What is a Sidereal Day?
The time it takes the earth to orbit the sun?
The time from noon one day, to noon the next.
The time it takes for the earth to rotate 360 degrees
the time it takes for a salad to poop
How long does it take the moon to orbit the earth?
A month
28 days
7 days
365 days
Select the correct definition of "retrograde motion" as well as the correct explanation for why it happens?
Retrograde motion: The apparent backwards movement of planets from west to east against a fixed background of stars.
Retrograde motion: The complex movement of planets as they move through a solar system.
The solar system is constantly changing and moving. Some planets appear to move backwards because they are changing the direction of their orbit and moving in a different way from what they were before.
The earths smaller orbit causes it to overtake the outer planets at certain times. This causes the planets to appear to slow down and go into reverse against the star background.
What are the angles of "declination" and "right ascension" used for?
measuring how far away stars are from earth
measuring how fast the earth is rotating
showing us how far apart certain stars are
describing the position of stars in relation a fixed point on earths equator
Where is an example of a place a star wit negative declination would be visible?
New Zealand
the UK
Libya
China
