Given the short amount of time that New Horizons focused on Pluto, did it capture enough of its surface to create a global map of it?


2 Answers 2


If you mean if New Horizons' data return could produce a global high-resolution map of Pluto's surface, then no, and here's why:

Pluto at New Horizons approach:

Pluto at New Horizons approach

New Horizons Ground Track on Pluto:

New Horizons Ground Track on Pluto

Source of both images is Alan Stern's (New Horizons PI) presentation (PDF) to OPAG Meeting in July 23, 2014.

As you can see, on New Horizons' close approach, Pluto was sunlit on its Southern hemisphere, with its North polar cap in shadow. Solar phase angle on approach was 15°, with New Horizons approaching from Southern hemisphere. Mapping of all the longitudes of the complete Southern hemisphere and up to 15° North was possible due to Pluto's 6.4 Earth days long rotation, and it produced this much of its global map:

The Whale and the Donut:

The Whale and the Donut

This map of Pluto, created from images taken from June 27-July 3, 2015, by the Long Range Reconnaissance Imager (LORRI) on New Horizons, was combined with lower-resolution color data from the spacecraft's Ralph instrument. The center of the map corresponds to the side of Pluto that will be seen close-up during New Horizons' July 14 flyby.

This map gives mission scientists an important tool to decipher the complex and intriguing pattern of bright and dark markings on Pluto's surface. Features from all sides of Pluto can now be seen at a glance and from a consistent perspective, making it much easier to compare their shapes and sizes.

The elongated dark area informally known as "the whale," along the equator on the left side of the map, is one of the darkest regions visible to New Horizons. It measures some 1,860 miles (3,000 kilometers) in length. Directly to the right of the whale’s "snout" is the brightest region visible on the planet, which is roughly 990 miles (1,600 kilometers) across. This may be a region where relatively fresh deposits of frost—perhaps including frozen methane, nitrogen and/or carbon monoxide—form a bright coating.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Since the flyby, Pluto is showing New Horizons its dark side, with only a thin sliver, or a crescent, illuminated by the Sun and showing its atmosphere, and the rest of it is in the shadow. Which is bad for high resolution mapping, but also good for a number of science experiments the probe will do now, including e.g. occultation radio science measurements of Pluto's atmosphere, science requiring long exposure without bright background burn-out, and so on. But it got a good deal of Pluto's surface topography with its instruments, too. For a single flyby, a pretty good return, and expect many more high-resolution images focused on smaller areas, showing a lot more detail than this global map, as it transmits the rest of its flyby data in the following year and a half or so.

You can view the partial global map of Pluto also in Google Earth, if you follow instructions here.

Update: Higher resolution partial global map was just released today:

Global Map of Pluto (with grid):

Global Map of Pluto (with grid)

The science team of NASA’s New Horizons mission has produced an updated global map of the dwarf planet Pluto. The map includes all resolved images of the surface acquired between July 7-14, 2015, at pixel resolutions ranging from 40 kilometers (24 miles) on the Charon-facing hemisphere (left and right sides of the map) to 400 meters (1,250 feet) on the anti-Charon facing hemisphere (map center). Many additional images are expected in fall of 2015 and these will be used to complete the global map.

The New Horizons spacecraft flew past Pluto and its moons on July 14. The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, designed, built, and operates the New Horizons spacecraft, and manages the mission for NASA's Science Mission Directorate. SwRI, based in San Antonio, leads the science team, payload operations and encounter science planning. New Horizons is part of the New Frontiers Program managed by NASA's Marshall Space Flight Center in Huntsville, Alabama.

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Grid here is apparently drawn at every 30°, but isn't labeled. Also obvious is that the map was created with early failsafe New horizons science return using many highly compressed JPeG images, so this will get better over time as complete datasets are transmitted.

Commentary: There's an obvious confusion over North and South hemispheres between released The Whale and the Donut map of Pluto and Alan Stern's presentation. I'm not exactly sure who's in error here, but something got mislabeled. Clarification by APL would be appreciated, but the point stands, we won't get a complete high resolution map of Pluto with this single flyby, despite APL release descriptions being somewhat ambiguous about that. And with all the raw data they're preparing for release on short notice, often requiring a lot of processing, such errors will happen, but should be corrected with higher level releases later on.

  • 2
    $\begingroup$ Fantastic answer, thank you! I also found this site which pulls together all the images into a rotating globe... ianww.com/pluto $\endgroup$
    – Colyn1337
    Commented Jul 28, 2015 at 13:21
  • 1
    $\begingroup$ @Colyn1337 Thanks, and that's a nice page you found there too, it goes straight in my favorites. :) $\endgroup$
    – TildalWave
    Commented Jul 28, 2015 at 13:39
  • $\begingroup$ It is entirely possible that Dr. Stern, who opposes the IAU definition of a planet, is also rebelling against them with respect to the "North" Pole. The IAU has defined the North Pole as the pole Earth's north side of the ecliptic plane since 1982, which flipped the polar labels on retrograde-rotating Pluto, and Stern rejects this move. $\endgroup$ Commented Jan 3, 2021 at 11:44

I'll add a few points to the excellent answer from TidalWave.

  1. We would not be surprised that New Horizons could not map all latitudes of Pluto. Unless we are fortunate enough to hit an equinox, a single flyby is going to find some range of latitudes in polar darkness. In the case of New Horizons flying by Pluto, the missing range was unfortunately large because Pluto has a large axial tilt and New Horizons arrived rather long after the last Pluto equinox. And it would have been worse if the mission had been delayed; see Stern and Grinspoon, Chasing New Horizons, p. 71.

  2. New Horizons did well to get the full 360° range of longitudes at the latitudes that were available. Pluto takes about a week of Earth-time to rotate about its axis, so to get the 360° longitude range the spacecraft would have had to get suitable images for that long -- and therefore, from distances up to several million kilometers. New Horizons managed it with its Long Range Reconnaissance Imager (LORRI), which was "simply" a black-and-white camera coupled with a powerful telescope. LORRI would also play major roles during New Horizons' flyby of Jupiter and (after the Pluto encounter) capturing distant objects in the Kuiper Belt.

  3. Both of the above points applied also to Pluto's major moon Charon (which itself yielded intriguing features to New Horizons). Since Charon is double-locked with Pluto, it had the same visibility constraints as Pluto, and the same long-range requirement for imaging 360° of longitude.


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