To clarify, the translation of Tengri into the words Sky and Heaven is innacurate. Tengri actually means God but academics and religious exclusive types intentionally translate Tengri into an animistic impersonal concept such as sky or heaven. It’s also part of the cover up that attempts to disconnect world traditions from their Vedic roots. The ambivalent Blue sky and a very personal Blue embodied divinity have no real commonalities beyond the color.
Fortunately, when applying the linguistic historical traditional and cultural contexts it is beyond doubt that Koke Mongke Tengri means Blue Eternal God. See quote from my book below clarifying this point
Yet scholars continue to falsely identify Tengrism as animistic sky-awed nature worship rather than the intensely personal and devotional faith tradition it truly is. In fact Tanri, (Tengri) is often used by Turkik Muslims as a name for Allah just as the name Allah is still used in prayer by Maltese Christians even today.