"planet"

Nowadays, Mars is obviously unsuitable for direct human habitation, because the environment of Mars is very different from that of Earth, such as Mars is unusually arid, desolate and without a trace of life. Despite this, scientists are still keen to explore Mars

After the sun evolves into a red giant, the hydrogen in its core is almost completely fused into helium, so the nuclear fusion inside the sun stops, after which the sun loses its internal radiation pressure and continues to collapse, leading to a constant increase in temperature and pressure in its core, while the helium in the central region of the sun is gradually compressed into the condensed state.