New Horizons images of Pluto’s largest moon, taken on 11 July 2015, reveal chasms, craters and a dark polar region. Credit: NASA/JHUAPL/SWRI
Images released by NASA as New Horizons prepares for its flyby of Pluto on 14 July show Charon’s surface to feature large chasms and craters.
The most pronounced chasm seen in the images is found in the moon’s southern hemisphere and is thought to be longer and deeper than the Grand Canyon on Earth.
Also revealed is Charon’s most prominent crater, located in the moon’s south pole and measuring roughly 96.5km in diameter.
It is thought that the crater was formed during a collision with a small Kuiper Belt object at some point over the past billion years.
The darkness of the crater’s floor has led scientists to surmise that the impact exposed a different structure of ice than the more reflective forms found on Charon’s surface.
Another theory is that the ice in the crater is the same as the kind found on the surface, but with a larger ice grain size, making it less reflective.
This could be a result of the impact material having melted the ice in the crater floor, causing it to then refreeze in larger grains.
The New Horizons images also reveal an unknown dark region near Charon’s north pole that stretches over a distance of about 320km.
The 14 July flyby is expected to provide further detailed images and enable scientists to learn more about the origins of this mysterious region.
William McKinnon, deputy lead scientist with New Horizons’ Geology and Geophysics investigation team, says:
“This is the first clear evidence of faulting and surface disruption on Charon.
New Horizons has transformed our view of this distant moon from a nearly featureless ball of ice to a world displaying all kinds of geologic activity.”
When New Horizons makes its flyby on 14 July at 7.49am EDT (11.49am UT), the spacecraft will zoom past Pluto at 49,600 kilometers per hour, carrying a suite of seven science instruments that will be gathering data.
This will provide scientists with the most in-depth look at Pluto yet and help us learn more about this largely unknown, icy dwarf planet.