Interesting on the Carson connection!

once you have handed over the money it is yours!.. had the same problem when I started, so still hanging on to it at this stage maybe will use it for something later...but you could try as suggested below by Loes

No harm in trying to contact Carson as Loes suggest

That's...unfortunate...but cannot change. You'd have to register a new one again for the one that you want (I understand cos it is so easy to make a mistake be it typo or something left out ugh)

I made a mistake too and Carson helped me, you can try to contact him and ask if he is willing and able to help you out Domain registration do not end up with the wrong domainname

you can change the name presented to your visitors but not the one in the register.
So you can still use it - most people are looking at the title of the post and the header of the site rather than the name.
remember people searching and finding your articles are looking for those articles rather than looking at the name in any detail - even google got it wrong - it should be googol - and it was named backrub to start with - so further down the line you can transfer your site to another domain name if you want to.
how bad is the typo and will anyone notice?
Phil

As stated below, Sorry .

I'm afraid it isn't possible, once you register a Domain name it is set in stone and can't be altered. You would have to purchase another with the correct spelling.

It's really impossible to change.

Domain names cannot be changed. If you want to have the right spelling, you'll have to buy it again.

Hope that helped!