Gauging Arctic’s summer sea ice melt

This past winter, Arctic sea ice extent sank to a record low for the 3rd straight year. Now, NASA is looking at the summer melt season's impact on the Arctic's oldest, thickest sea ice.

How to watch Shark Week

This is a week of dueling shark-athons on television. A biologist advises viewers to take what they see with a large grain of sea salt.

Synchronized symphony of fireflies

This video shows a timelapse journey through Smoky Mountains National Park during world's largest gathering of synchronized fireflies. Beautiful!

Global methane levels hitting new highs

Here's why, after a 2000-era plateau, global levels of the greenhouse gas are hitting new highs.

Fire ants build with no master plan

Researchers identified simple behavioral rules that allow these tiny creatures to collaboratively build elaborate structures - rafts and towers - with no one in charge.

Moon shadow versus sun reflection

This 5-second video shows a reflected image of the sun - a sun glint - as a bright spot crossing Earth from right to left. It also shows a dark spot - the moon's shadow - moving the opposite way.

Does your dog pronk?

Among wild animals, pronking may be a way of avoiding predators. But when you see an animal pronk, you can't but think it's leaping for joy.

Last survivors on Earth?

Scientists say they’re likely to be tardigrades - tiny, 8-legged marine creatures - which can survive until the sun dies, long after we humans have disappeared.

Massive iceberg breaks off Antarctica

An iceberg - about the size of the U.S. state of Delaware - split off from Antarctica’s Larsen C ice shelf sometime between July 10 and 12.

Possible new threat to Earth’s ozone layer

Recent increases in an unregulated ozone-depleting substance could delay recovery of Antarctic ozone levels by 5–30 years, say scientists.