Hadean


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Related to Hadean: Archean

Hadean

[′hā·dē·ən]
(geology)
The period (more than 3800 million years ago) extending for several hundred millions of years from the end of the accretion of the earth to the formation of the oldest recognized rocks.
References in periodicals archive ?
Life may have arisen during the Hadean, and last year Stephen Mojzsis (University of Colorado) reported evidence that it might have survived the Late Heavy Bombardment.
Enough material struck Earth during the Hadean that it could have extended the planet's entire surface by the height of Mount Everest.
Carnegie's Robert Hazen compiled a list of every plausible mineral species on the Hadean Earth and concludes that no more than 420 different minerals-about 8 percent of the nearly 5,000 species found on Earth today-would have been present at or near Earth's surface.
His ninth book of poetry, Hadean Eclogues, will be published by Story Line Press next year.
Finally, Deserts lifts one out of the Hadean blur to the dry land of a clear image.
Awakened to both the memory and the extent of the loss, young artists and poets see the new world with ancient eyes, revealed in an amazing, brilliant light; contemporary America transformed in the language of the Orphic lyre, the cities and suburbs come alive in all their strange, Hadean, Arcadian grotesqueness and beauty.
The findings are part of a paper called "Widespread Mixing and Burial of Earth's Hadean Crust by Asteroid Impacts" published in the journal Nature.
Judith Coggon at the University of Bonn, Germany, said that the first 600 million years of Earth are called the Hadean, as it was previously believed that at this period of the time, Earth was hellish and uninhabitable.
According to astrobiologists, these meteor strikes can be dated to the Hadean and Archean eons - the first of the four principal eons in the earliest history of Earth.
The scientists led by a University of South Florida astrobiologist found that during the Hadean and Archean eons - the first of the four principal eons of the Earth's earliest history - the heavy bombardment of meteorites provided reactive phosphorus that when released in water could be incorporated into prebiotic molecules.
No such rocks are known from the earlier Hadean eon (SN: 5/29/12, p.
But as the Earth cooled through this period, called the Hadean eon, it slowly became a more habitable place.