The first condition for the existence of life is liquid water, and whether a planet is habitable depends on whether the surface temperature can support the existence of liquid water  The surface of ice planets or ice moons was originally covered with ice and snow  Previous studies have believed that as the radiation of stars increases, the ice and snow on its surface will eventually melt to form liquid water, which is suitable for life  However, the latest research proves that as the star's radiation increases, the ice planet or ice moon will directly enter the extremely hot greenhouse escape state, the surface temperature will rise above 100 degrees Celsius, and liquid water cannot exist  Once the ice and snow melt, the sudden reduction in the reflectivity of the planet's surface makes it much more capable of absorbing stellar radiation
In addition, after the ice and snow melt, a large amount of water vapor enters the atmosphere, and the strong greenhouse effect further increases the surface temperature
Icy planets or icy moons aren't actually habitable