We report the results of a study to collect and analyze IPv6 Internet background radiation. This study, the largest of its kind, collects unclaimed traffic on the IPv6 Internet by announcing five large covering prefixes; these cover the majority of allocated IPv6 space on today's Internet. Our analysis characterizes the nature of this traffic across regions, over time, and by the allocation and routing status of the intended destinations, which we show help to identify the causes of this traffic. We compare results to unclaimed traffic in IPv4, and highlight case studies that explain a large fraction of the data or highlight notable properties. We describe how announced covering prefixes differ from traditional network telescopes, and show how this technique can help both network operators and the research community identify additional potential issues and misconfigurations in this critical Internet transition period.