What are 2 interesting topics to research about space?

i am doing a picture book about space and i get to choice 3 things to talk about in one of my chapters, i have already chosen greek mytology i need 2 more! help

What are 2 interesting topics to research about space?
the Universal Apocolypse (which is when comets and asteriods go nuts and start to wipe out the planets) i think thats what its called...





and Missions to Mars...Venus ect. building thinigs on mars. like another space station where they build a spaceship on mars and launch from there so they can go farther.








WEIRD RIGHT? I WAS WATCHING THIS THING ON THE NAT. GEOGRAPHIC CHANNEL about it... hope that helps.
Reply:well for me the most interresting fact would be dark matter and dark energy





the second would be pulsars, magnetars and black holes( you can tell them that time and space gets distorted there.....)





well i think you can choos gamma ray bursts also coz they are so obscure
Reply:THE RELATIVITY OF SPACE FLIGHT AND THE RELATIVITY OF FLIGHT IN THE OCEAN. ALSO HOW THE HUBBLE CAN DIFFERENTIATE THE YEARS BETWEEN EARTH AND AN INCOMING OBJECT== HOW ITS MEASURED IN YEARS OR TIME. HAVE A NICE DAY.
Reply:One-was the moon always in earths orbit


Two-Was the asteroid belt originaly created from a planet exsploding sometime in the distance past of our solar systerm.
Reply:How about gamma ray bursts? Or stellar evolution in general? Or the cosmic microwave background?
Reply:Check out nebula's they are beautiful and try supernovas or black holes