The Solar System

Unlock the mysteries of Mercury Retrograde, its impact on astrology, and how to navigate its cosmic waves for personal growth.

By HowStuffWorks

Delve into the Earth's layers: crust, mantle, outer core, and inner core. Discover the secrets beneath our feet and the dynamic processes at play.

By HowStuffWorks

Explore the mysteries of the outer planets: Jupiter, Saturn, Uranus, and Neptune. Dive deep into their atmospheres, moons, and unique phenomena.

By HowStuffWorks

Nothing lasts forever. Does that include our home planet, too?

ByShichun Huang

Sometimes hundreds of people armed with high-tech cameras can make amazing scientific discoveries, as in the case of STEVE.

ByJesslyn Shields

March's full moon is called the worm moon for an unusual reason. What are some other names for the March moon and when can you see it?

ByValerie Stimac

Every 24 hours, Earth makes a full rotation on its axis. But why does Earth spin in the first place?

BySilas Laycock

Researchers at Australian National University studied 5,000 star-eating behemoths to find out.

ByChristian Wolf

January's moon is called the wolf moon, but it's also known as the center moon and the freeze up moon (among other names). Here's why.

ByValerie Stimac

All of the planets in the solar system are named for Greek gods, except Earth. So where did the name come from?

ByMark Mancini

Why do planets in the solar system all seem to be round? Why not cylindrical? Or even cube-shaped?

ByMark Mancini

在黑暗的空间中,我们安慰oon, the circular inspirer of song lyrics, poetry, and wannabe astronauts. But what do you really know about the moon and its history? Take this quiz to find out.

ByNathan Chandler

Those stars twinkling in the nighttime sky may actually be crystal spheres. And our beloved star is headed in that direction, too. Eventually.

ByIan O'Neill, Ph.D.

A massive planet 10 times the size of Earth seems to have been lurking on the edge of our solar system for some time now. How come we never noticed it before?

ByPatrick J. Kiger

Killer asteroids are all fun and games -- until they're headed for Earth. How do we stop cosmic hot potatoes from wiping out our planet?

ByWilliam Harris

It's not a pleasant thought, is it? But when you mix chaos theory with a few crazy cosmologists, those tidy, predictable orbits start getting lively.

ByWilliam Harris

Sunspots are peculiar dark areas that show up regularly on the surface of the sun -- and often for no reason. What causes them? What effect could these funny little spots have on the Earth?

ByPatrick J. Kiger

Hundred of meteors fly across the sky every night, but only a few make it to Earth. Meteors are best known for the brilliant streaks of light they make as they burn up in the atmosphere. Learn about 10 memorable meteor crashes that left an impression.

Bythe Editors of Publications International, Ltd.

We know it's not made of green cheese, but what are the origins of the moon? Learn astronomers' theories about where the moon came from.

ByTracy V. Wilson

Why does the moon look so much bigger when it is near the horizon than when it is high up in the sky? This question has been pondered for hundreds if not thousands of years, and is commonly referred to as the moon illusion.

You know Saturn and Venus and Mars. Can you put the eight planets of the solar system in the correct order? There are several ways to do this.

ByValerie Stimac

Scientists have observed flashes of X-rays coming from behind a supermassive black hole, consistent with Albert Einstein's prediction that extremely large objects can bend light.

ByPatrick J. Kiger

The gegenschein, "faint light" in German, occurs under very specific astronomical conditions when the sun reaches the exact opposite of Earth from wherever you're stargazing.

ByValerie Stimac

The Mars solar conjunction occurs every two years and forces NASA to stop communicating with assets on the Red Planet. So what's the deal?

BySharise Cunningham

Early dark energy, a form of dark energy that may have existed a few hundred thousand years after the big bang, could help clarify the universe's rate of expansion. But its existence hasn't been proven.

ByPatrick J. Kiger