On mass, composition, and temperature Neptune and Uranus are not far from being twins, Neptune is a deep shade of blue befitting a planet named after the god of the sea, while Uranus is paler and slightly greenish. So, why do they look so different?
A new paper undergoing peer review attributes the difference to a layer of initially tiny methane ice particles that sink as they grow, eventually forming a sort of snow that then re-evaporates.
Professor Patrick Irwin of the University of Oxford and colleagues have combined Voyager 2’s data with measurements taken by Hubble and ground-based telescopes to try to make sense of the pairs’ atmospheres. They have presented a model, available to read on arXiv, that might explain the two different shades.
Irwin and co-authors conclude both planets have an atmosphere with a base pressure more than 700 kiloPascals composed of hydrogen sulfide ice and photochemical haze. Yes, as Irwin previously showed, Uranus smells like farts.
Written by Sayoni Mahapatra Chatterji
Early Morning Memories 