“The Sentinel,” Arthur C. Clarke, 1951 – An obelisk of alien origin is discovered on the moon.
Comments: The basis for 2001: A Space Odyssey. Read in The Mirror of Infinity: A Critics’ Anthology of Science Fiction, which provides an introduction by Thomas Clareson. In the short story, the obelisk is a warning to species that might develop nuclear weapons.
Author: Wikipedia: “Sir Arthur Charles Clarke, CBE, FRAS, Sri Lankabhimanya, (16 December 1917 – 19 March 2008) was a British science fiction author, inventor, and futurist, famous for his short stories and novels, among them 2001: A Space Odyssey (1968), and as a host and commentator in the British television series Mysterious World. For many years, Robert A. Heinlein, Isaac Asimov, and Clarke were known as the ‘Big Three’ of science fiction.”