The Fact Ledger

A day on Mars lasts 24 hours, 39 minutes, and 35 seconds.

Mars spins on its axis at nearly the same speed as Earth. This makes a Martian day, called a sol, only about 40 minutes longer than an Earth day.

The Titanic had an older sister ship called the Olympic that looked almost exactly like it and sailed for 24 years.

The Olympic was the first of three giant ships built to be the most luxurious in the world. While the Titanic sank on its first trip, the Olympic completed hundreds of successful j...

The first skyscraper used a metal skeleton to stand 10 stories tall in 1884.

Before this, tall buildings needed thick stone walls to stay up. Architect William Le Baron Jenney used a steel and iron frame to hold the weight instead of the walls.

A single pineapple plant takes up to two years to grow just one fruit.

The plant must grow dozens of leaves and a strong root system before it can produce a flower. This flower eventually develops into the pineapple we eat.

Outer space is not empty; it is filled with a thin soup of gas, dust, and radiation.

A perfect vacuum contains nothing at all. Space contains stray atoms and energy left over from the beginning of the universe. Even the emptiest parts of space have about one atom i...

Antarctica is the largest desert on Earth and is nearly twice the size of Australia.

Deserts are defined by how little rain or snow they get, not by how hot they are. Antarctica is the driest continent because its interior receives less than 2 inches of water per y...

The song 'You Suffer' by Napalm Death is the shortest song ever recorded, lasting only 1.316 seconds.

The song contains only four words: 'You suffer, but why?'. The band wrote it to mock the idea that songs need to be long or complicated.

The Statue of Liberty was an official lighthouse for 16 years.

President Grover Cleveland designated the statue as a navigational aid in 1886. It was the first lighthouse in the United States to use electricity. The light was eventually shut d...

White chocolate is not technically chocolate because it contains no cocoa solids.

Cocoa solids give chocolate its brown color and deep flavor. White chocolate uses cocoa butter instead, which is just the fat from the bean.

High heels were originally created for Persian soldiers to help them stay on their horses.

The heels locked into stirrups so riders could stand up and shoot arrows without slipping. This footwear was a tool for war long before it became a fashion choice.

The clouds on Uranus smell like rotten eggs.

The planet's upper atmosphere contains a gas called hydrogen sulfide. This is the same chemical that makes spoiled eggs and flatulence smell bad.

Hyperion is a coast redwood in California that stands 380.1 feet tall, making it the tallest living tree on Earth.

The tree grows in a secret spot in Redwood National Park to keep it safe. If too many people walk near it, they pack the soil down and damage its shallow roots.

The human body contains enough iron to make a metal nail 3 inches (7.5 cm) long.

An average adult has about 3 to 4 grams of iron in their body. Most of this metal is inside red blood cells, where it helps carry oxygen to your organs.

Sunsets on Mars look blue, while the daytime sky is a pinkish-red color.

Fine dust in the Martian atmosphere scatters light differently than the air on Earth. This dust blocks red light near the sun at sunset and lets blue light pass through to your eye...

Ancient Romans used human urine to wash their clothes.

Urine contains ammonia, which is a natural cleaner that breaks down grease and stains. Roman laundry workers collected urine from public toilets and used it to whiten woolen togas.

Bottlenose dolphins have unique names for each other called signature whistles.

Each dolphin creates its own special sound during its first year of life. They use these sounds to identify themselves and call out to specific friends or family members.

A group of giraffes standing still is called a tower.

When giraffes move together, the group is called a journey instead. Their height helps them see predators from far away. Standing in a group allows them to watch in every direction...

Smiling can make you feel happier even if you are faking it.

Moving your facial muscles into a smile sends a signal to your brain. Your brain then releases chemicals that improve your mood and lower stress.

Ruth Wakefield invented the chocolate chip cookie in 1938 when she added broken chocolate pieces to dough, expecting them to melt.

She ran out of baker's chocolate and used a Nestlé semi-sweet bar instead. The chocolate chunks stayed solid instead of mixing into the dough, creating the first chocolate chip coo...

Energy cannot be created or destroyed, only changed from one form to another.

The total amount of energy in the universe always stays the same. A car engine does not make new energy. It turns the chemical energy stored in fuel into heat and movement.

The first permanent movie theater opened in Pittsburgh in 1905 and cost only five cents to enter.

Before this, people watched movies at traveling carnivals or temporary shops. This theater was so popular that it proved movies could be a successful full-time business.

"I am" is the shortest complete sentence in English that includes both a subject and a verb.

A complete sentence needs a person or thing doing an action. In this sentence, "I" is the person and "am" is the action. Other short sentences like "Go!" are shorter but do not nam...

Ancient civilizations used water clocks to tell time by measuring the steady flow of liquid into or out of a container.

These devices used gravity to pull water through a small hole at a constant speed. People tracked the time by looking at marks on the container that showed how much water had moved...

Pluto has not finished a single orbit around the Sun since humans discovered it in 1930.

It takes Pluto 248 Earth years to complete one full trip. Because it is so far away, it moves slowly and has a very long path to travel.

Ray Tomlinson sent the first email between two different computers in 1971 and chose the '@' symbol to separate the username from the computer name.

Before this, people could only leave messages for others using the exact same computer. Tomlinson used a network called ARPANET to move digital messages from one machine to another...

A group of sharks is called a shiver.

Most sharks hunt alone, but they sometimes gather in large groups to eat, mate, or migrate. These groups can include hundreds or even thousands of sharks in one area.

Strawberries contain more Vitamin C than oranges when comparing equal weights.

One hundred grams of strawberries have about 58.8 milligrams of Vitamin C. The same weight of oranges has about 53.2 milligrams. Eating eight large strawberries gives an adult thei...

You lose between 50 and 100 hairs from your head every single day.

Each hair on your head grows for a few years and then takes a break. When a hair follicle rests, the old hair falls out so a new one can grow in its place. Since you have about 100...

Ice cream was once a rare luxury that only royalty and the very wealthy could afford.

Before refrigerators existed, people had to harvest ice from frozen lakes in the winter. They stored it in deep underground pits to keep it from melting until summer. This process...

A single banana is called a finger, and a small cluster of them is called a hand.

A large group of bananas growing on a plant is called a bunch. One bunch can hold up to 20 hands, which means it can have 200 individual fingers.

Chuck Norris was born with the name Carlos Ray Norris.

He received the nickname Chuck while serving in the United States Air Force. He kept the name when he started his career as a martial artist and actor.

Chuck Norris has written several New York Times bestselling books.

He is known for martial arts and acting but is also a successful author. He has written his life story, novels, and books about his personal beliefs.

The famous fight between Bruce Lee and Chuck Norris in the movie Way of the Dragon was filmed in a studio, not the Roman Colosseum.

Italian laws prevented the crew from filming a long fight scene inside the real Colosseum. The filmmakers took photos of the landmark and built a matching set at a studio in Hong K...

Chuck Norris started a program that teaches karate in middle schools to help kids build character.

The program is called Kickstart Kids. It uses martial arts to teach students discipline and respect during their regular school day. This helps them stay away from trouble and focu...

Chuck Norris started learning martial arts while working as a police officer for the U.S. Air Force in South Korea.

He was stationed at Osan Air Base in 1958 and found the physical training difficult. He began practicing a local style called Tang Soo Do to get stronger and more disciplined.

Monowi, Nebraska, is the only town in the United States with a population of just one person.

Elsie Eiler is the only resident and holds every government job. She is the mayor, clerk, and treasurer. She even votes for herself in every election.

A violin called the 'Lady Blunt' sold for $15.9 million in 2011, making it the most expensive musical instrument ever sold at a public auction.

Antonio Stradivari built this violin in 1721. It is valuable because it is in nearly perfect condition. Most old violins show wear from centuries of use, but this one was kept by c...

Albert Einstein was offered the job of President of Israel in 1952.

Israel's first president died and the government wanted a famous leader to take his place. Einstein turned down the offer because he believed he was not good at working with people...

Mount Everest grows about 4 millimeters taller every year.

The mountain sits on two giant pieces of the Earth's crust called tectonic plates. These plates are slowly crashing into each other and pushing the land upward.

Pizza Hut delivered a six-inch salami pizza to the International Space Station in 2001.

The pizza traveled on a Russian rocket to reach the astronauts. It was a marketing project that took a year of planning with space scientists.

Alaska is the northernmost, westernmost, and easternmost state in the United States.

The 180th meridian is the line that separates the Eastern and Western Hemispheres. Because some of Alaska's islands cross this line, they are technically located in the Eastern Hem...

Many oysters start their lives as males and later change their biological sex to female.

This change helps the oyster colony survive. Larger oysters become female because they have more energy to produce millions of eggs.

The world's first gas station was a pharmacy in Wiesloch, Germany.

In 1888, Bertha Benz stopped at this pharmacy to buy fuel during the first long-distance car trip. At the time, gasoline was sold in small bottles as a cleaning fluid.

Corn Flakes were first sold under the name Sanitas Toasted Corn Flakes.

The name Sanitas comes from the Latin word for health. Doctors created the cereal as a plain food for patients at a health spa in Michigan.

The winner of the 1904 Olympic marathon used rat poison and brandy to finish the race.

Trainers gave Thomas Hicks small doses of strychnine and alcohol because they thought it would boost his energy. This mixture is actually toxic and nearly killed him by the time he...

Dolphins sleep with only half of their brain at a time.

Dolphins must choose when to breathe, so they cannot fall completely asleep. One half of the brain stays awake to control breathing and watch for sharks while the other half rests.

An object in space will move in a straight line at the same speed forever unless something hits it or pulls on it.

This happens because of inertia. Objects naturally resist changes to their movement. On Earth, things slow down because invisible forces like air and friction push against them.

Venus is the hottest planet in our solar system with a surface temperature of 864°F (462°C). This temperature is high enough to melt lead.

Venus has a thick atmosphere made of carbon dioxide that traps heat. This gas acts like a heavy blanket that prevents heat from escaping into space. Even though Mercury is closer t...

Ancient Roman gladiators were mostly vegetarians who ate a diet of barley and beans.

This diet was high in carbohydrates. It helped fighters grow a thick layer of body fat to protect their organs from shallow sword cuts.

Some parts of the Atacama Desert in Chile have not seen a single drop of rain for over 400 years.

Two mountain ranges block all wet air from reaching the desert. This creates a double rain shadow that keeps the ground completely dry.