NASA’s Apollo missions to the Moon brought back about 382 kilograms (842 pounds) of samples, including rocks, rock cores, rock, pebbles, sand, and dust. Scientists have studied those samples intently over the decades and have learned a lot. But they haven’t studied all of the samples.
In an impressive act of foresight, NASA left some of the samples unopened and in pristine condition. Why? Because they knew the technology used to study the samples would only improve over the decades.
Where did Earth’s water come from? That’s one of the most compelling questions in the ongoing effort to understand life’s emergence. Earth’s inner solar system location was too hot for water to condense onto the primordial Earth. The prevailing view is that asteroids and comets brought water to Earth from regions of the Solar System beyond the frost line.
But a new study published in the journal Nature Astronomy proposes a further explanation for Earth’s water. As the prevailing view says, some of it could’ve come from asteroids and comets.
But most of the hydrogen was already here, waiting for Earth to form.