What are the biggest challenges in Astronomy ?

Hi mattithyahu, I expected a lot more from you.

Haha, why is that? It is such a broad topic, it is hard to talk about things we don't know yet because we don't know them... Astronomy is a field that is advancing every day and we are learning new stuff all the time, it is easier to look back to see what we didn't know than to look forward and figure out what we don't.

You are having an experience in astronomy. and i though maybe you could have been more elaborate.