24 June 2014, 01:42 PM ET
Mustangs were first brought over to the Americas by Spanish explorers.
23 June 2014, 06:26 PM ET
Medical marijuana is legal in some states, but debate rages on about whether the health benefits outweigh the risks.
23 June 2014, 05:35 PM ET
Marijuana produces a range of psychological and physical effects that can be unpredictable at times.
21 June 2014, 12:13 AM ET
The Mongolian Death Worm is said to be a large creature with spikes and acidic spit.
20 June 2014, 03:37 PM ET
There are more than 3,000 species of snakes in the world and there is at least one type of snake on every continent except Antarctica.
19 June 2014, 11:20 PM ET
Jaguars are large cats that can be found in North, Central and South America. They are identified by their yellow or orange coats, dark spots and short legs.
12 June 2014, 01:38 AM ET
Kinetic energy is the energy of mass in motion. The kinetic energy of an object is the energy it has because of its motion.
11 June 2014, 12:23 AM ET
A proof is a rigorous argument that shows a mathematical claim to be true. Arguments that are proven become theorems, such as the Pythagorean Theorem.
11 June 2014, 12:05 AM ET
“Earth science” is a broad term that encompasses four main branches of study — geology, meteorology, oceanography and astronomy — each of which is further broken down into more specialized fields.
10 June 2014, 10:41 PM ET
Hamsters are small rodents that are commonly kept as house pets.
09 June 2014, 08:07 PM ET
Wolves are large carnivores — the largest member of the dog, or Canid, family. Wolves are common to all parts of the Northern Hemisphere.
06 June 2014, 02:58 AM ET
The Vandals were a “barbarian” Germanic people who sacked Rome. The name has become a synonym for destruction.
05 June 2014, 05:56 PM ET
Rabbits are small mammals with fluffy, short tails, whiskers and distinctive long ears. There are about 30 species of rabbits around the world.
05 June 2014, 03:02 AM ET
Removing a tick correctly can lessen the chance of contracting a tick-borne illness.
03 June 2014, 02:52 PM ET
Camels are mammals with long legs, a big-lipped snout and a humped back. There are two types of camels: dromedary camels, which have one hump, and Bactrian camels, which have two humps.
31 May 2014, 03:39 AM ET
Transistors are tiny switches that can be triggered by electric signals. They are the basic building blocks of microchips.
31 May 2014, 03:23 AM ET
In many ways, the history of civilization is the history of chemistry. Humans have always sought to identify, use and change the materials in our environment.
31 May 2014, 03:17 AM ET
Watermelons may be mostly water but these refreshing fruits are soaked with nutrients.
31 May 2014, 02:35 AM ET
Sweet potatoes are a surprisingly nutritious vegetable. They are especially high in vitamins A, C, E, and B6, fiber and manganese.
31 May 2014, 02:25 AM ET
About 40 million Americans suffer from seasonal allergies. The most common culprit is pollen.
30 May 2014, 01:18 AM ET
Chemistry is the study of matter, its properties, how and why substances combine or separate to form other substances, and how substances interact with energy.
29 May 2014, 11:12 AM ET
Manhattanhenge, a phenomenon when the setting sun is perfectly aligned with Manhattan's grid-patterned streets, occurs twice a year with a full sunset, and twice a year with a half sunset.
29 May 2014, 03:03 AM ET
Nikola Tesla is often called one of history’s most important inventors, one whose discoveries in the field of electricity were way ahead of his time.
29 May 2014, 02:54 AM ET
Prenatal genetic testing may diagnose any complications or developmental issues. It can be controversial, but also beneficial.
29 May 2014, 02:48 AM ET
The Goths sacked Rome in A.D. 410, but they also helped preserve Roman culture.
28 May 2014, 02:56 PM ET
There are more than 260 known species of monkeys in the world.
24 May 2014, 02:44 AM ET
No one has ever seen the moving rocks at Racetrack Playa, but the telltale trails indicate that the stones do shift.
23 May 2014, 10:27 AM ET
Foxes are found all over the world. In folklore, foxes are typically characterized as cunning creatures sometimes having magical powers.
22 May 2014, 08:13 PM ET
Potatoes are often thought of as a comfort food — richly mashed or crisply fried — but when prepared the right ways, these vegetables are actually quite nutritious.
21 May 2014, 03:31 PM ET
Sloths spend most of their time sleeping and eating in the tropical rainforests of South and Central America.
21 May 2014, 11:14 AM ET
Great masses of flesh that wash up on shore have mystified people for centuries. Tests show that they aren't actually sea monsters.
21 May 2014, 12:38 AM ET
The Gregorian calendar — used by most of the world — was introduced to fix errors in the Julian calendar mostly having to do with leap years.