The Solar System

Head's up, stargazers! Mark your calendars for the 22 must-see events this year.

By Martha Sandoval

News headlines talk about a rare green comet appearing in the sky. The comet itself is rare, but green comets, not so much. What makes some comets appear green?

By Valerie Stimac

February is a cold time of year, and the snow moon nickname pays homage to that. What are some other names for February's full moon and what do they mean? Plus, when can you see the snow moon?

By Melanie Radzicki McManus

April's pink moon isn't called pink because our beloved bright white moon suddenly takes on a rosy hue. So, why is it called the "pink moon"?

By Valerie Stimac

Native American tribes have called the May moon the flower moon for centuries. The name even inspired a best-selling novel and film.

By Valerie Stimac

The full moon in June is known as the strawberry moon. It's a sweet name, but how did the strawberry moon get its moniker, and what else is it called?

By Melanie Radzicki McManus

There are eight phases in the lunar cycle and the moon is in one of them every night. What are these phases of the moon?

By Valerie Stimac

The solar system's largest planet will pass closest to Earth at the same time it's at opposition. That means it will be the biggest and brightest it's been in the sky in decades.

By Patty Rasmussen

In 2022, the full moon, called the hunter's moon, will occur Oct. 9. Why is it called that and when can you see it?

By Valerie Stimac

As the search for Planet Nine wears on, and astronomers have yet to get so much as a glimpse of it, researchers are pondering what else the object might be.

By Ian O'Neill, Ph.D.

The Geminid meteor shower is one of the year's stronger displays in terms of number and size of meteors. When's the best time to see it?

By Christopher Hassiotis

The moon has seen a lot in its 4.5 million years of life, and this detailed geologic map serves as testament.

By Jesslyn Shields & Yara Simón

In 1953, CalTech geochemist Clair Patterson came up with an estimate for Earth's age that still holds today.

By Patrick J. Kiger

Check out this video of what astronauts in space see as the shadow of the moon crosses our planet.

By Christopher Hassiotis

And don't worry. Even if NASA misses, we'll be fine.

By Ian O'Neill, Ph.D.

Every autumn, Earth passes through a stream of debris left by Halley's comet, resulting in some beautiful nighttime meteor showers called the Orionids. Here's what to watch for.

By Patrick J. Kiger

Everyone's heard of the blue moon and the harvest moon, but every other full moon of the year has a name, too. What are their names, and when do these moons occur?

By Nathan Chandler

But what?

By Ian O'Neill, Ph.D.

Researchers at the Zwicky Transient Facility have found an asteroid in Earth's orbit. And this one has the shortest year yet.

By Ian O'Neill, Ph.D.

Did you know that a moon can leave its orbit around a large planet and go out on its own?

By Patrick J. Kiger

Back in 2006, the International Astronomical Union decided to demote Pluto to the status of a dwarf planet. A historical study challenges that designation.

By Patrick J. Kiger

Astronomers have just discovered a gas in Uranus' clouds that does nothing to help the planet being taken seriously.

By Ian O'Neill, Ph.D.

And if we're going to get technical about it, neither do those of us here on Earth.

By Christopher Hassiotis

Energized subatomic particles bombarding Earth from outer space can cause the electronics inside laptops, cell phones and other devices to crash.

By Patrick J. Kiger

How galaxies get their shapes and evolve is widely debated.

By Mark Mancini & Yara Simón