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Largest-ever Gulf of Mexico dead zone

For 32 years, scientists have tracked the oxygen-depleted waters that appear each summer in the Gulf of Mexico. This year’s dead zone is the biggest yet.

It’s smoky in the Pacific Northwest

The smoke is from wildfires, an increasingly common occurrence at this time of year. It can’t be welcome news to those who’ve planned trips to that area for the August 21 total solar eclipse.

Intense Antarctic melt season causes decade-long effects

Multi-decade study reveals changes in Antarctica’s Dry Valleys and suggests “significant transformations of Antarctic ecosystems are underway now and will continue to be affected by future climate events.”

Earth’s eclipses are special

Solar eclipses aren’t exclusive to Earth, but eclipses viewed from our planet have few rivals in the solar system. A word about Earth’s solar eclipses, and what eclipses would be like on other planets, here.

To restore soils, feed the microbes

Healthy soil teems with bacteria, fungi, viruses and other microorganisms that help store carbon and fend off plant diseases.

Iridescent cloud? Or circumhorizon arc?

It’s easy to confuse these 2 elusive, colorful, beautiful daytime sky phenomena. How can you tell the difference?

How do jellyfish swim?

Jellyfish float on ocean currents, but they also swim in a couple of different ways. This post has 2 videos showing 2 different jellyfish propulsion mechanisms.

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!

Why fireflies light up

A firefly’s familiar glow is caused by chemical reaction. Explanation here, plus many wonderful firefly photos.

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.

How to see a green flash

It’s said that once you’ve seen a green flash, you’ll never go wrong in matters of the heart. Here’s all you need to know … plus great pics!

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.

California’s Alamo Fire, from space

Large plume of smoke from the Alamo Fire in southern California, blowing over the eastern Pacific on July 9. Areas burning actively at that time appear in red.