Students can keep Class 8 Science Extra Questions and Class 8th Curiosity Chapter 11 Keeping Time with the Skies Important Extra Question Answer handy for quick reference during exams.
Class 8 Science Chapter 11 Keeping Time with the Skies Extra Questions
Class 8 Science Chapter 11 Extra Questions on Keeping Time with the Skies
Keeping Time with the Skies Class 8 Very Short Question Answer
Question 1.
What is the natural satellite of Earth?
Answer:
The Moon
Quarter 2.
Name the phase when the Moon is fully visible.
Answer:
Full Moon
Quarter 3.
What is the duration of one complete cycle of Moon phases?
Answer:
About 29.5 days.
Question 4.
Which phase comes after New Moon?
Answer:
Waxing Crescent
Question 5.
In which phase is the Moon not visible at all?
Answer:
New Moon
Question 6.
What shape is the Moon’s orbit?
Answer:
Elliptical
Question 7.
What is the term for the Moon appearing to shrink?
Answer:
Waning
Question 8.
Which eclipse happens when the Moon comes between the Sun and Earth?
Answer:
Solar Eclipse
Question 9.
Can the Moon be seen during the day?
Answer:
Yes, during some phases.
Question 10.
What is the visible shape of the Moon during a First Quarter?
Answer:
Half Moon (right half visible).
Keeping Time with the Skies Class 8 Short Question Answer
Question 1.
Name all eight phases of the Moon in order.
Answer:
New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, Waning Crescent.
Question 2.
Why does the Moon appear to change shape every night?
Answer:
Because as the Moon revolves around the Earth, different portions of its sunlit side are visible from Earth.
Question 3.
What causes a solar eclipse?
Answer:
A solar eclipse occurs when the Moon comes between the Sun and Earth, blocking sunlight.
Question 4.
Why do we always see the same side of the Moon?
Answer:
Because the Moon takes the same time to rotate on its axis as it does to revolve around the Earth.
Question 5.
What is a New Moon, and when does it occur?
Answer:
A New Moon occurs when the Moon is between the Earth and the Sun, and the side facing the Earth is not lit.
Question 6.
How does the Moon affect tides on Earth?
Answer:
The Moon’s gravity pulls on Earth’s oceans, causing high and low tides.
Question 7.
Describe the appearance of a Crescent Moon.
Answer:
A Crescent Moon appears as a thin curved sliver, either waxing or waning, with only a small part lit.
Keeping Time with the Skies Class 8 Long Question Answer
Quarter 1.
What is the difference between the waxing and waning phases of the Moon?
Answer:
Waxing means the Moon is growing; the lit portion is increasing. It occurs between New Moon and Full Moon. Waning means the Moon is shrinking; the lit portion is decreasing. It occurs between Full Moon and New Moon.
- Waxing phases: Waxing Crescent, First Quarter, Waxing Gibbous
- Waning phases: Waning Gibbous, Last Quarter, Waning Crescent.
Quarter 2.
Compare and contrast a Full Moon and a New Moon.
Answer:
- Full Moon: The Moon is fully visible from Earth. Earth is between the Sun and the Moon. It occurs midway in the lunar month.
- New Moon: The Moon is not visible from Earth. The Moon is between the Earth and the Sun. It marks the beginning of the lunar month.
- In both cases, the Moon is aligned with the Earth and Sun, but from opposite directions.
Quarter 3.
Explain how the Moon’s phases affect its visibility and position in the sky.
Answer:
The Moon’s position in the sky and the timing of its rise and set depend on its phase.
- New Moon rises and sets with the Sun; not visible.
- The First Quarter is visible in the afternoon and early evening.
- Full Moon rises at sunset and sets at sunrise.
- Last Quarter is visible late at night and in the morning.
- As the Moon moves through its orbit, its angle with the Earth and Sun changes, which affects how much of it we see and when.
Question 4.
What are the main differences between solar and lunar eclipses?
Answer:
| Feature | Solar Eclipse | Lunar Eclipse |
| Occurs When | The Moon comes between the Earth and the Sun. | Earth comes between the Sun and the Moon. |
| Moon Phase | New Moon | Full Moon |
| Visibility | Only from certain areas on Earth. | Visible from anywhere it’s night. |
| Frequency | Less frequent in a given place. | More frequent and longer-lasting. |
| Type of Shadow | Moon’s shadow falls on Earth. | Earth’s shadow falls on the Moon. |
Question 5.
How do shadows help explain Moon phases and eclipses?
Answer:
Phases of the Moon happen due to the changing angle of sunlight on the Moon as it orbits Earth, not Earth’s shadow.
Eclipses, however, are directly related to shadows:
- A solar eclipse occurs when the Moon’s shadow falls on Earth.
- A lunar eclipse occurs when the Earth’s shadow falls on the Moon.
Keeping Time with the Skies Class 8 Case Based Questions
Question 1.
Anita kept a Moon observation diary for a week. On Day 1, she saw a thin crescent on the right side. By Day 4, half of the Moon was visible. By Day 7, almost the full Moon was visible.
(a) Which phase did Anita observe on Day 1?
(b) What is the name of the phase on Day 4?
(c) Was the Moon waxing or waning during these days?
Answer:
(a) Waxing Crescent
(b) First Quarter
(c) Waxing
Question 2.
On a school day, students gathered to observe a solar eclipse. Teachers advised them to wear special glasses and explained that the Moon was between the Earth and the Sun at that time.
(a) What type of eclipse were the students observing?
(b) Which Moon phase is required for this eclipse to occur?
(c) Why were students told to wear special glasses?
Answer:
(a) Solar eclipse
(b) New Moon
(c) To protect their eyes from harmful sunlight
Question 3.
A group of students watched a solar eclipse with their teacher using proper eye protection.
(a) What causes a solar eclipse?
(b) Which Moon phase is required for a solar eclipse to occur?
(c) Why is it dangerous to look at a solar eclipse without protection? (NCERT Exemplar)
Answer:
(a) A solar eclipse is caused when the Moon comes between the Sun and the Earth, casting a shadow on Earth.
(b) It happens only during a New Moon phase.
(c) Looking directly at a solar eclipse can damage the eyes because the Sun’s harmful rays can cause permanent blindness. Special filters or glasses are required for safe viewing.
Question 4.
Sahil notices that on one particular night, the Moon looks completely round and bright.
(a) What is this phase of the Moon called?
(b) What causes the entire face of the Moon to be visible from Earth during this phase?
(c) How many days after a New Moon does a Full Moon usually occur? (NCERT Exemplar)
Answer:
(a) The phase is called the Full Moon.
(b) The Earth is between the Sun and the Moon, and the entire sunlit side of the Moon faces Earth.
(c) A Full Moon usually occurs about 14 to 15 days after a New Moon.
Question 5.
Meena saw the Moon clearly in the sky during the early morning hours, even though the Sun was already up. She was surprised and asked her teacher why the Moon was visible during the day. (NCERT Exemplar)
(a) Is it possible to see the Moon during the daytime?
(b) During which Moon phases is daytime visibility more likely?
(c) Why is the Moon visible even when the Sun is out?
Answer:
(a) Yes, the Moon is often visible during the day, depending on its position.
(b) The Moon is usually visible during First Quarter, Waning Gibbous, and sometimes Waxing Crescent phases.
(c) The Moon is visible because sunlight reflects off its surface, and it can appear in a different part of the sky than the Sun.
Keeping Time with the Skies Extra Questions for Practice
Question 1.
What do we call the Moon when it is more than half lit but not full?
Question 2.
Which phase comes just before the New Moon?
Question 3.
Does the Moon have air and water?
Question 4.
What is the Moon made up of?
Question 5.
Which direction does the Moon rise from?
Question 6.
What causes a lunar eclipse?
Question 7.
What is a Full Moon, and when does it occur?
Question 8.
What is meant by the term “natural satellite”?
Question 9.
Why is there no atmosphere on the Moon?
Question 10.
What are the differences between crescent and gibbous moons?
Question 11.
What happens during the First and Last Quarter phases?
Question 12.
Why does the Full Moon rise at sunset and set at sunrise?
Question 13.
Ravi took photographs of the Moon every night for a month. He noticed that the Moon started as a New Moon, grew into a Full Moon, and then returned to a New Moon.
(a) What is this complete process called?
(b) How long does this cycle take?
(c) Which phase comes just after the Full Moon?
Question 14.
During a beach vacation, Alok noticed the water level on the shore rising and falling twice a day. His father told him this happens because of the Moon.
(a) What is this phenomenon called?
(b) How does the Moon cause it?
(c) During which Moon phases are the tides the highest?
Question 15.
In an ancient village, people tracked the time by watching the Moon. Every time the Moon returned to the same phase, they marked the beginning of a new month.
(a) What type of calendar were they using?
(b) How many days are there in one complete Moon phase cycle?
(c) Why is the Moon useful for tracking time? (NCERT Exemplar)
Question 16.
Some children say that the Moon gives its own light because it shines at night.
(a) Does the Moon produce its own light?
(b) Then how is it visible to us?
(c) Which other object is responsible for lighting up the Moon? (NCERT Exemplar)
MCQs
Question 1.
Why don’t we have solar and lunar eclipses every month?
(a) The Moon doesn’t always orbit
(b) The sun doesn’t rise every day
(c) The Moon’s orbit is tilted
(d) Earth moves too fast
Question 2.
What is the Moon’s position during a solar eclipse?
(a) Behind the Earth
(b) Between Earth and Sun
(c) Beside the Earth
(d) Far away from Earth
Question 3.
Which direction does the Moon rise from?
(a) West
(b) North
(c) East
(d) South
Question 4.
How many major phases does the Moon have?
(a) 2
(b) 6
(c) 4
(d) 8
Question 5.
What is the term for the Moon when it appears to grow larger each night?
(a) Waning
(b) Waxing
(c) Gibbous
(d) Crescent
Fill in the blanks
Question 1.
A ______________ eclipse happens when the Earth comes between the Sun and the Moon.
Question 2.
The Moon rises in the ______________ and sets in the west.
Question 3.
The ______________ Moon phase occurs whenthe Moon is halfway lit and growing.
Question 4.
We do not see eclipses every month because the Moon’s orbit is ______________ tilted.
Question 5.
The extra bright part of the Moon during waxing or waning is called ______________ Moon.
True or False
Question 1.
New Moon comes just before Full Moon.
Question 2.
The Moon takes about 29.5 days to complete one revolution around the Earth.
Question 3.
The Moon’s orbit is perfectly circular.
Question 4.
Solar and lunar eclipses happen every month.
Question 5.
A waxing moon means the visible part is increasing.
Match the following
Question 1.
| Column A | Column B |
| (a) Solar Eclipse | (i) More than half, but not full |
| (b) Gibbous Moon | (ii) The Moon appears thinner each night |
| (c) Moon reflects sunlight | (iii) Moon between Earth and Sun |
| (d) First Quarter | (iv) Reason we can see the Moon |
| (e) Waning Moon | (v) Half of the Moon is visible (right) |