In protoplanetary disks, water is virtually omnipresent. Recent studies of the water content of early planetary systems like ours show that water is an abundant and ubiquitous molecule, originally synthesized on the surface of tiny grains of interstellar dust by hydrogenation of frozen oxygen, reports the journal Elements. In the molecular cloud from which a new planetary system will emerge, oxygen attaches and freezes to the dust grains it encounters. Once a hydrogen molecule intersects with this frozen oxygen, water ice is formed.