moon tower

[Salamander]

The latest strip of "Escape from Terra" has an interesting feature.

It got me thinking though, is the moon's axis tilt close enough to 90° towards ecliptic to allow the tip of a 1 mile high tower (1602m) to be in perpetual sunlight?

I was unable to find an data the moon's axis tilt at all.

On earth a similar tower would have to be 573km in height to counter the 23.45° axis tilt.

 

[Urwumpe]

The axis of the moon is pretty much perfectly aligned with the normal of the orbit plane, and the lunar orbit plane is just 5.5° to the ecliptic

because of the smaller radius of the moon, 1600 meter sounds pretty realistic.

 

[RisingFury]

Not to mention those pesky craters...

 

[Salamander]

well, with 5.145° tilt and 1,735.97 km radius i still get 7.022 km

 

[Urwumpe]

I get 2001 meters for the tower:

t = r * (1-cos(2.75))/cos(2.75)

(Remember that the "hill" of the moon has its peak at half the angle between axis and ecliptic)

 

[Salamander]

i used this formula:

h=(sqr(1+tan(5.145)^2)-1)* 1,735.97 km

the argument being that the tower would have to be the distance between surface of the moon and a tangent 5.145 degrees from the tower.

 

[Urwumpe]

Looks pretty sophisticated... and yes, you are wrong, since the tangent is only half the distance away, if you want to calculate the maximal distance from the pole.

 

[Salamander]

i figure it this way. what's wrong with it?

 

[Urwumpe]

Just measure the angle between line of sight to the sun and the angle between the pole. Then you will see.

 

[Salamander]

the sun is on the horizon in that example, so it would be zero