Earth Science

Cinnabar's bright-red pigment has been used in jewelry, pottery and makeup for millennia. But cinnabar is also the primary ore for mercury, making it a dangerous mineral if the particles are inhaled.

By Allison Troutner

There are caves all over the world, but some are in places that are hard to explore — hidden by rocks, ruins or even under ice. We've found seven secret caves you probably never knew existed.

By Stephanie Parker

The waters of the Atlantic and Pacific oceans meet at the tip of Cape Horn and never the two shall mix, right?

By Jesslyn Shields

The Atlantic Meridional Overturning Circulation, or AMOC, plays an essential role in regulating ocean temperatures, but it looks as if it may be collapsing. What happens next?

By Joanna Thompson

This ancient rock adorns King Tut's coffin and the Sistine Chapel. And at one time it was more precious than gold. What is it about this deep blue rock that has drawn us in for centuries?

By Carrie Whitney, Ph.D. & Austin Henderson

It's possible that the giant, deadly serpent hanging out at the bottom of Fosse Dionne spring is just a legend, but divers have disappeared trying to find out, so who knows?

By Jesslyn Shields

The curves of the Serpent Mound, Ohio state's massive and mysterious geological wonder, line up with the sun during equinoxes and solstices.

By Jesslyn Shields

The rose-red mineral rhodonite was first discovered in the 1790s in the Ural Mountains of Russia. Today it's found globally and is associated with compassion, love and healing.

By Allison Troutner

Waterfalls are mainly reliant on precipitation to keep flowing. Here are six famous waterfalls that slowed to a trickle when drought set in.

By Laurie L. Dove

Deep underneath Antarctica, there lies a hidden lake. Roughly the size of North America's Lake Ontario, the buried landmark has inspired curiosity and controversy for decades.

By Mark Mancini

Some say UFOs, while others say a meteor strike formed the Carolina Bays. Whatever created these isolated ponds and wetlands across North and South Carolina left a wondrous ecosystem that is in dire need of protection.

By Allison Troutner

The dead zone, caused by massive amounts of algae growth, is a vast area off the Gulf of Mexico that is deadly to marine life. How is human activity making the dead zone worse?

By Jacob Silverman

Anyone who's been to the ocean has probably seen the foamy white stuff that clings to the sand after a wave breaks and recedes, but what the heck causes that bubbly foam and is it dangerous?

By Kristen Hall-Geisler

How do they measure "sea level"? Is it the average of the tides? And is the sea level actually rising or not?

Let's say you have a lunch date to make – and it's on the other side of the planet. Wouldn't it be convenient to pop down a hole through Earth's innards? But what would really happen if you did?

By Nicholas Gerbis

You probably know that the North Pole does not stay in the same spot. The North and South Poles can actually change positions. What causes this? Find out in this article.

By Tracy V. Wilson

Diamonds are beautiful and popular - but not everyone can afford these gems. While man-made versions are less expensive, most lack the luster and brilliance of the real thing, except moissanite. See how it compares!

By Melissa Russell-Ausley

A seismograph can accurately measure the movement of the Earth during a quake. How does a seismograph work, though, and what is the Richter scale that is associated with earthquakes? Learn the answers to these questions in this article.

By Sascha Bos

Water is one of the most abundant substances on the planet. About 70 percent of our planet is covered by oceans, but just how much water is there on Earth?

By HowStuffWorks.com Contributors & Yara Simón

Gravity is a force that we experience every minute of our lives, but hardly notice or give a passing thought to in our daily routines. Have you ever wondered what gravity is and how it works? Learn about the force of gravity in this article.

By Julia Layton & Austin Henderson

The oceans are rising, and they're threatening to take down some of the world's brightest cultural gems. Here are 10 of the most notable spots endangered by climate change.

By Chris Opfer

There's still a lot we don't know about the world. A thousand years ago, we thought we could literally sail off the edge of the planet. Good thing we're quick learners. But while space may be the final frontier, the ocean may be the greater mystery.

By Kate Kershner

There's no denying it: "Anomaly" is a great word, full of danger and mystery. So when an underwater object is declared a bona fide anomaly, it's no surprise our ears perk up a bit. But is the Baltic Sea anomaly worth the hype or just a big old dud?

By Kate Kershner & Yara Simón

From the Hope diamond to the shiny bits in instant coffee, crystals have always held the power to fascinate us humans. Are they more than just a bunch of pretty facets?

By Nicholas Gerbis

You likely heard that paleontologists uncovered a cache of dinosaur embryos, bone fragments and eggshells in China. You also may recall that we've made crazy leaps forward in genetics and genomics. Can we put the two together and create a dinosaur?

By Nicholas Gerbis