Mercury is the closest planet to the Sun and has a diameter of 3,031 miles. Struggling to lose weight? Give Mercury a try. A 100 lb person on Earth would weigh 34 lbs on Mercury, thanks to its lack of atmosphere.
You'll need to know about the Sun, asteroids, comets, and more to pass this stumper!
Crazy inventors think up something for everything. See if you can decipher these inventions.
Take this quiz to find out just how obsessed you are!
Sleep disorders leave you groggy, irritable and in a general bad mood. They also take a toll on your health. Find out if you have one.
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