Jupiter has more than 60 moons. The four largest—Io, Europa, Ganymede, and Callisto—were the first satellites of a planet other than Earth to be detected. They were discovered by Galileo in 1610, shortly after he invented the telescope, and are therefore known as the Galilean satellites. On January 7, 1610, Galileo observed near Jupiter what he described at the time as “three fixed stars, totally invisible by their smallness.” How long did it take Galileo to discover the fourth? Discuss
Source: The Free Dictionary
An anthropologist, folklorist, and author, Hurston spent much of her life collecting African-American folktales in the rural South and in other places, such as Haiti, Bermuda, and Honduras. She was a significant figure in the Harlem Renaissance and collaborated with her friend Langston Hughes on the play Mule Bone in 1931. Along with her folklore collections, she also wrote four novels, including the influential Their Eyes Were Watching God. Why did the book inspire controversy? 
Burden is a performance artist who emerged as part of the American art scene in the 1970s, performing controversial, dangerous pieces in which he used his own body as the art medium. During a 1971 performance piece titled Shoot, he was shot in his left arm by an assistant standing a short distance away. He was labeled insane following the performance, but it has since become one of his most well-known pieces from the period. Why did he resign from the University of California in 2005? 
In 1832, Morse, an American painter-turned-inventor, began working on a system for transmitting messages as electrical pulses across a wire. Five years later, he was granted a patent for his electromagnetic telegraph, and he successfully tested the device a year after that. Public use of Morse’s telegraph system, as well as the code he developed to represent letters and numbers as electrical pulses, began in 1844 and lasted over 100 years. What was the first message sent on the public system? 
Each year on January 6, the 
Richard II was perhaps the most enigmatic of the English kings, reigning from 1377 to 1399. He inherited the throne as a boy, but his uncle John of Gaunt and other nobles dominated the government, limiting his power. Taking revenge, he banished John’s son, Henry, and confiscated his vast Lancastrian estates. Not long after, while Richard was away on an expedition, Henry returned and seized power. Forced to abdicate, Richard was imprisoned and died in captivity. What likely caused his death? 
The pituitary, thyroid, and adrenal glands are all part of the endocrine system, a bodily system that is instrumental in regulating metabolism, tissue function, and growth and development. The endocrine system is an integrated network of small glands located throughout the body that release extracellular signaling molecules known as hormones. Hormones travel in the blood to distant targets, where they cause specific physiological responses. What diseases result from endocrine system problems?