Astronomy Questions, Asking why?

Question

How many hours is it from sunrise to the next sunrise on Venus???

If you looked directly north on venus in the nightsky would you see the stars spinning CCW around polaris??? If not what would you see and why???

Imagine Earth stoped orbiting the sun, (stayed in the place that it was). how would this change our solor system model affect the apparent motion of the stars in the night sky on a day to day basis???

Imaging Earth stopped orbiting the sun, how would this change the apparent motion of the stars in the night sky on an hourly basis???(lookin at the stars continusly through the night)

Answer 1

The sunrise is not visible from the surface of Venus, because the atmosphere is too dense to enable the sun to be seen; however, if the sunrise WERE visible, it would occur every 224.7 earth days. That is, Venus rotates on its axis much more slowly than earth does.

Of course the stars are not visible from the surface of venus, either, for the same reason. However, if the stars were visible, the night sky would appear very differently from the way it appears from earth. The axis of Venus is tilted only three (3) degrees from vertical with respect to the plane of the ecliptic, as compared to the 23.5 degree tilt of the earth's axis.

For this reason, Polaris is not at the center of the north sky on venus as it is on earth. Venus's axis points in a different direction.

If the earth did not orbit the sun, it would soon fall into the sun as a result of the loss of centrifugal force to balance the sun's gravity. However, if through some magical process the earth could be made to stand still with respect to the sun, the appearance of the night sky would cease to change through the year. That is, the constellations would remain the same for a given point on earth every day of the year.

Your last question is related to the third. The sky would appear to change from hour to hour just as it does now, but the constellations that appear to move around the sky would be the same through the year instead of changing with the months and seasons as they do now.

Answer 2

A day on Venus is 243 Earth days, or 5,832 hours long.

The rotation of Venus is opposite that of Earth, so CCW is correct. Of course you cannot see the stars from the surface of Venus because of the clouds, and the north pole of Venus does not point at Polaris.

If Earth could stay still without falling into the Sun, then we would no longer see the other planets go through retrograde motions, because those retrograde loops are caused by the Earth's motion.

The daily motion of the stars would not change at all, but the Sun's motion would. It would no longer move from one Zodiac constellation to another each month. It would just stay in one constellation, permanently hiding the stars in that part of the sky with its glare.