The last image of Pluto’s opposition hemisphere

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Pluto's opposition hemisphere

Cool image time! The New Horizons team has released the best image they are ever going to get of the hemisphere that will be facing away from the spacecraft when it does its fly-by on July 14.

The spots appear on the side of Pluto that always faces its largest moon, Charon—the 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 Pluto’s far side for decades to come.”

The spots are connected to a dark belt that circles Pluto’s equatorial region. What continues to pique the interest of scientists is their similar size and even spacing. “It’s weird that they’re spaced so regularly,” says New Horizons program scientist Curt Niebur at NASA Headquarters in Washington. Jeff Moore of NASA’s Ames Research Center, Mountain View, California, is equally intrigued. “We can’t tell whether they’re plateaus or plains, or whether they’re brightness variations on a completely smooth surface.”

No one will likely have the answers to these questions for a long time, as it might take as long as a half century before before anyone can get another spacecraft there.


  • mpthompson

    I would be willing to bet that enough details will emerge from examining the other side of Pluto that reasonable guesses could be made regarding the features poorly imaged on the “far” side. Still, I’m bit surprised that much sharper images couldn’t be obtained from the current distance of the probe.

    Too bad that Pluto couldn’t be orbited. I assume that the New Horizons is travelling so fast that the delta-v for orbital insertion was just too much to make an orbital capture by Pluto realistic without blowing out the cost of the mission.

    An alternative would have been a one or more smaller cube-sat size probes that could have detached and captured imagery of other hemispheres as they zoomed past with the data relayed to New Horizons over the coming weeks. Still would have added a lot of cost and risk to the project though.

    I guess I should be happy with what New Horizons is (will be) providing. Never thought that Pluto would be imaged up close in my lifetime. I was born in 1965 when Mariner 4 provided the first fuzzy images of the planet Mars on a flyby. Those images didn’t look much different from these early fuzzy images of Pluto. Planetary science has come a LONG way in the last 50 years.

    Keeping my fingers crossed things continue to go well for the mission.

  • Nick P

    Don’t know if anyone else is monitoring NASA’s website but pictures are coming in more frequently now. The last one from 1 million miles. I’m also quite surprised at the low resolution. I could get better detail of the moon at 1 million miles with my cheap guide scope. Still, it’s much much better than nothing.

  • Maurice

    From the looks of it, it appears that
    a. the atmosphere on Pluto has frozen onto the surface from the north pole down. The black band could be the original surface, or the surface composition reacted to be non-reflective
    b. the southern polar region has something going for it the northern half doesn’t
    c. or we wait 2 days and find out :-)

    At this point, it’s been 85 years since we found Pluto, 2 days of waiting is nothing :)

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