One of the exoplanets that Webb will study is called 55 Cancri e; it has some Earth-like qualities, but it is very hot. This is a type of planet called super-Earth, which means it is potentially as rocky as Earth, but it is larger than our planet, although it is not as big as an ice giant like Neptune (via NASA). ). With an orbit of just 1.5 million miles from its star, which is 4% of the distance between Mercury and the Sun, it lasts only 18 hours a year. This means that the planet is close and personal to its star, so it is extremely hot and is bombarded by radiation.
The planet is so hot on the surface, in fact, that the temperatures are high enough to melt the rock. This leads researchers to think that the planet must be covered in oceans of lava as the rocks melt in the heat of the star. In addition, planets orbiting so close to 55 Cancer are thought to be blocked by the tide, which means that one side of the planet is always looking at its star. Normally, this side, called the day side, will heat up much more than the space facing the side, called the night side. And strange weather events can occur when there is a large temperature difference between these two halves of the planet.
On the tide-blocked exoplanet WASP-121b, temperature differences mean there could be metal clouds and rain of liquid gems (via MPI). At 55 Cancri e, however, there is something strange about it, as readings with the Spitzer Space Telescope showed that the hottest part of the planet does not appear to align with the star-facing part.