Ununoctium
copper
The discovery of the element is credited to the German chemist Martin Heinrich Klaproth. While he was working in his experimental laboratory in Berlin in 1789. He found an uranium oxide (which he had named after the planet Uranus which had recently been discovered) in pitchblende ores. The pure element was isolated in 1841 by Eugene Melchior Peligot.
Gold was the first metal that people discovered, because it can be found in nature in its metallic form, as gold nuggests, as compared to other metals which need to be refined or smelted out of minerals. The discovery of gold is very ancient, going back to the neolithic period.
iron was first discovered about 4000 years ago
It would be most difficult to determine which explorer discovered the most land. However, Christopher Columbus discovered lands in Central America which is connected to both North and South America. So, it could be said that he "discovered" two continents that were previously unknown.
wind
Antarctica is the most recently discovered continent.
South Sudan which was founded on 9 July, 2011.
The latest confirmed element discovered was Livermorium, 116Lv, in 2000. Ununseptium is not officially credited as "discovered" by the IUPAC/IUPAP Joint Working Party, but it is the most recently synthesized element, made in 2010.
water was recently discovered on planet mars
Neptune was discovered on September 23rd, 1846.
buckyballs, buckytubes or nanotubes are the recently discovered forms of carbon from 1950s.
pulsar and quasars
plants
I don't know what you mean by "recently". It was discovered in the 1500's by the Spaniards.
That would be UB313, discovered in 2005,
about 403.