The last option of the poll had me laughing pretty hard...
When Nasa announces something im more excited than a kid on Christmas morning.
Its like finding something you lost years ago times 1000.
My pure guess - traces of H2O
Water discowered on mars long time ago. Polar caps on mars contains a lot of water. It's not a sensation. But finding living microorganisms on mars will be a sensation. That would be exciting. Im waiting for this.
NASA scientists found evidence of perchlorates, (hydrated minerals) which form the streaks on Mars surface.
Before todays announcement, they were just guessing it was water.
It will be incredible when we can actually bring back samples of (
fill in the blank ) back to earth for further study.