A Harvard astrophysicist and NASA are locked in a public disagreement over a small, shiny object photographed on the Martian surface. The dispute hinges on whether the object is human-made debris or just another wind-carved rock - and the two sides can't even agree on how big it is. The object, captured by NASA's Mars Curiosity rover in 2022, resembles what astrophysicist Avi Loeb described as a metal party hat. NASA says it's a natural formation. Loeb wants the rover sent back to examine it up close.