Nobody is credited for the discovery of Mars. However one cool fact about Mars is that like Venus, it’s visible with the naked eye.

Radium was discovered in 1898 by French physicist and Nobel laureate Marie Curie.

Gravity was discovered by the scientist Sir Isaac Newton.

Sulfur was discovered by Henning Brand in 1669. It was identified by Antoine Lavoisier in 1777.

X-rays were discovered in 1895 by Wilhelm Conrad Röntgen.

Electricity has always been around the world. The Ancient Greeks discovered that rubbing fur on amber caused an attraction between the two. Benjamin Franklin is considered the father of electricity. In 1752 he established a relationship between lightning and electricity, which led to the invention of the lightning rod. Later, in 1800, Alessandro Volta constructed the voltaic pile. Michael Faraday created the electric dynamo and Thomas Alva Edison invented the light bulb (1879).

Iron has been used since prehistory. So nobody knows who really discovered it. However like in the picture above huge mountains made of iron ore are mined every day!

Planet Uranus was discovered by William Herschel on March 13, 1781. He also discovered two of the moons of Uranus. Uranus is the first planet discovered with a telescope.

There is not sure who discovered Jupiter first. However, Galileo Galilei discovered in 1610 four of the Jupiter’s moons. These are called Io, Europa, Ganymede and Callisto.

The symptoms of pneumonia were described by Hippocrates. (c. 460 BC–380 BC). The discovery of X-rays allowed doctors to find the anatomic type of pneumonia.