How do I make a hollow sphere?

Question

So my journey here is only days old, but am already struggling. I am trying to duplicate this:

I've watched countless videos and repeated the best I can learn so far. So on my first sphere I've created this:

At a different angle:

As you can see, I've created the hole, but the cylinder I used is now sticking out the other side, which I'm not sure how to remove, any thoughts?

Is this really the best way to create those hollow spheres, similar to the planets picture I pasted?

I downloaded blender yesterday (V. 2.83.1). Many of the YouTube videos I've watched are difficult to follow and often only relate to older versions, so finding one that will be 2.8 specific has proved to be difficult (might be that I'm so new to Blender so finding it difficult)

Answer 1

It looks as if you already used a cube with subdivision surface modifier to get your sphere. While not a bad idea, i'd recommend to use at least subdivision level 4 for a cleaner sphere, otherwise it's not really as spherical as you'd want.
Thanks to Trey Harper for pointing out the cast modifier, i barely use, which in this case though really improves the result.

That said, going from your (cube)sphere:

1. Apply the subdivision surface modifier on your cube(remember lvl 4, for a more spherical sphere) and a cast modifier with the factor of 1:
   
   Marked red, important before going on is to apply these modifiers in order!
2. Go in front view Num 1, activate edit mode Tab and x-ray mode Alt+Z, select half of the sphere like this:
   
   when selecting, leave the center deselected to keep a half
3. With the selection, press X and choose Vertices
4. In the Object Data Properties we need to activate the Normals>Auto Smooth:
   
   Auto Smooth is needed for the next step to look clean at the cut
5. Go back in object mode Tab and add a solidify modifier.
   
   
6. Adjust the modifier to your needs and you have one shell done.

You can now copy Shift+D the created shell and adjust it's size to gain the other layers of the planet.

Here a little visual demonstration:

The thickness of each layer can easily be adjusted in the modifier

As the core looks like a full sphere, you should have all needed means to your cause now.

Happy Blending

Answer 2

Here's my take on this problem using modifiers as much as possible.

Start the same, with a roundcube found in the Extra Objects add-on, and cut it in half.

It is helpful before going any further to snap the cursor to the roundcube with Shift+S>cursor to selected and then add an empty which is the object of interest for the array modifier. Keeping the empty and quadsphere at the same origin will simplify the process greatly.

Next, we need some modifiers.

Solidify for thickness, Edge Split to sharpen things up some, Subdivision Surface to smooth things out, and an Array.

This is the stack in the image below:

(note that the object offset is ticked in the array modifier)

Next you can simply scale down the empty and translate in the x direction.

Here is an example .blend to inspect:

Answer 3

the best way to create a hollow shpere is to use a solidify modifyer, which will add a layer to the mesh, making it hollow on the inside. hope this helps!