Environment

As you take in your next breath of air, you can thank a form of microscopic marine life known as plankton.

They are so small as to be invisible, but taken together, actually dwarf massive creatures like whales. Plankton make up 98 percent of the biomass of ocean life.

"This invisible forest generates half of the oxygen generated on the planet," Chris Bowler, a marine biologist, tells Guy Raz, host of weekends on All Things Considered.

And, as climate change alters the temperature and acidity of our waters, this mysterious ocean world may be in jeopardy.

NASA's Curiosity rover has found definitive proof that water once ran across the surface of Mars, the agency announced today. NASA scientists say new photos from the rover show rocks that were smoothed and rounded by water. The rocks are in a large canyon and nearby channels that were cut by flowing water, making up an alluvial fan.

"You had water transporting these gravels to the downslope of the fan," NASA researchers say. The gravel then formed into a conglomerate rock, which was in turn likely covered before being exposed again.

In Missouri, the bullfrog and green frog harvest season starts on the night of June 30th and last through the end of October.