What happens when I close the lid on my 2009 MBP while time machine is backingup 70gb

What happens when I close the lid on my 2009 MBP while time machine is backing up 70gb of data via wifi to my backup disk which is connected to my airport extreme?

Since time machine runs every hour I never ever pay any attention to it, but now that I think about it, I must be closing the lid on my MBP quite often while it's doing its thing. Normally a backup only takes a couple of minutes but I just restored from a backup so now it's backing up 69GB.

I ask the question because I already closed the lid, and at that point I thought to myself.. OH NO! but I waited 5 minutes and then it went into sleep mode. Fearing that I just corrupted my sparsebundle I opened the lid back up, the computer resumed, and amazingly time machine sort of just kept truckin from right where it left off (at 50gb) and now it's nearly at 66.3 of 69. I hope all it well and it will just finish up just fine.

If thats the case it's just another reason to freaking love my mac! I can't believe that it can go to sleep in the middle of a backup (over wifi none-the-less) and then wakeup and continue like nothing ever happened.

What has been everyones experiences with this? Thanks!

When the lid closes, the machine goes into sleep mode. What happens in a nutshell is that all subsystems turn off and only enough power is used to keep the contents of RAM active. The net effect, as it relates to Time Machine, is that your backup is paused. It will resume once you open the lid, because all suspended processes are simply continued.