars.

C) Eastward

Explanation: The Sun appears to move eastward across the sky during the day due to the rotation of the Earth from west to east, which creates the illusion of the Sun rising in the east and setting in the west.

B) It represents the path of the sun through the sky

Explanation: The Zodiac is significant in astronomy as it represents the path that the sun appears to take through the sky over the course of a year, marking the positions of various constellations.

C) 0 degrees

Explanation: The Prime Meridian is defined as 0 degrees longitude, serving as the starting point for measuring longitude around the world.

C) It can change the amount of the Celestial Sphere visible

Explanation: Atmospheric refraction can affect how much of the Celestial Sphere is visible from a given location, potentially allowing observers to see slightly more than half under certain conditions.

C) It appears smaller

Explanation: As an object moves farther away, its perceived size decreases, making it appear smaller to the observer, which is a key principle in visual perception.

C) The same stars are visible in both Hemispheres

Explanation: While the same stars can be visible in both Hemispheres, their positions and paths across the sky differ due to the observer's location, affecting how and when they are seen.

A) The point where the sky meets the ground

Explanation: The horizon is the boundary line where the sky appears to meet the ground, marking the limits of what can be observed from a specific location on Earth.

C) East

Explanation: The Sun typically rises in the east, which is a fundamental aspect of its eastward movement across the sky, influenced by the Earth's rotation.

B) The Sun's illumination of the Moon

Explanation: The phases of the Moon are caused by the Moon's orbit around the Earth and the way the Sun illuminates it, leading to different visible portions from Earth.

B) They help in identifying and categorizing stars

Explanation: Constellations serve as a system for identifying and categorizing stars and celestial objects, making it easier for astronomers and enthusiasts to locate and study them.

B) A narrow strip of the sky where the Moon and planets are visible

Explanation: The Zodiac refers to a narrow strip in the sky where the Moon and planets are typically found, as they stay relatively close to the ecliptic line.

B) The orbit of the Moon around the Earth

Explanation: A month is defined by the orbit of the Moon around the Earth, which results in the various phases of the Moon that we observe.

B) East and west

Explanation: All other stars, along with the Sun, Moon, and planets, follow a consistent pattern of rising in the east and setting in the west, which is a fundamental aspect of celestial motion.

B) The plane that divides the Earth into northern and southern hemispheres

Explanation: The celestial equatorial plane is an imaginary plane that extends from Earth's equator into space, effectively dividing the celestial sphere into northern and southern hemispheres.

A) Aquarius rises at sunset

Explanation: Initially, Aquarius rises at sunset, which is a reference point for understanding its subsequent rise in relation to the Solar Day.

B) No, they may not belong to the same cluster

Explanation: The brightest stars in a constellation do not necessarily belong to the same star cluster; they can be at varying distances from Earth and may not be physically related.

C) Stars

Explanation: In the night sky, stars appear to form fixed patterns, which are often referred to as constellations, and they move across the sky due to the Earth's rotation.

B) Stars near the south celestial pole

Explanation: From a particular location on Earth, stars near the south celestial pole are not visible, limiting our local view of the night sky.

D) The ecliptic is the plane of Earth's orbit

Explanation: The ecliptic represents the plane of Earth's orbit around the Sun, and the Moon and planets move in orbits that do not differ greatly from this plane.

C) It influences the seasons

Explanation: The Earth's axial tilt is significant because it influences the seasons by affecting how sunlight is distributed across the planet throughout the year.

B) The Earth's rotation

Explanation: The apparent eastward movement of the Sun is caused by the Earth's rotation on its axis from west to east, leading to the daily cycle of sunrise and sunset.

C) It indicates the distance from the equator

Explanation: Latitude is crucial in navigation as it indicates how far a location is from the equator, which is essential for determining geographic positions and navigation routes.

C) The tilt of the Earth's rotation axis

Explanation: The changing seasons are primarily due to the tilt of the Earth's rotation axis as it orbits around the Sun, affecting the angle and intensity of sunlight received.

B) For angles less than a few degrees

Explanation: The statement specifies that the formula for angular size is most accurate for small angles, particularly those less than a few degrees, which is important for precise measurements in astronomy.

B) Obliquity

Explanation: The axial tilt of the Earth is referred to as obliquity, which is approximately 23.5 degrees and plays a crucial role in the changing seasons.

B) 24 hours

Explanation: A solar day is equal to 24 hours, which is the standard time measurement for a full rotation of the Earth relative to the Sun.

C) Distant stars

Explanation: A sidereal day is measured using distant stars as a reference point, indicating the time it takes for the Earth to complete one full rotation around its axis relative to those stars.

E) It remains constant throughout the year

Explanation: The Sun's eastward movement remains relatively constant throughout the year, although its rising and setting points shift slightly with the seasons due to the tilt of the Earth's axis.

C) It measures distance from the prime meridian

Explanation: Longitude measures the distance east or west of the prime meridian, which is essential for pinpointing locations on the Earth's surface.

B) They never set

Explanation: Circumpolar stars are defined by their position near the north celestial pole, allowing them to remain visible throughout the night as they never set below the horizon.

B) Their positions can be misleading

Explanation: The phrase 'Seeing Is Not Believing' suggests that while stars may appear close together in a constellation, they can actually be at very different distances from Earth, making their positions misleading.

B) Ecliptic plane and celestial equatorial plane

Explanation: The two main planes in relation to axial tilt are the ecliptic plane, which is the plane of Earth's orbit around the Sun, and the celestial equatorial plane, which is an extension of Earth's equator into space.

B) Stars rise in the East in both Hemispheres

Explanation: The primary difference is not in the rising direction itself, as stars rise in the East in both the Northern and Southern Hemispheres, but rather in their overall path across the sky.

B) They have different orbital planes

Explanation: The Moon and planets do not lie exactly on the ecliptic because their orbital planes differ slightly from that of Earth's orbit, causing them to be positioned within several degrees of the ecliptic.

B) It is a circumpolar star

Explanation: The North Star (Polaris) is a circumpolar star, meaning it is located near the north celestial pole and remains visible throughout the night without setting.

B) It indicates the time of day

Explanation: The eastward movement of the Sun is crucial for timekeeping, as it helps people determine the time of day based on the position of the Sun in the sky.

C) It alters the time of rising and setting

Explanation: Latitude affects the timing of when stars rise and set, as different latitudes experience varying lengths of day and night throughout the year.

C) 23.5 degrees

Explanation: The Earth's axial tilt is approximately 23.5 degrees, which affects the distribution of sunlight on the planet and contributes to seasonal variations.

B) Because the Earth revolves around the Sun

Explanation: A solar day differs from a sidereal day because the Earth revolves around the Sun, which affects the timing of solar observations compared to sidereal observations.

B) They are directly proportional

Explanation: The physical size of an object directly affects its angular size; larger physical sizes result in larger angular sizes, provided the distance remains constant.

C) They are aligned in a narrow belt

Explanation: The term 'Zodiac' implies that the Moon and planets are aligned in a narrow strip or belt in the sky, which is closely associated with the ecliptic line.