The Perseid meteor shower has begun. While the best viewing typically occurs after midnight when your location faces forward into the meteor stream, this year’s full moon is bright enough to interfere with visibility. To get around this, it's best to start watching at dusk, before the moon rises. The Perseids are tiny bits of ice from comet Swift Tuttle, disintegrating as they enter Earth's atmosphere. About one in 20 meteors, however, is a background meteor from the asteroid belt, which can survive their fiery descent. These "sturdy" meteors can even crash through roofs at speeds of up to 250 miles per hour. Despite the rarity of such impacts, insurance usually covers the damage.

We explore the quirky world of units—from the 1999 Mars Orbiter disaster caused by a metric vs. imperial mix-up to the colorful ways we measure everything from chili pepper heat to cotton and paper. You'll learn why U.S. territorial waters were once based on the range of a cannon shot, how Fahrenheit’s scale reflects geometric symmetry, and why a "barrel" of oil isn’t the same as a barrel of beer. With oddball units like skeins, quires, and cords still in use, maybe it’s finally time we all bolted over to metric!

The Best of Our Knowledge explores topics on learning, education and research.It’s summertime and people are flocking to the beach.On today’s program we will talk about sharks! We will uncover why they are misunderstood and all the important information about the “perceived ultra-predator.”

We are joined by Dr. Joanne Favuzza of Capital District Colon & Rectal Surgery Associates, a practice of St. Peter’s Health Partners Medical Associates. Joe Donahue hosts.