The surface of Pluto is becoming better resolved as NASA’s New Horizons spacecraft speeds closer to its July flight through the Pluto system.
A series of new images obtained by the spacecraft’s telescopic Long Range Reconnaissance Imager (LORRI) during May 29-June 2 show Pluto is a complex world with very bright and very dark terrain, and areas of intermediate brightness in between. These images afford the best views ever obtained of the Pluto system.
These images, taken by New Horizons’ Long Range Reconnaissance Imager (LORRI), show four different “faces” of Pluto as it rotates about its axis with a period of 6.4 days. All the images have been rotated to align Pluto’s rotational axis with the vertical direction (up-down) on the figure, as depicted schematically in the upper left.From left to right, the images were taken when Pluto’s central longitude was 17, 63, 130, and 243 degrees, respectively. The date of each image, the distance of the New Horizons spacecraft from Pluto, and the number of days until Pluto closest approach are all indicated in the figure. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
New Horizons scientists used a technique called deconvolution to sharpen the raw, unprocessed pictures that the spacecraft beams back to Earth; the contrast in these latest images has also been stretched to bring out additional details. Deconvolution can occasionally produce artifacts, so the team will be carefully reviewing newer images taken from closer range to determine whether some of the tantalizing details seen in the images released today persist. Pluto’s non-spherical appearance in these images is not real; it results from a combination of the image-processing technique and Pluto’s large variations in surface brightness.
Since April, deconvolved images from New Horizons have allowed the science team to identify a wide variety of broad surface markings across Pluto, including the bright area at one pole that scientists believe is a polar cap.
These images show dramatic variations in Pluto’s surface features as it rotates. When a very large, dark region near Pluto’s equator appears near the limb, it gives Pluto a distinctly, but false, non-spherical appearance. Pluto is known to be almost perfectly spherical from previous data. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
“Even though the latest images were made from more than 30 million miles away, they show an increasingly complex surface with clear evidence of discrete equatorial bright and dark regions—some that may also have variations in brightness,” says New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, Boulder, Colorado. “We can also see that every face of Pluto is different and that Pluto’s northern hemisphere displays substantial dark terrains, though both Pluto’s darkest and its brightest known terrain units are just south of, or on, its equator. Why this is so is an emerging puzzle.”
“We’re squeezing as much information as we can out of these images, and seeing details we’ve never seen before,” said New Horizons Project Scientists Hal Weaver, from the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “We’ve seen evidence of light and dark spots in Hubble Space Telescope images and in previous New Horizons pictures, but these new images indicate an increasingly complex and nuanced surface. Now, we want to start to learn more about what these various surface units might be and what’s causing them. By early July we will have spectroscopic data to help pinpoint that.”
New Horizons is approximately 2.9 billion miles (4.7 billion kilometers) from Earth and just 24 million miles (39 million kilometers) from Pluto. The spacecraft and payload are in good health and operating normally.
These images are displayed at four times the native LORRI image size, and have been processed using a method called deconvolution, which sharpens the original images to enhance features on Pluto. Deconvolution can occasionally introduce “false” details, so the finest details in these pictures will need to be confirmed by images taken from closer range in the next few weeks. All of the images are displayed using the same brightness scale. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
For the first time, images from NASA’s New Horizons spacecraft are revealing bright and dark regions on the surface of faraway Pluto – the primary target of the New Horizons close flyby in mid-July.
The images were captured in early to mid-April from within 70 million miles (113 million kilometers), using the telescopic Long Range Reconnaissance Imager (LORRI) camera on New Horizons. A technique called image deconvolution sharpens the raw, unprocessed images beamed back to Earth. New Horizons scientists interpreted the data to reveal the dwarf planet has broad surface markings – some bright, some dark – including a bright area at one pole that may be a polar cap.
“As we approach the Pluto system we are starting to see intriguing features such as a bright region near Pluto’s visible pole, starting the great scientific adventure to understand this enigmatic celestial object,” says John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “As we get closer, the excitement is building in our quest to unravel the mysteries of Pluto using data from New Horizons.”
Also captured in the images is Pluto’s largest moon, Charon, rotating in its 6.4-day long orbit. The exposure times used to create this image set – a tenth of a second – were too short for the camera to detect Pluto’s four much smaller and fainter moons.
Since it was discovered in 1930, Pluto has remained an enigma. It orbits our sun more than 3 billion miles (about 5 billion kilometers) from Earth, and researchers have struggled to discern any details about its surface. These latest New Horizons images allow the mission science team to detect clear differences in brightness across Pluto’s surface as it rotates.
“After traveling more than nine years through space, it’s stunning to see Pluto, literally a dot of light as seen from Earth, becoming a real place right before our eyes,” said Alan Stern, New Horizons principal investigator at Southwest Research Institute in Boulder, Colorado. “These incredible images are the first in which we can begin to see detail on Pluto, and they are already showing us that Pluto has a complex surface.”
The images the spacecraft returns will dramatically improve as New Horizons speeds closer to its July rendezvous with Pluto,
“We can only imagine what surprises will be revealed when New Horizons passes approximately 7,800 miles (12,500 kilometers) above Pluto’s surface this summer,” said Hal Weaver, the mission’s project scientist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.
APL designed, built, and operates the New Horizons spacecraft, and manages the mission for NASA’s Science Mission Directorate. SwRI 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.
These two “movies” show a series of LORRI images of Pluto and Charon taken at 13 different times spanning 6.5 days, from April 12 to April 18, 2015. During that time, the spacecraft’s distance from Pluto decreased from about 69 million miles (111 million kilometers) to 64 million miles (104 million kilometers).
Pluto and Charon rotate around a center-of-mass (also called the “barycenter”) once every 6.4 Earth days, and these LORRI images capture one complete rotation of the system. The direction of the rotation axis is shown in the figure. In one of these movies, the center of Pluto is kept fixed in the frame, while the other movie is fixed on the center of mass (accounting for the “wobble” in the system as Charon orbits Pluto).
The 3x-magnified view of Pluto highlights the changing brightness across the disk of Pluto as it rotates. Because Pluto is tipped on its side (like Uranus), when observing Pluto from the New Horizons spacecraft, one primarily sees one pole of Pluto, which appears to be brighter than the rest of the disk in all the images. Scientists suggest this brightening in Pluto’s polar region might be caused by a “cap” of highly reflective snow on the surface. The “snow” in this case is likely to be frozen molecular nitrogen ice. New Horizons observations in July will determine definitively whether or not this hypothesis is correct.
In addition to the polar cap, these images reveal changing brightness patterns from place to place as Pluto rotates, presumably caused by large-scale dark and bright patches at different longitudes on Pluto’s surface. In all of these images, a mathematical technique called “deconvolution” is used to improve the resolution of the raw LORRI images, restoring nearly the full resolution allowed by the camera’s optics and detector.
NASA’s New Horizons spacecraft is three months from returning to humanity the first-ever close up images and scientific observations of distant Pluto and its system of large and small moons.
Pluto-Charon in Color: This image of Pluto and its largest moon, Charon, was taken by the Ralph color imager aboard New Horizons on April 9, 2015, from a distance of about 71 million miles (115 million kilometers). It is the first color image ever made of the Pluto system by a spacecraft on approach. (full caption)
“Scientific literature is filled with papers on the characteristics of Pluto and its moons from ground based and Earth orbiting space observations, but we’ve never studied Pluto up close and personal,” said John Grunsfeld, astronaut, and associate administrator of the NASA Science Mission Directorate at the agency’s Headquarters in Washington. “In an unprecedented flyby this July, our knowledge of what the Pluto systems is really like will expand exponentially and I have no doubt there will be exciting discoveries.”
The fastest spacecraft ever launched, New Horizons has traveled a longer time and farther away – more than nine years and three billion miles – than any space mission in history to reach its primary target. Its flyby of Pluto and its system of at least five moons on July 14 will complete the initial reconnaissance of the classical solar system. This mission also opens the door to an entirely new “third” zone of mysterious small planets and planetary building blocks in the Kuiper Belt, a large area with numerous objects beyond Neptune’s orbit.
The flyby caps a five-decade-long era of reconnaissance that began with Venus and Mars in the early 1960s, and continued through first looks at Mercury, Jupiter and Saturn in the 1970s and Uranus and Neptune in the 1980s.
Reaching this third zone of our solar system – beyond the inner, rocky planets and outer gas giants – has been a space science priority for years. In the early 2000s the National Academy of Sciences ranked the exploration of the Kuiper Belt – and particularly Pluto and its largest moon, Charon – as its top priority planetary mission for the coming decade.
New Horizons – a compact, lightweight, powerfully equipped probe packing the most advanced suite of cameras and spectrometers ever sent on a first reconnaissance mission – is NASA’s answer to that call.
“This is pure exploration; we’re going to turn points of light into a planet and a system of moons before your eyes!” said Alan Stern, New Horizons principal investigator from Southwest Research Institute (SwRI) in Boulder, Colorado. “New Horizons is flying to Pluto — the biggest, brightest and most complex of the dwarf planets in the Kuiper Belt. This 21st century encounter is going to be an exploration bonanza unparalleled in anticipation since the storied missions of Voyager in the 1980s.”
Pluto, the largest known body in the Kuiper Belt, offers a nitrogen atmosphere, complex seasons, distinct surface markings, an ice-rock interior that may harbor an ocean, and at least five moons. Among these moons, the largest – Charon – may itself sport an atmosphere or an interior ocean, and possibly even evidence of recent surface activity.
“There’s no doubt, Charon is a rising star in terms of scientific interest, and we can’t wait to reveal it in detail in July,” said Leslie Young, deputy project scientist at SwRI.
Pluto’s smaller moons also are likely to present scientific opportunities. When New Horizons was started in 2001, it was a mission to just Pluto and Charon, before the four smaller moons were discovered.
The spacecraft’s suite of seven science instruments – which includes cameras, spectrometers, and plasma and dust detectors – will map the geology of Pluto and Charon and map their surface compositions and temperatures; examine Pluto’s atmosphere, and search for an atmosphere around Charon; study Pluto’s smaller satellites; and look for rings and additional satellites around Pluto.
Currently, even with New Horizons closer to Pluto than the Earth is to the Sun, the Pluto system resembles little more than bright dots in the distance. But teams operating the spacecraft are using these views to refine their knowledge of Pluto’s location, and skillfully navigate New Horizons toward a precise target point 7,750 miles (12,500 kilometers) from Pluto’s surface. That targeting is critical, since the computer commands that will orient the spacecraft and point its science instruments are based on knowing the exact time and location that New Horizons passes Pluto.
“Our team has worked hard to get to this point, and we know we have just one shot to make this work,” said Alice Bowman, New Horizons mission operations manager at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, which built and operates the spacecraft. “We’ve plotted out each step of the Pluto encounter, practiced it over and over, and we’re excited the ‘real deal’ is finally here.”
The spacecraft’s work doesn’t end with the July flyby. Because it gets one shot at its target, New Horizons is designed to gather as much data as it can, as quickly as it can, taking about 100 times as much data on close approach as it can send home before flying away. And although the spacecraft will send select, high-priority datasets home in the days just before and after close approach, the mission will continue returning the data stored in onboard memory for a full 16 months.
“New Horizons is one of the great explorations of our time,” said New Horizons Project Scientist Hal Weaver at APL. “There’s so much we don’t know, not just about Pluto, but other worlds like it. We’re not rewriting textbooks with this historic mission – we’ll be writing them from scratch.”
APL manages the New Horizons mission for NASA’s Science Mission Directorate in Washington. Alan Stern of SwRI is the principal investigator. SwRI 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.
NASA’s New Horizons spacecraft gets closer each day to Pluto and the fly-by on July 14th. The New Horizons mission, the SETI Institute and the International Astronomical Union (IAU) have opened a public participation program in which you offer an addition to a list of names that will be used for features on Pluto and its moon Charon.
In partnership with NASA’s New Horizons mission and the SETI Institute, the IAU is endorsing a campaign that will allow the public to participate in naming newly discovered features on Pluto and its satellites. It is expected that many new features will be discovered in the upcoming flyby of Pluto and will be available for naming. The public is invited to suggest names within the designated IAU themes for these celestial bodies.
Pluto retains a unique position in the hearts and minds of many. Pluto is a remote and enigmatic world that resides at the edge of the Solar System, in a region known as the Kuiper Belt, where it is one among many similar dwarf planets, although Pluto remains the largest discovered to date.
On 14 July 2015, NASA’s New Horizons probe will fly past Pluto, offering the first close-up look at this small, distant world and its largest satellite, Charon. These denizens of the outer Solar System will, at long last, be transformed from mysterious, hazy bodies into worlds with distinct features.
In celebration of this historic occasion, the IAU is proud to endorse a campaign that will allow members of the public to participate in naming newly imaged and identified features on the surfaces of Pluto and its natural satellites.
You are invited to visit the website ourpluto.seti.org, where you can vote for the names that you think should be used to identify the most prominent features on both Pluto and Charon. You can also suggest additional names. These must be associated with a set of accepted themes set out by the IAU’s Working Group for Planetary System Nomenclature (WGPSN) related to mythology and the literature and history of exploration:
Names for the Underworld from the world’s mythologies.
Gods, goddesses, and dwarfs associated with the Underworld.
Heroes and other explorers of the Underworld.
Writers associated with Pluto and the Kuiper Belt.
Scientists and engineers associated with Pluto and the Kuiper Belt.
Destinations and milestones of fictional space and other exploration.
Fictional and mythological vessels of space and other exploration.
Fictional and mythological voyagers, travellers and explorers.
Deities of the night.
Dogs from literature, mythology and history.
Legendary serpents and dragons.
Please note, however, that votes for other themes will not be taken into account, incl. the following, since these themes have already been used on Mercury, Venus and Mars:
Space missions and spacecraft names.
Authors, artists, directors and producers of the fiction of exploration.
Explorers of the Earth, air and seas.
The campaign ends on 7 April 2015, after which the New Horizons team will sort through the names and submit their recommendations to the IAU. The IAU will have the final decision on how the names are used.