There are about 6,000 stars visible to the naked eye throughout the sky, but because we can only see half of the celestial sphere, we can see about 3,000 stars at the same time. What we are talking about here is an ideal situation. If there is light pollution or the air is not very transparent, this number will drop significantly. For example, in urban Beijing, even under the best weather, you can’t see 100 of them.