The thundering roar at the base of Niagara Falls is awesome indeed. On an average summer day, about 40 million gallons of water spill over the half-mile–wide Canadian portion of the cataract each minute. After falling over a cliff taller than a 16-story building, water pummels the rocks below, incessantly eroding the base of the cliff and triggering rockfalls. Before the 20th century, when engineers weakened the Niagara River by diverting some of its flow to produce hydroelectric power, the falls marched upstream an average of more than a meter per year. Niagara Falls is one of the last ... (p. 18)

Satellite data reveals that increased irrigation pressure is rapidly depleting groundwater in northern India. (p. 5)

Airborne sensors can identify mineral outcrops and soil that may contain natural asbestos. (p. 14)

Scientists identify how a hydrocarbon commonly emitted by plants is converted to light-scattering aerosols. (p. 15)

Rapid anatomical changes in rodents linked to increases in human population density, precipitation.

Macromolecule that was accidentally discovered seems to trap carbon dioxide from the air.

Simultaneous snapshots reveal that northern and southern auroras aren’t always alike. (p. 14)

Structures found in Australian rocks may be the filled-in remains of the world’s oldest dinosaur burrows.

NASA previews digitally restored footage from Apollo 11.

New analyses of Arctic seafloor sediments suggest floating ice debuted in the ocean at least 47.5 million years ago. (p. 14)

Experiments show how microscopic fungi attack minerals to begin the erosion process. (p. 15)

A new model predicts that rises in sea level, combined with subsiding lands, will claim a tenth of the state by century’s end. (p. 15)

Simulations also suggest that the dearth of ozone over Antarctica leads to ocean acidification. Simulations also suggest that the dearth of ozone over Antarctica leads to ocean acidification