Observing the sky Flashcards
What is a side real day?
The time taken for a star to return to the same position in the sky.
How long is a side real day?
Approximately 23 hours and 56 minutes
What is a solar day?
The time taken for the sun to return to the same position in the sky
How long is a solar day?
24 hours
Why are solar days slightly longer that side real days?
Because the earth orbits the sun as it spins on it’s axis therefore the earth has to spin slightly more that 360 degrees for the sun to be in the same place in the sky.
Roughly how long does it take for the moon to appear in the same position in the sky?
25 hours
Why does the moon take longer to appear in the same position in the sky?
Because the moon orbits the earth in the same direction that earth is rotating. After the earth has spun 360 degrees the moon has also moved along a little so the earth has to spin more for it to be in the same place.
How long does it take for the earth to rotate the sun?
1 year
