I don't think anyone can guess this, so the answer is that it is a nebula, a cloud of gas and dust out of which new stars are born. See:
The Pillars of Creation and for what they are made of see Nebula.
The Pillars of Creation was one of the top ten images from Hubble.
I suspect this is the wrong forum to discuss space matters in. This is, after all the literature network forums.
So I suggest we keep to literature issues. Here is my new question, also space but in a literature context:
What scientific fact was mentioned in Jonathan Swift's Gulliver's Travels concerning the moons of mars?