Curious about a cached old domain

Question

I am a bit curious about my new domain. I had a domain before, let's say http://example.com/. Before expiration of that domain, I bought a new one with the name http://another-domain.com/. I uploaded all of my content on the second domain, but now when I search in Google about some query related to my http://another-domain.com/ site then I also find my old domain in the results.

Will this give a duplicate content error for my new domain or any other kind of penalty from Google?

Answer 1

For cases as your Google have really helpful facility in their Web Master Tools: 'Change of Address' (Tell Google when you move your site to a new domain). To be able to use this facility I trust you must verify your ownership of the domain (that’s a part of WMT site setup) - so it has to be completed before domain to expire.

Trust Google not care for duplicate content on sites. As example from long time we use area location targeted sites with almost equal content - placed on various domains and sub-domains.