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Flickr user Mark Gunn caught this humpback whale in Monterey Bay, off the coast of California, on March 27, 2016. He said the whale's flukes (tail) spanned 15 feet (4.5 meters).

Humpback whales, heroes of the sea?

Humpback whales appear to rescue not just their own species, but also other whale species, seals and sea lions from attacks by killer whales.

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Upside down rainbow-like arcs

Circumzenithal arcs have been described as an “upside down rainbow” or “a grin in the sky.” They’re wonderful! See photos here.

Camp Century doubled as a top-secret site for testing the feasibility of deploying nuclear missiles from the Arctic during the Cold War.

Ice melt may release Cold War-era toxins

Formerly secret Camp Century in Greenland was abandoned beneath ice and snow. But the ice is melting, and biological, chemical and nuclear waste may be released as early as 2090.

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First map of thawing under Greenland ice

Greenland’s ice sheet insulates its own bottom layer, which is warmed from below by Earth’s heat. Which bottom layers are now thawed, and which are still frozen?

Image via Michelle's blue planet

Lifeform of the week: Sea stars

You call them starfish? They’re brilliant by any name.

Image via Sarah2 / shutterstock / theconversation

Parakeet takeover ahead?

“Parakeets are Britain’s fastest growing bird population and are on a trajectory to global domination.”

July 30, 2016. Image via NASA

California wildfire from space

For 11 days, the Soberanes fire has been burning near the California coast between Monterey and Big Sur. Here are some satellite views.

Image via SKYGLOW

Gorgeous Dry Tortugas night skies

The National Park Service normally doesn’t allow night photography at the Dry Tortugas, but made an exception for this project.

Image via National Park Service

How much warning for supervolcanoes?

Yellowstone supervolcano could deposit ash across the U.S. Northwest, clogging rivers and streams and affecting agriculture. How much advance warning might we have?

Image via Vanderbilt University

Being called a bird brain is no insult

A new study has found that bird brains have significantly more neurons than do mammal – even primate – brains of the same mass.