The exoplanet WASP-43b has water vapor in its atmosphere but it is characterized by extreme weather conditions astronomers do not think it is conducive for hosting life.
Astronomers are hopeful of finding evidence that Mars had once supported life because it used to have an abundance of water. Water alone, however, is not the only key for hosting life. Findings of observations made by scientists using the Hubble Space Telescope of the National Aeronautics and Space Administration (NASA) reveal that although WASP-43b has traces of water vapor in its atmosphere, it is not exactly a place alien life would call home.
Discovered three years ago, the exoplanet WASP-43b is about the size of Jupiter but twice as dense. It is located about 260 light-years away and its distance from the Earth prevents it from being photographed. Astronomers, however, detected it by observing the regular dips in the light of the WASP-43b's orange dwarf parent star, as it orbits in front of it.
In the new study published in the journal Science on Oct. 9, Kevin Stevenson, from the Department of Astronomy and Astrophysics of the University of Chicago, and colleagues, came up with a two-dimensional map of the thermal structure of WASP-43b by mapping the temperatures at different layers of the planet's atmosphere as well as by tracing the amount and distribution of water vapor in it using data from the Hubble Space Telescope.
The Hubble observations reveal that WASP-43b is a planet of extremes. The exoplanet keeps one hemisphere facing its host star, which results in it having different sides for day and night. The temperature in the day side is above 1500 degrees Celsius, which is hot enough to melt an iron. Its pitch-black night side, on the other hand, is characterized by temperatures that could drop to 500 degrees Celsius.
"We construct a map of the planet's atmospheric thermal structure, from which we find large day-night temperature variations at all measured altitudes and a monotonically decreasing temperature with pressure at all longitudes," Stevenson and colleagues reported.
No planet in the solar system has the same extreme weather conditions as those that mark WASP-43b. Scientists hope that characterizing the atmospheric condition of such an odd world can pave way for a better understanding of planetary physics and how planets have formed.
"These measurements have opened the door for a new kinds of ways to compare the properties of different types of planets," said study author Jacob Bean, from the University of Chicago.