Science
Related: About this forumNew Horizons’ Last Portrait of Pluto’s Puzzling Spots (NASA)
Three billion miles from Earth and just two and a half million miles from Pluto, NASAs New Horizons spacecraft has taken its best image of four dark spots that continue to captivate.
The spots appear on the side of Pluto that always faces its largest moon, Charonthe face that will be invisible to New Horizons when the spacecraft makes its close flyby the morning of July 14. New Horizons principal investigator Alan Stern of the Southwest Research Institute, Boulder, Colorado, describes this image as the last, best look that anyone will have of Plutos far side for decades to come.
The spots are connected to a dark belt that circles Plutos equatorial region. What continues to pique the interest of scientists is their similar size and even spacing. Its weird that theyre spaced so regularly, says New Horizons program scientist Curt Niebur at NASA Headquarters in Washington. Jeff Moore of NASAs Ames Research Center, Mountain View, California, is equally intrigued. We cant tell whether theyre plateaus or plains, or whether theyre brightness variations on a completely smooth surface.
The large dark areas are now estimated to be 300 miles (480 kilometers) across, an area roughly the size of the state of Missouri. In comparison with earlier images, we now see that the dark areas are more complex than they initially appeared, while the boundaries between the dark and bright terrains are irregular and sharply defined.
In addition to solving the mystery of the spots, the New Horizons Geology, Geophysics and Imaging team is interested in identifying other surface features such as impact craters, formed when smaller objects struck the dwarf planet. Moore notes, When we combine images like this of the far side with composition and color data the spacecraft has already acquired but not yet sent to Earth, we expect to be able to read the history of this face of Pluto.
When New Horizons makes its closest approach to Pluto in just three days, it will focus on the opposing or encounter hemisphere of the dwarf planet. On the morning of July 14, New Horizons will pass about 7,800 miles (12,500 kilometers) from the face with a large heart-shaped feature thats captured the imagination of people around the world.
Image caption: New Horizons' last look at Pluto's Charon-facing hemisphere reveals intriguing geologic details that are of keen interest to mission scientists. This image, taken early the morning of July 11, 2015, shows newly-resolved linear features above the equatorial region that intersect, suggestive of polygonal shapes. This image was captured when the spacecraft was 2.5 million miles (4 million kilometers) from Pluto.
Image credit: NASA/JHUAPL/SWRI
At 7:49 AM EDT on Tuesday, July 14 New Horizons will zip past Pluto at 30,800 miles per hour (49,600 kilometers per hour), with a suite of seven science instruments busily gathering data. The mission will complete the initial reconnaissance of the solar system with the first-ever look at the icy dwarf planet.
Follow the path of the spacecraft in coming days in real time with a visualization of the actual trajectory data, using NASAs online Eyes on Pluto.
Stay in touch with the New Horizons mission with #PlutoFlyby and on Facebook at: https://www.facebook.com/new.horizons1
Last Updated: July 11, 2015
Editor: Tricia Talbert
Tags: Dwarf Planets, New Horizons, Pluto, Solar System
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(Press release at http://www.nasa.gov/image-feature/new-horizons-last-portrait-of-pluto-s-puzzling-spots , so no four-para limit)
Warpy
(111,277 posts)especially the one to the right of center.
The next few weeks as data are analyzed are going to be very exciting.
Warren DeMontague
(80,708 posts)whether that's liquid nitrogen volcanoes like on Triton, or methane melting and re-freezing depending on the "season". Something is going on down there which seems to have gotten rid of the craters.
Warpy
(111,277 posts)and was warmer than expected. While it could be liquid helium, anything else would require a slightly warmer planet.
Every single probe we've sent out has provided a few shockers. I doubt this one will be different.
Warren DeMontague
(80,708 posts)Judging from what we've seen so far, my layman's opinion is it sure looks like SOME form of liquid is doing something down there.
Warpy
(111,277 posts)It's dim, but it looks like they're partially filled with some sort of liquid, too.
Even if it's solidified molten rock, it will tell us that Pluto has been geologically active in some way and fairly recently.