Why sun rises in the east

Try this! Shine a flashlight on the side of a ball and rotate the ball counterclockwise. You can figure out which way to turn it by looking down on the ball from above and thinking of a clock face. Watch what happens to the light and dark areas as the ball turns. This is what happens on the earth as it rotates toward the east counterclockwise. Back to Beginning. All rights reserved.

Is there anything simpler than knowing that the Sun rises in the east and sets in the west? After all, it happens every day of our life, right? Sunrises and sunsets happen because Earth spins, counter-clockwise if we look down at the North Pole. We can use the same reasoning to explain a similar phenomenon for the Moon.

So moonrise will also shift north or south of due east as the Moon completes its orbit. In this case, though, the changes occur over the period of roughly a month instead of a year. Earth must complete a full orbit for the Sun to go through its extremes, rising the furthest north of east during summer solstice and the furthest south of east during winter solstice.

The same holds for the Moon, which must also complete a full orbit around Earth to go through the extremes of its rising and setting locations. As already noted, the Earth rotates on its axis as it circles the Sun. If viewed from above the celestial north, the Earth would appear to be rotating counter-clockwise. This is also true of the majority of the planets in the Solar System.

Venus is one exception, which rotates backwards compared to its orbit around the Sun a phenomena known as retrograde motion. Uranus is another, which not only rotates westward, but is inclined so much that it appears to be sitting on its side relative to the Sun. Pluto also has a retrograde motion, so for those standing on its surface, the Sun would rise in the west and set in the east. In all cases, a large impact is believed to be the cause. In essence, Pluto and Venus were sent spinning in the other direction by a large impact, while another struck Uranus and knocked it over on its side!

With a rotational velocity of 1, This means, in essence, that a sidereal day is less than 24 hours. But combined with its orbital period see below , a solar day — that is, the time it takes for the Sun to return to the same place in the sky — works out to 24 hours exactly.