The duration of a solar eclipse is set by the relative speeds of the Moon’s shadow, sweeping west to east at 3,200 km/h, and of the observer who is traveling west to east with the Earth’s spin. The Earth moves fastest at the equator: 1,600 km/h. The observer there is more nearly keeping up with the shadow than any other observer and sees the longest eclipse.
Similarly, a total eclipse of the Moon can last as long as it takes the Moon to pass through the widest part of the Earth’s shadow. Unlike a solar eclipse, which is visible only along a confined track across the Earth’s surface, a lunar eclipse can be seen by anyone who can see the Moon.
- What is the length of day and night on the moon?
- Do other planets experience total solar eclipse like the one we witnessed on July 22, 2009?
- What is the exact number of stars? What method is used by the astronomers to count them?