DNS is a fundamental function of the internet that needs to be accurate and available at all times.
Currently 88.io provides global DNS services from 8 sites in multiple cities:
Amsterdam - 1 site (unicast)
London - 1 site (anycast)
Los Angeles - 1 site (anycast)
Singapore - 1 site (unicast)
Sydney - 3 sites (1 unicast, 2 anycast)
Tokyo - 1 site (anycast)
Besides normal DNS operations, the above sites will resolve important DNS addresses - like yours :) - in case there are problems with the real top level domain servers. They also act as a source for independent monitoring and verification of DNS records.