The planet absorbs 99% of sunlight

The "hot Jupiter" WASP-104b planet is so dark that it absorbs almost all incoming sunlight.

WASP-104b may be the darkest planet ever discovered. The planet of this hot Jupiter is covered by a mist that absorbs 97 - 99% of the light reaching the surface. The research team at Keele University in New York, England, discovered WASP-104b in arXiv magazine published on April 15, according to Newsweek.

"In every dark planet I can find in studies, the planet is in the top five," said researcher Teo Mocnik. "I think it's in the top three."

WASP-104b is one of the darkest planets ever discovered.(Artwork: NASA).

The WASP-104b and the other two extremely dark planets TrES-2b and HAT-P-7b reflect the same light, so it is difficult to conclude exactly which planet is darkest. The difference in reflected light levels is so small that researchers cannot measure clearly, according to New Scientist.

WASP-104b has the same mass as Jupiter and the orbits near the host star should be classified as "hot Jupiter". Most hot Jupiter planets are dark, reflecting only a maximum of 40% of the light reaching the surface. However, WASP-104b is a special case.

The planet is so close to the host star that it takes only 1.75 days to complete an orbit. The proximity is an important factor in the impressive darkness of WASP-104b, allowing radiation from the star to penetrate the planet's clouds, releasing potassium and sodium to absorb starlight.

The research team focused on WASP-104b for the first time in 2014 in the Wide-Angle Planet Search project and the Kepler space telescope then revealed its ability to absorb light. Astronomers also observed WASP-104b indirectly as it passed ahead and obscured part of the star's light several times. This skimming process reveals important information about WASP-104b, including the amount of light it absorbs.