The world's central banks are pumping cash into their economies, pushing down interest rates in hopes the ready cash and lower rates will boost borrowing and economic activity. Everyone agrees the action is dramatic and unprecedented, but there's disagreement over whether they will do more harm than good.
Economists know very well the trillions of dollars being added by the central banks to the global economy can be risky.
"These are risks about long-term rises in inflation, housing bubbles potentially building up," says Jacob Kirkegaard of the Peterson Institute.
NASA's newest Mars rover, Curiosity, has snapped photos of rocky outcroppings that jut out from the alien soil, and scientists say they look like the remnants of an ancient stream bed where water once flowed on the surface of the red planet.
The exposed rocks look like broken slabs of concrete sidewalk, about four inches thick, and are made of rounded bits of gravel in a sandy matrix. The rock has eroded a little bit, and some of the smooth pebbles — about the size of M&M candies — have fallen down into a little pile.