Coppernicium, Cn, (proton number 112) was discovered 15 years ago, added to the periodic table two years ago but is still relatively unheard of.
The reason why it is relatively unheard of is the fact that it is man made and extremely radioactive. The most stable isotope only has a half life of four minutes.
Image reproduced according to the licence at: http://en.wikipedia.org/wiki/File:Nikolaus_Kopernikus.jpg
It is named after Nicolaus Copernicus, who, in 1543 published the book ‘De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres)’ which is arguably one of the most important scientific pieces of literature every released.
It seems ironic that the man who changed our views of the heavens, stars and ultimately time itself is remembered through a minuscule and short lived atom! 😯