Earth as Bull's-Eye
May 16, 1998 | Volume 153 | Number 20Cover: The Manicouagan impact crater in Canada looks like a bloodshot eye in this image taken by the Landsat satellite. Carved out of Earth's crust 214 million years ago, this crater is one of five that may have formed simultaneously when fragments of an asteriod or comet struck Earth. (Image courtesy R.A. Grieve)
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News of the Week:Death Swept Earth at End of Permian
The greatest mass extinction in Earth’s history happened far quicker than scientists had once thought.
Studying California’s fastest drummers
A statistical analysis of more than 3,000 recordings of California woodpeckers dashes the long-debated idea that each species has unique drumming.
Study tracks violence among mentally ill
Discharged psychiatric patients who do not abuse alcohol or illicit drugs commit violent acts at the same rate as a random selection of their neighbors in urban communities.
Fetal deaths climb with air pollution
High concentrations of nitrogen dioxide and other combustion pollutants may contribute to late-term miscarriages.
Male hypertension may have genetic link
Two studies indicate that genetic variations in a region of the ACE gene may signal men who are at increased risk of high blood pressure.
Writing micropatterns in glowing silicon
A novel process for making porous silicon creates microscopic, light-emitting patterns on a crystalline silicon surface.
Estrogen flips testosterone gene switch
Estrogen may turn on some of the same genes as testosterone and other so-called male hormones.
Dust buster eyes fireworks in nearby galaxy
A near-infrared camera aboard the Hubble Space Telescope has recorded the first detailed portrait of the core of the closest galaxy to Earth that houses an active, supermassive black hole.
AnthropologyEarly hominid rises again
Scientists announced the discovery of additional fossils from Australopithecus anamensis, the earliest known human ancestor capable of walking upright.
Ball court bounces back in time
An excavation in Mexico revealed a ball court that was used about 3,400 years ago.
AstronomySome like it cold?
Astronomers have found the coldest star on record.
Backwards ring around Jupiter
Combining computer simulations with data gathered by a dust detector aboard the Galileo spacecraft, researchers have found evidence of a new, faint dust ring encircling Jupiter.
Ulysses marks a milestone
The Ulysses spacecraft has completed its first lap around the sun.
BiomedicineBreast milk component assails rotavirus
Breast milk contains lactadherin, a compound effective in combating the most common diarrhea-causing microbe.
Kidney stones and beverage choice
Coffee, tea, and wine may help a woman avoid kidney stones whereas grapefruit juice apparently increases the chances of getting a stone.
Geologists link a chain of craters
Five large asteroids or comets may have hit Earth 214 million years ago.
Tiny genetic loops aid cancer cells, offer target for therapy
Minichromosomes may help cancer cells proliferate.
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