My time has come!
The above stereographic image is for cross-eyed viewing (most stereograms are wall-eyed, so you may need to put your finger in front of your screen until this one comes into focus)
This is an image of Honolulu, Hawaii, published by NASA. Note Diamond Head (the volcanic crater) in the south.
Here are some other stereopairs published by JPL:
Wheeler Ridge, California
Mount Saint Helens
Salt Lake Valley, Utah
Wellington, New Zealand
You're doing "wall eyed" viewing. These are for "cross-eyed" viewing. "Wall-eyed" means your eyes are focusing at a point behind the image. You need to cross your eyes for these. Try putting your finger in between your screen and your eyes, varying the distance until the dots merge. Then, remove your finger, focusing on the image itself. That should allow for cross-eyed viewing.
So weird. I can do this with my finger in the way but for some reason cannot hold my eyes in that position - as soon as I take the finger away my eyes unfocus. Maybe because it's do uncomfortable to hold that eye pose?
Yeah, try the wall-eyed version I posted as a top-level comment
yeah that's much easier