Articles

Stories, updates, insights, and original analysis from The Planetary Society.

Earthrise by Lunar Reconnaissance Orbiter

How old is the Earth?

The Earth is thought to be about 4.54 billion years old. Learn more about how it formed, and how we know when this all happened.

What would happen if an asteroid hit the Moon?

If a large asteroid impacted the Moon, would it cause problems for us here on Earth?

Storms and showers

Mars has storms of dust, while Saturn pours down ammonia rain. Here on Earth, we passed through a debris tail to get a special kind of shower.

Hasta la vista, baby

Terminators abound this week in space, and we’ll be back to Mars if NASA gets the budget it needs.

Moon-spying missions and a planetary evil twin

Whether they’re dedicated to it or not, planetary missions can get beautiful and informative glimpses at distant moons. And who’s the evil twin: Venus or Earth?

Hard-working spacecraft and even harder-working microbes

The Soyuz spacecraft have been helping humans get to and from space for decades, but that’s nothing compared to the billions of years that microorganisms have been making life on Earth possible.

How did Earth get its oxygen?

A tiny, Sun-loving microbe has made a very big impact on our atmosphere.

What does “Mercury in retrograde” actually mean?

"Mercury in retrograde" is one of the most searched terms relating to the planet. Astrological interpretations aside, apparent retrograde motion is an interesting phenomenon that has to do with orbital speeds and observer perspective.

What the search for aliens can learn from life on Earth

When searching for extraterrestrial life, we have to base our hunt on what we know about life on our own planet. This may seem limiting, but there's a lot we can learn from the astonishingly diverse lifeforms we have here on Earth.

A long night, and “so long!” to InSight

Celebrate the December solstice, be thankful you’re not on Triton, and say goodbye to the InSight Mars lander.

Capturing the Cosmos

This week we have images snapped the old-fashioned and cutting-edge ways, creative ways of thinking about exploration, and artwork that expresses the beauty of it all.