SPANISH scientists have discovered that the dwarf planet Makemake, which orbits the sun, has no atmosphere.
New information about its size, shape and surface properties has been discovered during its rare passage, the researchers reported in Nature.
Makemake – pronounced MAH-kay MAH-kay – orbits farther from the sun than Pluto, which was demoted to the status of dwarf planet and is one of at least four known dwarfs orbiting the sun. In contrast, Pluto has a thin but detectable atmosphere.
“Pluto, Eris and Makemake are among the larger examples of the numerous icy bodies orbiting far away from our sun,” said Jose Ortiz of the Instituto de Astrofisica de Andalucia.
Together with his colleagues, Ortiz has been using the same technique used to probe Eris, an even more distant dwarf planet, a year ago. By studying the change in light of a distant star as Makemake passed directly in front of it, the astronomers said they were able to determine the dwarf planet’s size and surface brightness, results that rule out a global, Pluto-like atmosphere.
“As Makemake passed in front of the star and blocked it out, the star disappeared and reappeared very abruptly, rather than fading and brightening gradually,” Ortiz said. “This means that the little dwarf planet has no significant atmosphere.”