Changing Planet

Planets can really get around. In the early days of our own solar system, for example, the giant outer planets may have moved toward or away from the Sun by hundreds of millions of miles. And many of the planets seen in other star systems probably have spiraled inward from their birthplaces.

One example is a planet orbiting the star Gliese 1214. The star is smaller and less massive than the Sun, and just one-third of one percent as bright.

The planet is a “mini-Neptune” – bigger and heavier than Earth. It’s so close to the star that it’s extremely hot – about 535 degrees Fahrenheit on the dayside, and 325 degrees on the nightside.

Astronomers studied the planet a couple of years ago with Webb Space Telescope. They found that it’s blanketed by shiny clouds or haze. They reflect half of the starlight that strikes them back into space.

The composition of that layer suggests the planet has gone through some changes during its long lifetime. It might have formed much farther from the star – out beyond the “snow line,” where there was a lot of frozen water and other ices. Over time, it spiraled inward and heated up. The heat changed its atmosphere, producing the hot, shiny brew seen today.

Gliese 1214 is in Ophiuchus, which is high in the south at nightfall. But the star is much too faint to see without a telescope.

Script by Damond Benningfield