Pluto’s hazy atmosphere is similar to that of Titan
Pluto is often compared to Neptune’s largest moon, Triton, but its hazy atmosphere is actually more akin to that of Saturn’s largest moon, Titan, which is sometimes viewed as an analog of early Earth.
At the 235th meeting of the American Astronomical Society (AAS) earlier this month in Honolulu, Hawaii, Bonnie Buratti of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, and member of the New Horizons science team, presented a study comparing the atmospheres of Pluto, Triton, and Titan. By modeling these three worlds, each of which have atmospheric hazes, she was able to determine the composition of the hazes, all of which are composed of tiny particles.
Triton, first imaged by Voyager 2 in 1989 and since then studied with ground-based telescopes, was found to have an atmosphere composed of water ice. In contrast, both Pluto and Titan’s atmospheres are composed of organic materials. These organic materials are responsible for the reddish color of Pluto’s atmosphere.
Pluto’s layered hazes were discovered by the New Horizons spacecraft when it flew by the dwarf planet in July 2015.
Buratti described Pluto as “a factory for creating organic molecules. Triton is icy, but Pluto is more like Titan.”
Titan has surface features much like those seen on Earth–dunes, lakes, and seas. These are composed largely of hydrocarbons. Scientists suspect Titan’s surface features are composed of organic molecules that fell from its heavy atmosphere and are now trying to determine whether the same process is occurring on Pluto and whether its haze may be covering lakes and seas like those on Titan.
“The basic thing we’re trying to do is make the connection between the haze and the surface,” Buratti explained.
These findings also raise the possibility of similar phenomena occurring on exoplanets and even on their moons.
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program. Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.