(ËvÉr bÉl) adj. 1. of or consisting of words: verbal ability. 2. spoken rather than written; oral: verbal communication. 3. concerned with words only, rather than with the ideas, facts, or realities expressed: a purely verbal distinction. 4. corresponding word for word; verbatim: a verbal translation.
Because their hypothesis requires that Earth arose from water-containing materials already present in the inner solar system, it's called the wet-accretion hypothesis. Most of Earth's water has an indigenous origin, says Drake.
The new, hard evidence that there is water deep in the Earth comes from a tiny grain of rock â just four-hundredths of a millimetre in diameter â trapped inside the diamond. That grain was made of ringwoodite â a form of the green mineral peridot that has never before been found on Earth, except in meteorites from space.