Pluto is its surprisingly complex atmosphere. Although Pluto’s atmosphere
is about 300-600 times less dense
than Mars’ — which is, in turn, about
150 times less dense than Earth’s
— it offers unique insights into the
workings of related planetary atmospheres at Triton and Titan. Whereas
the Earth’s atmosphere contains only
one gas (water vapor), Mars contains two (water vapor and carbon
dioxide), and Pluto’s atmosphere
contains three: nitrogen, carbon
monoxide and methane. Pluto’s
atmosphere has also puffed up over
the years instead of dissipating. Scientists hope to determine why.
New Horizons is outfitted with a
suite of nine different instruments
including two cameras—Ralph and
LORRI. Until recently, the only images
of the dwarf planet were in black
and white. With the release of the
first color images, and now the first
color map, we can see that Mars
may not be the only red planet.
Scientists have known for decades
that Pluto is reddish brown; however,
now we can see it in detail and in
living color. Although Mars and Pluto
have similar hues, they are due to
two very different reasons. Mars gets
its red coloring from iron oxide (aka
rust). Pluto’s reddish coloration is likely
attributed to hydrocarbons (tholins)
formed when cosmic rays and ultraviolet light interact with atmospheric
and surface methane.
As a result of chemical reactions,
the tholins are formed and drop to
ground, forming a reddish gunk that
gives Pluto its color. Tholins are found
in other parts of the Solar System as
well, such as Saturn’s largest moon
Titan and Neptune’s largest moon
Triton—thought to be a twin of Pluto.
New Horizons is expected to give
us unprecedented data on the
whole Pluto system for many months
following the flyby, including data
about its surface, its moons and its
environment, refining our knowledge
of the dwarf planet and its system.
Pluto is not the last stop for New
Horizons. In 2014, the Hubble Space
Telescope identified three possible
KBO’s beyond Pluto for the probe to
flyby. If NASA approves and there’s
funding, the spacecraft will visit one
in 2019.
What is a Dwarf Planet? infographic uploaded to the JPL wwebsite by Jelly.
http://www.jpl.nasa.gov/infographics/infographic.view.php?id=11268
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