Nasa probe's early Pluto data shows dwarf planet larger than anticipated
Source: The Guardian
A Nasa spacecraft that will hurtle past Pluto tomorrow at more than 45,000 kilometres per hour has revealed the dwarf planet to be larger than scientists thought.
Fresh measurements from New Horizons, the first spacecraft to reach Pluto on the outer edge of the solar system, show that it is 2,370 kilometres across, roughly two-thirds the size of Earth’s moon.
Alan Stern, the lead scientist on the $700m (£450m) mission, said the increased dimensions meant Pluto must hold more ice and less rock beneath its surface than researchers had expected. Pluto has been hard to measure with any accuracy from Earth because it is so far away, and its atmosphere creates mirages that can fool ground-based telescopes.
Other instruments onboard New Horizons confirmed that Pluto’s north pole bears an icy cap. The latest measurements beamed to Earth from the probe picked up chemical signatures of methane and nitrogen ice in the polar cap.
Read more: http://www.theguardian.com/science/2015/jul/13/nasa-probes-early-pluto-data-shows-dwarf-planet-larger-than-anticipated
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Mystery abounds...
New Horizons’ newest images reveal Pluto’s largest moon Charon to be a world of chasms and craters. The most pronounced chasm, which lies in the southern hemisphere, is longer and miles deeper than Earth’s Grand Canyon, according to William McKinnon, deputy lead scientist with New Horizon’s Geology and Geophysics investigation team.
“This is the first clear evidence of faulting and surface disruption on Charon,” says McKinnon, who is based at the Washington University in St. Louis. “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.”
https://www.nasa.gov/feature/charon-s-chasms-and-craters
Chasms, craters, and a dark north polar region are revealed in this image of Pluto’s largest moon Charon taken by New Horizons on July 11, 2015. Credits: NASA/JHUAPL/SWRI
