Globe & Time Zones

This simulation shows a spinning Earth lit by the Sun, with the boundary between day and night marked and the 24 time zone meridians drawn. Students set the UTC hour and the day of the year, or let the globe turn automatically, and read the UTC time, the Sun declination and the point where the Sun is directly overhead. They see that noon moves westward at fifteen degrees an hour, and that the day and night line tilts through the year. It supports geography and Earth science lessons on time, seasons and axial tilt.

• Turn Auto spin on and watch the day and night line sweep around the globe.
• Drag UTC hour and watch the Sun overhead at readout move westward.
• Set Day of year near 172 and then near 355 and compare the Sun declination.
• Find where it is noon by looking at the point under the Sun.
• Count the meridians to see why neighboring time zones differ by about one hour.

1. 1Explain why the Earth has 24 time zones about 15 degrees wide.
2. 2Describe how Earth rotation causes day and night.
3. 3Relate the tilt of the Earth to the changing Sun declination through the year.
4. 4Work out the local time in one place from the time in another.

Questions teachers ask