Hiv/aids
Ununoctium
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,