Nell Greenfieldboyce Nell Greenfieldboyce is a NPR science correspondent.
Nell Greenfieldboyce 2010
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Nell Greenfieldboyce

An artist's rendering of the Chicxulub impact crater on Mexico's Yucatan Peninsula from an asteroid that slammed into the planet some 65 million years ago. SPL/Science Source hide caption

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SPL/Science Source

Asteroid Impact That Wiped Out The Dinosaurs Also Caused Abrupt Global Warming

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Since early 2013, 110 chimpanzees have been retired to Chimp Haven sanctuary in Keithville, La., from the New Iberia Research Center in Lafayette, La. That's the largest group of government-owned chimps ever sent to sanctuary. Sabrina, seen here, arrived at Chimp Haven in 2013. Brandon Wade/AP Images for The Humane Society hide caption

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Brandon Wade/AP Images for The Humane Society

The prehensile tailed skink from the highlands of New Papua New Guinea has green blood due to high concentrations of the green bile pigment biliverdin. The green bile pigment in the blood overwhelms the intense crimson color of red blood cells resulting in a striking lime-green coloration of the muscles, bones, and mucosal tissues. Courtesy of Christopher C. Austin/LSU hide caption

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Courtesy of Christopher C. Austin/LSU

Why Do Some Lizards Have Green Blood?

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The planet, known as Kepler-452b, was believed to be about 60 percent larger than our planet and within the habitable zone of its star. NASA Ames/JPL-Caltech/T. Pyle hide caption

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NASA Ames/JPL-Caltech/T. Pyle

Earth's 'Bigger, Older Cousin' Maybe Doesn't Even Exist

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The European spacecraft known as Gaia has unveiled this new view of the Milky Way. ESA/Gaia/DPAC hide caption

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ESA/Gaia/DPAC

You Are Here: Scientists Unveil Precise Map Of More Than A Billion Stars

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An artist's representation of NASA's Transiting Exoplanet Survey Satellite, or TESS, observing an M dwarf star with orbiting planets. NASA Goddard Space Flight Center hide caption

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NASA Goddard Space Flight Center

Get Ready For the Next Big Thing In NASA's Search For Earth's Twin

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An artist's rendering shows the Milky Way where a supermassive black hole lies at the center. A dozen smaller black holes have now been detected, and a new study suggests the monster is surrounded by about 10,000. Spitzer Space Telescope/NASA/JPL-Caltech/R. Hurt (SSC/Caltech) hide caption

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Spitzer Space Telescope/NASA/JPL-Caltech/R. Hurt (SSC/Caltech)

Center Of The Milky Way Has Thousands Of Black Holes, Study Shows

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Dr. Garen Wintemute at the University of California, Davis, Medical Center, says of the new authority given to the Centers for Disease Control and Prevention: "There's no funding. There's no agreement to provide funding. There isn't even encouragement." Rich Pedroncelli/AP hide caption

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Rich Pedroncelli/AP

Government Spending Bill Could Change How Health Agencies Study Guns

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A model of the Tiangong-1 space station at a Chinese airshow in 2010. The real Tiangong-1 will reenter the atmosphere around the end of March. Kin Cheung/AP hide caption

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Kin Cheung/AP

A Chinese Space Lab Will Soon Fall From The Sky. Where It Lands, No One Knows

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Colored transmission electron micrograph of a section through an Escherichia coli bacterium. This rod-shaped bacterium moves via its hair-like flagellae (yellow). Kwangshin Kim/Science Source hide caption

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Kwangshin Kim/Science Source

Artist's rendering of how the first stars in the universe may have looked. N.R.Fuller/National Science Foundation/Nature hide caption

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N.R.Fuller/National Science Foundation/Nature

Did Dark Matter Make The Early Universe Chill Out?

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A Przewalski mare with her foal at the Highland Wildlife Park in Kingussie, Scotland, in 2013. It turns out that Przewalski's horses are actually feral descendants of the first horses that humans are known to have domesticated, around 5,500 years ago. Jeff J. Mitchell/Getty Images hide caption

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Jeff J. Mitchell/Getty Images

Why The Last 'Wild' Horses Really Aren't

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Smallpox virus, colorized and magnified in this micrograph 42,000 times, is the real concern for biologists working on a cousin virus — horsepox. They're hoping to develop a better vaccine against smallpox, should that human scourge ever be used as a bioweapon. Chris Bjornberg/Science Source hide caption

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Chris Bjornberg/Science Source

Did Pox Virus Research Put Potential Profits Ahead of Public Safety?

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