Enjoying EarthSky? Subscribe.

254,372 subscribers and counting ...

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.

Supernumerary rainbow over NYC

Look inside the bright primary bow for colorful fringes, whose number and spacing can change from minute to minute. Alexander Krivenyshev caught this one over New York City on Saturday, July 8.

Sunspot, and chance of weekend storms

Experts say there’s a 60% chance this weekend of geomagnetic storms, possibly causing auroras. Plus, over the past couple of days, a lone sunspot has grown rapidly!

Breathtaking night-shining clouds

Wonderful video showing noctilucent – or night-shining – clouds recorded on July 1 and 4. These clouds shine in the darkness, typically on summer nights.

How to see anticrepuscular rays

To catch a glimpse of elusive anticrepuscular rays: Next time you see crepuscular rays – sunrays – at sunrise or sunset, turn around.

If greenhouse gas emissions ended now…

Would climate change stop? The simple answer is no. A climate scientist explains.

Earthquake rocks Montana early Thursday

The 5.8-magnitude earthquake in western Montana took place just after midnight, local time. It woke people up near the epicenter and was felt throughout the region. Expect aftershocks.

Tunguska explosion

We celebrate Asteroid Day on June 30 because it’s the anniversary of a 1908 explosion over Siberia that killed reindeer and flattened trees.

Rainbow reflected at sunset

To capture an image like this one, where the sky rainbow and reflected rainbow in the water make a perfect circle, your timing has to be perfect.

An upside down rainbow?

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

US Southwest wildfires still burning

Across the US Southwest – amid a record-breaking heat wave – fires that started in early June continue to burn.

How to see a full circle rainbow

It’s possible to see the whole circle of a rainbow – but sky conditions have to be just right. Plus you have to be up high!