Fragmentary remains of two ancient human relatives, Australopithecus sediba and Homo naledi, were carried aboard a Virgin Galactic flight on Sept. 8. Departing from Spaceport America in New Mexico, the fossils, carried by South African-born billionaire Timothy Nash in a cigar-shaped tube, were rocketed to the edge of space.

"I am horrified that they were granted a permit," Sonia Zakrzewski, a bioarchaeologist at the University of Southampton in the U.K., wrote in an X thread, noting she would use it as an example in her class about unethical approaches. "This is NOT science."