"Scientists"

Earthquakes are a common natural phenomenon. On average, millions of earthquakes occur on Earth every year, except that most of them are so mild that they are largely imperceptible to humans.

In this 5.5 million-year-old cave, not only is there no sunlight, but the environment is also very harsh

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