Dwarf planet Makemake is about two thirds of the size of Pluto, and travels around the Sun in a distant path that lies beyond that of Pluto but closer to the Sun than Eris, the most massive known dwarf planet in the Solar System. Previous observations of chilly Makemake have shown it to be similar to its fellow dwarf planets, leading some astronomers to expect its atmosphere, if present, to be similar to that of Pluto. However, the new study now shows that, like Eris, Makemake is not surrounded by a significant atmosphere.
The team, led by Jose Luis Ortiz (Instituto de Astrofisica de Andalucia, CSIC, Spain), combined multiple observations using three telescopes at ESO's La Silla and Paranal observing sites in Chile -- the Very Large Telescope (VLT), New Technology Telescope (NTT), and TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) -- with data from other small telescopes in South America, to look at Makemake as it passed in front of a distant 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 Jose Luis Ortiz. "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's lack of moons and its great distance from us make it difficult to study, and what little we do know about the body is only approximate. The team's new observations add much more detail to our view of Makemake -- determining its size more accurately, putting constraints on a possible atmosphere and estimating the dwarf planet's density for the first time. They have also allowed the astronomers to measure how much of the Sun's light Makemake's surface reflects -- its albedo. Makemake's albedo, at about 0.77, is comparable to that of dirty snow, higher than that of Pluto, but lower than that of Eris.
It was only possible to observe Makemake in such detail because it passed in front of a star -- an event known as a stellar occultation. These rare opportunities are allowing astronomers for the first time to find out a great deal about the sometimes tenuous and delicate atmospheres around these distant, but important, members of the Solar System, and providing very accurate information about their other properties.
Occultations are particularly uncommon in the case of Makemake, because it moves in an area of the sky with relatively few stars. Accurately predicting and detecting these rare events is extremely difficult and the successful observation by a coordinated observing team, scattered at many sites across South America, ranks as a major achievement.
"Pluto, Eris and Makemake are among the larger examples of the numerous icy bodies orbiting far away from our Sun," says Jose Luis Ortiz. "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."
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
A study of three mice that spent 91 days on the International Space Station finds abnormalities in their skin.
Both NASA and private firms want to drag resource-rich asteroids closer to home to mine them, but that could stir up dust that could collide with satellites
Amid uncertainty over future Russian space station missions, NASA orders first crew flight from Boeing and awaits information
There's a lot of messy housekeeping when you're in orbit—and a lot of exciting work too
It's traveling at 98% the speed of light, from a galaxy 260 million light years away
WASHINGTON (Reuters) - The U.S. Air Force on Tuesday said it has certified privately held SpaceX to launch U.S. military and spy satellites, ending a monopoly held by United Launch Alliance, a joint venture of Lockheed Martin Corp and Boeing Co, since its creation in 2006.
Instrument selection has taken place for a robotic mission to study the habitability and vast sub-surface ocean of Europa
UAE Space Agency aims to become an industry leader with ambitious new plans, including a mission to Mars
United Launch Alliance, a 50-50 joint venture of Lockheed Martin Corp and Boeing Co, on Thursday said it would go out of business unless it won commercial and civil satellite launch orders to offset an expected slump in U.S. military and spy launches.
Jessica Banks was an astrophysicist at NASA; then she started RockPaperRobot and innovated the design of furniture and homes by incorporating advanced physics.