"There are lots of stars in the sky tonight" (or with "many stars") is the idiomatic translation. All these sentences with "έχει" - "has" is fine for the literal translation, but you just don't say it like that in English.
Yes, there are always a lot of stars in the sky, but the expression "there are a lot of stars in the sky." is very common in English and I image actually means "there are a lot of stars visible tonight." But we seldom add the visible.