The dwarf planet Makemake was previously thought to be similar to other dwarf planets such as Pluto, but a new study suggests that it has one very significant difference: it lacks a potent atmosphere.
Makemake is approximately two-thirds the size of Pluto (which, by the way, was relegated to 'dwarf planet' status six years ago) and sports a chilly exterior due to its distance from our sun. Makemake's lack of moons and distant location mean this is a tough planet for scientists to study - that is, until it passes in front of a star.
"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. This means that the little dwarf planet has no significant atmosphere," says team leader Jose Luis Ortiz from the Instituto de Astrofisica de Andalucia in Spain.
The observation allowed scientists to calculate the dwarf planet's density for the first time.
"It was thought that Makemake had a good chance of having developed an atmosphere -- that it has no sign of one at all shows just how much we have yet to learn about these mysterious bodies. Finding out about Makemake's properties for the first time is a big step forward in our study of the select club of icy dwarf planets."
Makemake is one of three large dwarf planets that orbit our sun outside our eight-planet solar system. Pluto is the closest, and Eris, the largest dwarf planet in our solar system, is further out than Makemake. Unlike Pluto and Eris, however, it seems that Makemake lacks a significant atmosphere. By better understanding Makemake, scientists hope to build better profiles of dwarf planets throughout space.
"Pluto, Eris and Makemake are among the larger examples of the numerous icy bodies orbiting far away from our Sun," Ortiz said. "Our new observations have greatly improved our knowledge of one of the biggest, Makemake -- we will be able to use this information as we explore the intriguing objects in this region of space further."
Read the study published in the journal Nature.