> Yes, water is common—in fact, it is the third most common molecule in the universe.

What are the first 2 most common molecules? H2 and O2?

In another thread on HN this morning, we learned that Hydrogen, Helium, & Oxygen are the 3 most common elements in the universe. To tangent off a different commenter's remark, the 1st and 3rd most common elements in the universe create the 3rd most common molecule.