Tim Lichtenberg

Planet TOI-561 b orbits its star in less than a day and surprises with its lightness. Infrared observations revealed: the dayside isn't hot enough for bare rock. This means a thick gas coat holds in the heat, rewriting the rules for worlds around bright stars.

After the impact that created the Moon, Earth became a liquid ball. Gravitational 'kneading' heated the planet, prolonging the magma ocean's life from 30 to 500 million years—depending on oxygen levels. Water vapor trapped heat, and weak tides enriched the air with hydrogen. This paints a picture of

Scientists modeled the thermal evolution of sub-Neptunes and found that 98% of these worlds probably harbor a permanent magma ocean under their hydrogen atmosphere. This explains why the most common planet type in the galaxy stays hot inside, even though they were thought to have solidified long ago