Today’s Google Doodle (Sept 29 2015) was clearly put together in a hurry to commemorate NASA’s announcement of solid evidence for liquid water on Mars:
I actually noticed that last night. So they put it together in a matter of hours.
My Google Doodle is birthday cake. I’ll have to check it out from some other account 
Didn’t we already know that there was water on Mars? I mean, I guess I’m probably wrong, but I thought that was established ages ago.
Well, some of us have known about it since 2009…The Waters of Mars - Wikipedia :p;)
My understanding is that we knew there was ice on Mars (the poles are covered with it), and that it used to be liquid long ago, but this is the first conclusive evidence of current, liquid, flowing water.
For those who missed it, here’s Google’s own doodle blog, which includes both the doodle and the explanation for why they did it.
It’s just so cuuuute!
Edit: and it was probably so quick because they just made a GIF, rather than using HTML5. I had assumed it only worked when you hovered your mouse over it, but apparently, that’s just a delay.