Which one?

[Debi]

AND WHY?​

 

[7Critter]

I choose alien life which includes extra terrestrials, big foot, Mothman, stick man, and every other creature for which we do not have a solid explanation.

 

[Benway]

Dark matter is least interesting as it's like a code for "do this bit later" in physics.
Black holes are really interesting.
If aliens are as 7Christie defines them then it's out of them and the multiverse. Both are relevant to our lives but huge and strange and with all that is known mostly comprising questions with just enough information to go nuts trying to figure things out.

 

[Lynne]

I choose alien life which includes extra terrestrials, big foot, Mothman, stick man, and every other creature for which we do not have a solid explanation.

Im with you Critter on this.

 

[Vibe-Feeler]

Everything to be honest. A lot of aspects regarding space fascinates me.