Uh … yeah. All. The. Time. We even gave it a name: 1AU.
No. 1AU is a unit of measure. The actual length of an official unit of measure is somewhat arbitrary as you sort of implied. Someone makes that decision. If it were a consensus, it would vary over the years. The actual distance to between the Earth and the Sun is called a “measurement”. And that is why no consensus is needed…as is the case with all science.
“Historically, the claim of consensus has been the first refuge of scoundrels; it is a way to avoid debate by claiming that the matter is already settled. Whenever you hear the consensus of scientists agrees on something or other, reach for your wallet, because you’re being had. Let’s be clear: the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world. In science consensus is irrelevant. What is relevant is reproducible results. The greatest scientists in history are great precisely because they broke with the consensus.” ~ Michael Crichton
