This is a great week for planetary observers. Mercury is in its best position as a "morning star" for observers in the Northern Hemisphere while Jupiter is at i

Spliced from thousands of screenshots of the planets, NASA has created a new video of Mercury that shows off the planet's diversity in terrain.

This week in the hour before sunrise early morning stargazers will get a double treat: the planet Mercury and two special comets.

For the next few weeks, about half an hour before sunrise, Mercury will peek over the southeastern horizon for observers in the northern hemisphere.

This devilishly difficult quiz will separate the auto experts from the pretenders.

Test your knowledge of the wild world of animal mating.

From what they eat to wear they live, test your giant panda knowledge with this quiz.

Crows and ravens are some of the smartest animals on the planet. So what do you know about them?

Whether you watch them at your backyard bird feeder or just see them when you're hiking, how much do you really know about our feathered friends?

What do you know about your kidneys? They don't get the acclaim of the brain or the heart, but these small organs work nonstop to keep your body healthy.

Test your knowledge about frogs and toads with this quiz.

You go to the beach to relax and soak up the sun. But how much do you really know about the waves and the sand?

How much do you know about these ancient shelled reptiles?

Before you scoop up your next bowl of ice cream, test your knowledge about everyone's favorite summer treat.

They help you see the world, but how much do you really know about the windows to your soul? Test your knowledge.

Can you live without your morning coffee or afternoon soda? See how savvy you are about your daily buzz.

When your head hits the pillow at night, do creatures lurk? See how much your know about terrifying dreams.

There's a whole medicine chest in the garden. Do you know which plants to use for what ailments? Test your holistic herb wits here.

How much do you really know about the ground under your feet? Test your knowledge with this quiz.

There are those of us who aced AP calculus, and there are those of who can't figure out the tip. Take our quiz to find out just how much of a math whiz you are.

Life across the globe depends on bees, butterflies, birds, bats and other pollinators. Test your knowledge about these vital creatures.

From spring showers to summer thunderstorms, rain can fall any time of year. But how does it work?

When a painting sells for a jaw-dropping price, it makes headlines. Do you know how much these works of art went for?

They're massive, they're all-natural and, in most cases, they're millions of years older than we are. So how were these amazing landforms created?

Bison have been named our new national mammal. Test your knowledge of this species that's so critical to North America's ecology.

These unusual creatures are stunningly beautiful and surprisingly important to life on Earth. Show us what you know!

Bacteria live everywhere in your body, including your gut. These microbes have quite an impact on your health. Do you know what they do?

Whether it's a white lie or a whopper, fibs are part of our daily lives. We like to think we're honest but, well, we're not. Test your falsehood expertise.

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?

From the cheetah to the hare, so many creatures are wickedly quick. Test your trivia smarts on what makes them so swift.

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

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

The 57,000-acre San Andres Refuge, which works to restore desert bighorn sheep, launched its quest for energy independence in 2005 and has implemented several s

Japan's plan to wean off nuclear power could help lead a global push toward cleaner, more efficient civilization, says U.S. energy guru Amory Lovins.

Whether it's fresh or canned, pumpkin freezes really well.

While easy to focus on the gross-out factor, the tale of a stranded train filled with sewage sludge shines a light on the complicated afterlife of our waste.

You may love Amazon Prime, but the environment doesn't.

Thanks to the 24-hour news cycle and social media, it's impossible to tune out these politically turbulent times. Here's how to tune in and stay sane.

The release, quickly dubbed "Climategate 2.0" after the initial 2009 "Climategate" hacking, drew strong condemnation from scientists involved in the emails, as

Innovative technology enables electronic devices to function in contact with body tissues.

Today's technology allows us to look deep into what was previously invisible, revolutionizing our understanding of microorganisms.

Sustainability played a key role at this year's CES with both the CEA and Bosch donating materials and funds to Habitat for Humanity green building efforts.

Pando, the world's largest-known organism, is dying. But there might still be time to save this wonder of nature.

Boxed wine is quick becoming a favorite of eco-friendly wineries and organic wine drinkers who are starting to love brands like yellow + blue.

Columnist Matt Hickman offers advice on how to get a crunchy-granola, green husband to wear underwear.

Chanie Kirschner helps an expectant mom focus on the things she can control.

Journalist Heather Rogers maintains that we can't buy our way out of the crisis our planet is experiencing.

Check out this infographic, which breaks down the importance of organic food, how mobile usage affects purchasing, food labels and more.

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.

From your blood pressure to your vision, here's how barometric pressure might affect you.