The acceleration of lift-off would not kill something that size, and if a rock is large enough, the heat generated as it is thrownclear will be negligible except at its surface where, if anything, melting may even produce an airtight skin to protect any microbes deeper down from the unpleasant vacuum of space.
There were some principles, he said, that were so important, it was right to make it clear that Plaid "will not accept everything that is thrown at us".