Science

Pluto's cold sister planet has no atmosphere

Astronomers say Pluto's icy more distant sister seems even more alien than thought because it doesn't have an atmosphere.
This artist's impression shows the surface of the distant Makemake. The dwarf planet is about two-thirds 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. Astronomers say Pluto's icy, more distant sister seems even more alien because they found it doesn't have an atmosphere. European Southern Observatory/Nature/AP Photo

Astronomers say Pluto's icy more distant sister seems even more alien than thought because it doesn't have an atmosphere.

Scientists gained that bit of new knowledge about the dwarf planet Makemake (proounced MAH'-kay MAH'-kay) by measuring light from data gathered by several large telescopes.

Researchers report in the journal Nature that the small planet may simply have some pockets of atmosphere from methane ice turning into gas.  

Makemake is one of four dwarf planets in our solar system beyond Neptune. It is so far from the sun its temperature is about –240 degrees Celsius. Scientists compare it to getting warmth from a 100-watt light bulb 10 metres away. It was discovered in 2005.

Corrections

  • An earlier version of this article gave the temperature on dwarf planet Makemake in Fahrenheit (–400) but did not specify the units.
    Nov 21, 2012 10:00 AM ET

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