Enjoying EarthSky? Subscribe.

254,509 subscribers and counting ...

How close will asteroid 2012 TC4 come?

Asteroid 2012 TC4 might give Earth a close shave in October, 2017. Or the asteroid could pass more distantly. Astronomers are keen to observe it now, to learn more about its orbit.

Video: Moon hoax not

SG Collins explains why the Apollo moon landings on the moon in the late 1960s and early ’70s couldn’t have been faked.

Today in science: 1st footsteps on moon

Today is the 48th anniversary of humanity’s historic first steps on the moon. The story in pictures, here.

A shadow-band project for August 21

Shadow bands are elusive ripples of alternate light and dark, flitting over the ground or the sides of buildings during a total solar eclipse. How to take part in an International Shadow Band Campaign during the August 21 eclipse.

Maryam Mirzakhani, mathematician, dies at 40

She was an outstanding mathematician and first woman to receive the prestigious Fields Medal. Maryam Mirzakhani died on July 14 after a several-year battle with breast cancer.

Have you seen the Mayak satellite?

On July 14, an amateur group in Russia launched a small satellite called Mayak. They said it would become the “brightest shooting star” in the sky. Why’d they do it? Here’s how to look for it.

Soar over Pluto and Charon

To celebrate the 2-year anniversary of New Horizon’s flyover of the Pluto system, NASA released these 2 cool videos. Sail over the surface of Pluto and its large moon Charon.

Strange radio signals from nearby star

A 10-minute observation in May of nearby star Ross 128 yielded a peculiar radio signal. Further observations planned for Sunday night.

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.

Top tips for binocular stargazing

Whether you’re a beginning stargazer or a veteran of thousands of starry nights, binoculars can be your best friend.

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.

A universe of organisms living in your gut

Trillions of microorganisms living in your digestive system might influence your health, mood, even your weight.

Gender, racial bias in astronomy revealed

Research has found that women generally experience subtle, indirect or unintentional discrimination in the sciences. A new survey shows women of color undergo the worst harassment.

Today in science: 1st Telstar launch

Telstar was the 1st satellite to relay television signals between Europe and North America. It launched on this date … and helped change the world.  

Make a pinhole projector for eclipse-watching

You don’t need fancy equipment to watch a solar eclipse. This video shows you how to make a pinhole camera with just a few simple supplies.

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.

Do you have what it takes to live on Mars?

If it’s your dream to travel to the Red Planet, check out this video for some things you might want to consider.

How fireworks get their colors

The beautiful colors in fireworks – so good at stirring our emotions – are pure chemistry.