What is "rare earth"

n. (context chemistry English) naturally occurring oxides of the lanthanide metals; they are widely distributed in relatively small concentrations and are used in glassmaking, ceramic glazes etc

n. any element of the lanthanide series (atomic numbers 57 through 71) [syn: rare-earth element, lanthanoid, lanthanide, lanthanon]

Rare Earth is an American rock band affiliated with Motown's Rare Earth record label (named after the band), which prospered from 1970–1972. Although not the first white band signed to Motown, Rare Earth was the first big hit-making act signed by Motown that consisted only of white members. (None of the previously signed all-white acts The Rustix, The Dalton Boys, or The Underdogs had any hits.)

Rare earth may refer to:

• Rare earth elements, a group of elements on the periodic table
• Rare earth mineral, a mineral substantively composed of these elements
• Rare-earth magnet, a type of magnet that employs rare earth elements to increase effectiveness
• Rare Earth hypothesis, the theory that complex life in the universe is exceptionally rare
• Rare Earth (book), a book by Peter Ward, a geologist and paleontologist, and Donald E. Brownlee
• Rare Earth (band), an American musical group
• Rare Earth Records, a subsidiary of Motown Records which produced rock music

Rare Earth: Why Complex Life Is Uncommon in the Universe is a 2000 popular science book about xenobiology by Peter Ward, a geologist and paleontologist, and Donald E. Brownlee, an astronomer and astrobiologist, both faculty members at the University of Washington. The book is the origin of the term ' Rare Earth Hypothesis' which, like the book, asserts the concept that complex life is rare in the universe. The book was eventually succeeded by a follow-up book called The Life and Death of Planet Earth, also by Ward and Brownlee, which talks about the Earth's long term future and eventual demise under a warming and expanding Sun, showing readers the concept that planets like Earth have finite lifespans, and complex life is not just rare in space, but also rare in time, and is more likely to die out within a short time on geological timescales, while microbes dominate most of the planet's history.