Original artworks from NASA

While there is much debate over which exoplanet discovery is considered the "first," one stands out from the rest. In 1995, scientists discovered 51 Pegasi b, forever changing the way we see the universe and our place in it. The exoplanet is about half the mass of Jupiter, with a seemingly impossible, star-hugging orbit of only 4.2 Earth days. Not only was it the first planet confirmed to orbit a sun-like star, it also ushered in a whole new class of planets called Hot Jupiters: hot, massive planets orbiting closer to their stars than Mercury.

The National Aeronautics and Space Administration is an autonomous organization of the United States Federal Government liable for the regular citizen space program and aeronautics and space research. NASA was set up in 1958, succeeding the National Advisory Committee for Aeronautics (NACA). Since its foundation, most US space investigation endeavours have been driven by NASA, including the Apollo Moon landing missions, the Skylab space station, and the Space Shuttle.