That's a really hard one to answer. If you are talking about historical or "famous" figures in astronomy, it would depend on the list provided.
If you are talking about who made the latest contribution in general, well there are tons of papers constantly being published, so it will change frequently.
As one of the sciences astronomy is most closely related to mathematics, physics and chemistry.
aristotle, copernicus, galileo
Historically, it was the optical telescope. Modern radio telescopes, and cameras mounted on satellites, have advanced astronomy even further.
Aboriginals used astronomy to predict the coming of the seasons and for a path for there ancestors
Some say columns while others say pyramids, but I say that arches have been the greatest contribution to architecture.
Math & astronomy.
what is the most recent candy made
The most recent one is The Matrix Revolutions made in 2003.
He made the petrachian pie. duhhhhhhhh
rapunzel from tangled
four seconds ago.
Pokemon X and Y.
My carport.
Although he made enormously important contributions to physics, his contribution to mathematics was limited. The non-existence of a fixed frame of reference is probably the most significant mathematical contribution - as opposed to contribution to physics.
Type your answer here... the atomic clooks
bill gates
She made a generous contibution to the scholarship fund. What do you feel was George Washington's greatest contribution to the United States? Most families make a small contribution to the church each week.