iMac secret feature or application?

Question

I found this presumably hidden feature by accident; my keyboard fell so I picked it up. When I did, my background looked like it was in space, the Finder window was open and in the middle of the background there was the sun. On the side a new menu bar showed up; one option said "Today" and the other option, I think, said "Tomorrow." It just looked like my background was traveling through space, it was cool; kind of like when you reboot your computer and it gives you that Apple outerspace show.

My question is: how do i open that feature or application and what is it for?

Answer 1

If it looked like this:

you just entered Time Machine. From Apple:

Time Machine is the built-in backup that works with your Mac and an external drive (sold separately) or Time Capsule. Connect the drive, assign it to Time Machine, and start enjoying some peace of mind. Time Machine automatically backs up your entire Mac, including system files, applications, accounts, preferences, music, photos, movies, and documents. But what makes Time Machine different from other backup applications is that it not only keeps a spare copy of every file, it remembers how your system looked on any given day—so you can revisit your Mac as it appeared in the past.

It's not a hidden feature but it does aim to stay unobtrusive and out-of-the-way until you need it.

You can get to Time Machine any time you want by clicking this icon in your menu bar and selecting Enter Time Machine.

If you don't see the Time Machine icon in your menu bar go to System Preferences -> Time Machine and make sure the Show Time Machine status in menu bar option is checked.

Answer 2

What you most likely opened was Time Machine, that is, if your screen looked like this:

This is not at all a hidden feature of Mac OS X, but a very popular one. I don't know what the keyboard shortcut is, but somehow, you activated the application.

Click here to read more about Time Machine.