The Moon's gravity is only about 1/6 as strong as Earth's gravity. So an object or person on the Moon would weigh about 1/6 of what it does on Earth. A 150 lb person on Earth would weigh around 25 lbs on the lunar surface.

The piano was invented by Italian harpsichord maker Bartolomeo Cristofori in the early 1700s. It was originally called the "pianoforte" because it could play both soft and loud dynamics, unlike the harpsichord.

Gregor Mendel, an Austrian monk, discovered the fundamental laws of inheritance through his work on pea plants. His experiments laid the foundation for the field of genetics.

"The Hobbit" was published in 1937 as a children's fantasy novel. Its success led Tolkien's publishers to request a sequel, which eventually became "The Lord of the Rings".

The six official languages of the United Nations are Arabic, Chinese, English, French, Russian and Spanish. These languages are used for meetings and official UN documents. Over half of the world's population speaks at least one of these as their native language.

Mary Shelley originally published "Frankenstein" anonymously because she feared the novel would not be taken seriously if people knew it was written by a woman, due to prejudice against female authors at the time.

In Greek mythology, Hades was the ruler of the underworld and the god of the dead. He was one of the six children of the Titans Cronus and Rhea, along with his brothers Zeus and Poseidon, who ruled the skies and the seas respectively.

Sally Ride became the first American woman in space when she flew on the Space Shuttle Challenger on June 18, 1983. She was the third woman overall to fly to space, after Soviet cosmonauts Valentina Tereshkova and Svetlana Savitskaya.

The Amazon rainforest covers over 2 million square miles across nine countries in South America, representing over half of the planet's remaining tropical rainforests. It is home to an estimated 10% of all known species on Earth and plays a crucial role in regulating the global climate and water cycles.

Friends ran from 1994 to 2004 on NBC. The series finale was watched by 52.5 million American viewers, making it the fifth most-watched series finale in television history.