H2O

Here, at depths of 5km, where no sunlight can penetrate, the oxygen appears to be produced by naturally occurring metallic “nodules” which split seawater - H2O - into hydrogen and oxygen.

However, in interaction with proteins, D2O is less potent than H2O.

Jupiter's rampant radiation breaks H2O's molecular bonds, leaving behind oxygen and hydrogen.

Federal prosecutors put the total amount of all contracts paid to H2O Process Systems by Maui County at around $19.3 million since 2012.

That means we need better prediction and detection—and we'd need astronauts to stay close to their H2O shield.