Can you see the stars during daytime if you go deep enough down a hole so it is dark and look up?

Question

There is a deep vertical cave in New Zealand called Howard's Hole. Rumours say that it is SO deep that when you go down during daylight it is SO dark at the bottom that when you look up you can see the stars.

Is this possible? I thought that it would be impossible to see the stars during daytime no matter how deep the hole. Will the bright daylight still not obscure the stars no matter how deep you are? You can not use an optical telescope during daylight, no matter how powerful it is to see the stars so why would a deep hole be any better.

Answer 1

The brightness of the sky doesn't change, so no, you can't see stars in the daytime by going down a hole.

Answer 2

It is possible to see planets during the day if you know where to look. They can be most easily seen when they are very close to the Moon if it is up during the day. During an occultation of Venus by the Moon a couple of years ago Venus could clearly be seen in broad daylight. Going down a well or to the bottom of a tall chimney makes no difference. When looking at the sky, the eyes focus on the middle distance and any stars or planets that could be seen are out of focus. The moon gives a focal reference at a great distance so nearby planets are brought into focus and can be seen.

It is possible that the myth started because someone deep in a cave or at the base of a chimney saw a planet such as Venus which just happened to be in the right position, and attributed the sight to the darkness of the cave when, in fact, the planet could have been seen just as clearly from a position on the surface.

Answer 3

No.
The sky's brightness doesn't change, no matter how deep the hole.
The only star you'll be able to see during the day (barring a total eclipse) is the Sun.

Answer 4

its the suns light in the day time that makes it difficult to see the stars, no matter how deep down a cave you go.