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Time-Lapse Seasons Demonstrator

Sun transit — Hong Kong (22.3193°N)

Horizon (East ← → West)

The yellow curve is the Sun's full path that day. Press Play to watch the Sun transit and seasons advance.

Before you start

Watch how the Sun's daily arc across the sky changes from winter to summer — a time-lapse through the seasons.

Key idea

The Sun's path is highest and longest in summer (for your hemisphere) because Earth's tilt points you toward the Sun. In winter the path is lower and shorter.

What you see

  • Horizon dome with the Sun's daily path as a yellow curve
  • Moving Sun dot along today's path
  • Play button to animate transit and advancing seasons

Try this

  1. Set day to June 21 and watch the Sun climb high at noon
  2. Set day to December 21 and compare the lower arc
  3. Press Play to see a full day and season advance

Why it matters in Hong Kong

In Hong Kong, summer solstice Sun reaches about 88° altitude — nearly overhead.

Common mistakes

  • Thinking the Sun is always south at noon in the northern hemisphere (in tropics it can be north)

Glossary

Transit
When a celestial object crosses the meridian (due south/north).
Solstice
When the Sun reaches its most northern or southern declination.

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