If Earth was not tilted on it's axis would the Moon appear to follow a straight path in the sky?

Question

Rather than an arc or something? Wow, really learning some interesting things about my world. Thank you everyone!

Answer 1

Hi Kai!

The sun, moon, stars and planets would follow arcs, because the earth is round and rotates, so the celestial bodies seem to revolve around the earth.

The real effects, if the earth were not tilted 23 1/2 degrees on its axis, would be that the sun would not move north and south in the sky with the seasons.  

With the axis tilted, those who live on the equator see the sun rise due east, arc directly overhead, and set due west on March 20 and September 22nd.  In June, they see the sun rise in the northeast, arc across the northern sky and set in the northwest.  In December, the same in the southern sky.  

But if the earth were not tilted, every day would be the same: at the equator, sunrise due east, arc directly overhead, and set due west.  Other latitudes would see the rise and set in exactly the same place every day of the year and always reach an altitude equal to 90 degrees minus their latitude.  

At the north pole, the sun would stand permanently due south on the horizon and never, ever rise or set.  At the poles, there would be no arc.  Just a point.

The big difference if the axis were not tilted isn't that there'd be no arcs.  Rather, the arc would always be exactly the same every day of the year.

Answer 2

That would depend on the observers position on the earth,

whether the axis was tilted or not.

Also the 'tilt' of the moon's orbit would come into it.

Answer 3

No, it would always appear as an arc.  I presume you are talking about the Moon's monthly track around the sky as see from Earth.  It would not vary in apparent sky latitude (known as declination) nearly as much as it does now.

Answer 4

The Moon's orbit is tilted by 5 degrees with respect to the Earth's orbit around the Sun. If the Earth was not tilted on its axis, then the Sun would always follow the same path across the sky every day and the Moon's path would vary slightly, but never more than 5 degrees from the Sun's path. Both of these paths would appear as arcs, however, rather than straight.