Moon position in orbit (degrees)

0° (New) → 180° (Full)40°

Observer time of day

0 = midnight21.00 h

Animation

Play Step +5°

**Waxing Crescent**

Illuminated: **—**

**Try this:** Slide the Moon to 180° and set time to 0h (midnight). What phase do you see and where is the Sun?

### Quick Check

If the Moon rises at sunset, what phase is it?

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Day of year

~172 = June solstice172

Earth axial tilt (degrees)

Real Earth ≈ 23.5°23.5°

Observer latitude

-66.5° to +66.5°19.0°

Season: **—**

Day length: **—**

**Try this:** Set latitude to +19° (Hawaiʻi). Drag the day-of-year across the year. Notice how day length changes only a little near the tropics.

### Quick Check

What causes seasons (one phrase)?

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Your latitude (degrees)

Polaris altitude ≈ latitude (N hemisphere)19°

Polaris altitude: **—**

Visible? **—**

**Rule:** In the Northern Hemisphere, Polaris’s height above the horizon (in degrees) is about your latitude.

### Quick Check

If Polaris is 25° above the horizon, your latitude is:

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Local clock time when the Sun is highest (local noon)

This slider is GMT/UTC time at your local noon14.00 h

Time difference: **—**

Longitude: **—**

**Rule:** 1 hour of time difference = 15° of longitude. If your local noon happens when GMT is later, you are west of Greenwich.

### Quick Check

If local noon happens at 2 PM GMT, your longitude is:

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