The Earth's mountains, rivers, animals and rocks have been around for millions or billions of years. Do you know which ones have been around the longest?

National Park and Earth Week are right around the corner — see how much you know about our nation's protected areas.

Whether you're crying tears of joy or crying over spilled milk, how much do you really know about the tears rolling down your face?

Lightning is more than just a stunning spectacle. Take our quiz to see how much you really know about this electrifying natural wonder.

Think you know everything about that special day of scary movies and sugar highs? Test your Halloween smarts ... if you dare.

You use pasta in sauce, in soups and in salads. But do you know the names of the different pasta types?

When the going gets tough, some animals get going — to bed. Take our hibernation quiz to see how much you know.

Every two years, the National Science Foundation asks 10 questions to see how much Americans know about science.

When it comes to decisions on electricity and energy policy, women do not have the facts they need.

Intel's Compute Stick turns your big TV into a working Windows computer.

Even though native bees don't produce honey, they're incredibly important, says author Paige Embry. She explains how to help them in "Our Native Bees."

Famed naturalist and conservationist John Muir was so much more than the father of our national parks.

There are lots of causes for sleepless nights, but it helps to know if it's insomnia or not. Thankfully, there are natural ways to get back on track.

What is Lyme disease? Here's where you are more likely to get it and the symptoms to look for if you're concerned.

In honor of Cesar Chavez Day, here are 10 interesting facts about the civil rights activist.

From their vanilla-scented secretions to their amazing ability to alter an ecosystem, here's what you need to know about beavers.

Reality can never be perfectly simulated if you take into consideration quantum complexity.

Test your knowledge of where products come from and find out if you're a savvy consumer by taking this Made in the USA quiz.

Forthcoming documentary follows movement to link poor growers with roasters and consumers.

A new study finds dogs rush in — but stay calm — when they hear their human crying.

The flu vaccine is your best weapon against the flu this year.

Health officials have identified a 'very strong culprit' for the devastating sickness linked to e-cigarettes.

Colorado and Washington state have legalized marijuana, and others are considering measures. Test your cannabis knowledge.

They might just kill a few sites that you know and love.

A new U.S. report on climate change offers 'information that every human needs.'

The EPA has unveiled a plan to limit carbon emissions from new coal-fired power plants. Here's a look at what the rules could mean.

Father-daughter team turns a common race practice into a clever opportunity to help the less fortunate.

A once-'mild' virus found in Africa 70 years ago is now running wild. Here's everything you need to know.

NASA aims to launch a flight test Thursday, June 4, of an innovative "flying saucer" that could help humans land on Mars in the future.

The European Space Agency's ExoMars mission is a two-phase operation that will look for methane, ice and landing sites for future rovers.

Finding water ice could change everything we thought we knew about the red planet, and make colonization feasible.

Palm oil's effect on the environment and the people directly and indirectly involved with its creation is detrimental. Here are some of the issues.

The new U.S. plan to limit power plant emissions is 645 pages long. Here's what you need to know.

The new U.N. climate agreement is being called 'a monumental triumph' and 'a turning point for the world.' Here are a few key points to keep in mind.

Facebook knows who your romantic partner is, even if you keep that information private, and can even predict if the relationship will last.

The idea grew out of disaster message boards that sprung up on Facebook after Japan's most recent natural disaster.

New research shows that just clicking the 'like' button reveals more about us than we realize.

If you see this tagline on your teen's social media pages, here's what's going on.

A survey of general scientific knowledge found that Americans aren't so science-savvy. How will you do?

Aerosol air fresheners contribute to, rather than reduce, indoor air quality problems. And they often contain toxic chemicals like formaldehyde and xylene.

Animals use the same wait-your-turn system that most humans do, say scientists who reviewed a series of animal studies.

Hydraulics give a British backyard potting shed a lift when needed.

From animal welfare to marine protection to climate change, these environmental charities are sure to put your money to good use.

New campaign hopes to help consumers see the light on energy-saving light bulbs.

This weekend, before your kids hit the baseball and softball fields, read about how energy and sports drinks can damage tooth enamel, plus take a look at a few

Are you qualified to recite the Girl Scout promise? Prove it.

The U.S. representative fighting for her life after a weekend shooting has been an advocate for many issues, including the environment.

In honor of American Made Matters Day, we rounded up 10 products manufactured in the U.S.

Almost 50 years after Aldrin ate oatmeal on Apollo 11, Quaker uses his breakfast of choice in an inspirational ad not aired in the U.S.

Epicurious picks the 100 greatest home cooks of all time, and you might be surprised by the names on the list.