This worksheet features a diagram of Earth's tilt and orbit, asking students to identify seasons and sunlight angles based on labeled points.

Let’s go step by step to solve each question on the worksheet.

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Question 1: During which month(s) does Earth lie in the plane of the ecliptic?

The diagram shows Earth at different positions around the Sun, labeled with months and solstices/equinoxes. The “plane of the ecliptic” is the flat plane that contains Earth’s orbit around the Sun. Earth is always in this plane — it doesn’t leave it! But the question likely means: when is Earth positioned so that the Sun appears directly over the equator (i.e., during equinoxes), because that’s when day and night are equal everywhere.

Looking at the diagram:
- March 21 = Vernal Equinox → Sun over equator
- September 23 = Autumnal Equinox → Sun over equator

So Earth lies in the plane of the ecliptic *in terms of alignment for equinoxes* during March and September.

But wait — actually, Earth is ALWAYS in the plane of the ecliptic. That’s its orbital path. So maybe the question is tricking us? Let’s read again: “During which month(s) does Earth lie in the plane of the ecliptic?”

Actually, looking at standard astronomy: Earth’s orbit defines the ecliptic plane. So Earth is always in it. But perhaps the diagram is showing something else? Wait — no, the diagram labels positions like “June 21”, “Dec 21”, etc., and those are points along the orbit — all in the same plane.

Hmm… Maybe the question is misworded? Or perhaps it’s asking when the Sun is in the plane of the celestial equator? No — let’s look at the answer choices given in the multiple choice below Question 1:

> a) January
> b) February
> c) March
> d) April
> e) May
> f) June
> g) July
> h) August
> i) September
> j) October
> k) November
> l) December

And the instruction says: “Circle ALL that apply.”

From the diagram, we see two key dates where the terminator (line between day/night) goes straight through poles — meaning Sun is directly over equator: March 21 and Sept 23.

In many textbooks, they say Earth crosses the celestial equator (which corresponds to being aligned such that Sun is over Earth’s equator) during equinoxes — March and September.

Even though technically Earth is always in the ecliptic plane, I think the intent here is to ask: during which months do we have equinoxes? Because that’s when the Sun is directly above the equator, and Earth’s axis is perpendicular to the Sun-Earth line.

So based on common curriculum interpretation: March and September

✔ Answer: c) March and i) September

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Question 2: Which location would have the greatest number of daylight hours on June 21?

June 21 is the summer solstice in the Northern Hemisphere. On this date, the North Pole is tilted toward the Sun, so locations farther north get more daylight — up to 24 hours at the Arctic Circle and beyond.

Looking at the diagram, point A is near the North Pole (above Arctic Circle). Point B is on the Tropic of Cancer. Point C is on the Equator. Point D is on the Tropic of Capricorn. Point E is near South Pole.

On June 21:
- A (near North Pole): 24 hours of daylight (midnight sun)
- B (Tropic of Cancer): longest day but not 24 hrs — about 13–14 hrs depending on latitude
- C (Equator): ~12 hours
- D & E: less than 12 hours

So A has the most daylight.

✔ Answer: a) A

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Question 3: Locations A, B, C, and D all have the same...

Let’s check what’s the same.

All four points are on Earth’s surface. They’re at different latitudes.

What could be the same?

- Altitude of Polaris? No — altitude of Polaris equals your latitude. A is high latitude, D is low or southern — so different.
- Time of sunrise? No — varies by longitude and season.
- Angular distance from the zenith of the Sun at noon? No — depends on declination and latitude.
- Distance from the center of Earth? YES! All points on Earth’s surface are approximately the same distance from Earth’s center — assuming Earth is a sphere (which we do for these diagrams).

Earth isn’t a perfect sphere, but for educational purposes, we treat it as one. So radius is constant.

✔ Answer: d) distance from the center of the Earth

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Question 4: At which position is the observer located if the altitude of Polaris is 90°?

Altitude of Polaris = observer’s latitude.

If altitude is 90°, that means you’re standing right under Polaris — which is directly above the North Pole.

So you must be at the North Pole.

Look at the small globe diagrams:

(1) Observer at equator → Polaris at horizon (altitude 0°)

(2) Observer at mid-northern latitude → Polaris halfway up

(3) Observer at North Pole → Polaris directly overhead (altitude 90°)

(4) Observer in southern hemisphere → can’t see Polaris well, or it’s below horizon

So only position (3) matches.

✔ Answer: c) (3)

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Now let’s compile final answers clearly.

Final Answer:
1. c, i
2. a
3. d
4. c