"Scientists"

Data returned by the Odyssey Mars Rover suggest that these slope streaks are generally found on the sides of hills and mountains in Martian craters, and that their formation may be caused by frost formed by carbon dioxide at low temperatures

Compared to iron, those rare earth elements in the universe, which are heavier than iron, are even rarer

Harrison Schmitt is the world's twelfth human to set foot on the lunar surface and the only scientist to have landed on the moon. On the 50th anniversary of the first human landing on the moon in June 2019, he warns that many people may be allergic to the dust on the lunar surface