NASA's Hubble telescope has given us some gorgeous images and details of the cosmos. Now, using that telescope, scientists have mapped out the extreme weather of a planet outside our solar system.
This exoplanet, WASP-43b, is about 260 light-years from Earth. Hubble first found it in 2011, but the planet is too far away for photographs. However, Hubble's spectrometers collected data about its variations in light, as its star transited, or passed, in front of it. This allowed scientists to map out the planet's temperatures, as well as determine how much water vapor exists in its atmosphere.
WASP-43b is about the size of Jupiter, although it is more dense, with a chemical composition mostly of hydrogen gas. This means there are no oceans or land masses on its surface, which makes it difficult to map out. However, scientists used Hubble's light readings to figure out its temperature differences and realized that it's a planet of extremes.
Tidal forces keep the planet locked in place so that one side always faces its sun as it orbits around it, much like the Earth's moon. This means that one side of the planet is always in daylight and the other only sees night. Those two sides have huge temperature differences. The side always facing the sun is extremely hot, at 2,800 degrees Fahrenheit, enough to melt steel. However, the nighttime side of the planet is below 1,000 degrees Fahrenheit.
"Our observations are the first of their kind in terms of providing a two-dimensional map on the longitude and altitude of the planet's thermal structure that can be used to constrain atmospheric circulation and dynamical models for hot exoplanets," says Kevin Stevenson of the University of Chicago.
By studying its two sides and viewing its three rotations, scientists estimate that its year, or its orbit around its sun, is only 19 hours. This is because of how close the planet resides to its sun in this system.
This exoplanet is unlike anything in our solar system, so studying it in detail gives us an idea of how planets form and the physics that govern them. As scientists believe water is an important process of how these planets form, the team studied the water vapor in WASP-43b's atmosphere, which had about the same amount of water as our sun.
"These measurements have opened the door for a new kinds of ways to compare the properties of different types of planets," says Jacob Bean of the University of Chicago.
