According to researchers, the powerful next-generation James Webb Space Telescope revealed a dynamic atmosphere — swirling, gritty clouds — on a planet 40 light-years from Earth in just a few hours of observations.
Designated as VHS 1256 b, the planet orbits not one, but two stars during a 10,000-year period.
During its 22-hour day, the atmosphere is constantly rising, mixing, and flowing, bringing hotter material up and pushing cooler material below. The ensuing brightness variations are so drastic that it is now known to be the most changeable planetary-mass object.
The research team, led by Brittany Miles of the University of Arizona, also detected water, methane, and carbon monoxide with Webb’s data, as well as signs of carbon dioxide. This is the biggest amount of molecules ever discovered all at once on a planet outside our solar system.
“VHS 1256 b is about four times farther from its stars than Pluto is from our Sun, which makes it a great target for Webb,” Miles said. “That means the planet’s light is not mixed with light from its stars.
Temperatures reach a blistering 830 degrees Celsius higher up in its atmosphere, where the silicate clouds are whirling.
Webb identified both bigger and smaller silicate dust grains within those clouds, which are depicted on a spectrum.
“The finer silicate grains in its atmosphere may be more like tiny particles in smoke,” noted co-author Beth Biller of the University of Edinburgh in Scotland. “The larger grains might be more like very hot, very small sand particles.”
VHS 1256 b has low gravity in comparison to more massive brown dwarfs, which allows silicate clouds to form and persist in its atmosphere, where Webb can detect them. Another factor contributing to the planet’s tumultuous sky is its age. It is fairly young in astronomical terms.
It has only been 150 million years since it formed, and it will continue to change and cool over billions of years.
The findings, reported in The Astrophysical Journal Letters, are based on a study of spectra collected by two sensors aboard Webb, the Near-Infrared Spectrograph (NIRSpec) and the Mid-Infrared Instrument (MIDI) (MIRI).
The Webb telescope is a $10 billion international project led by NASA, the European Space Agency, and the Canadian Space Agency. The actual goal of the telescope is to solve mysteries in our solar system, gaze beyond distant worlds orbiting other stars, and investigate the unfathomable architecture and beginnings of our universe and our place in it.