Pluto Archives

July 16, 2015February 6, 2017 by Matt Williams

New Horizons Mission to Pluto

Artist's impression of the New Horizons spacecraft in orbit around Pluto (Charon is seen in the background). Credit: NASA/JPL

Humans have been sending spacecraft to other planets, as well as asteroid and comets, for decades. But rarely have any of these ventured into the outer reaches of our Solar System. In fact, the last time a probe reached beyond the orbit of Saturn to explore the worlds of Neptune, Uranus, Pluto and beyond was with the Voyager 2 mission, which concluded back in 1989.

But with the New Horizons mission, humanity is once again peering into the outer Solar System and learning much about its planets, dwarf planets, planetoids, moons and assorted objects. And as of July 14th, 2015, it made its historic rendezvous with Pluto, a world that has continued to surprise and mystify astronomers since it was first discovered.

Background:

In 1980, after Voyager 1‘s flyby of Saturn, NASA scientists began to consider the possibility of using Saturn to slingshot the probe towards Pluto to conduct a flyby by 1986. This would not be the case, as NASA decided instead to conduct a flyby of Saturn’s moon of Titan – which they considered to be a more scientific objective – thus making a slingshot towards Pluto impossible.

Because no mission to Pluto was planned by any space agency at the time, it would be years before any missions to Pluto could be contemplated. However, after Voyager 2′s flyby of Neptune and Triton in 1989, scientists once again began contemplating a mission that would take a spacecraft to Pluto for the sake of studying the Kuiper Belt and Kuiper Belt Objects (KBOs).

Voyager 2. Credit: NASA — *Artist’s impression of the Voyager spacecraft in flight. Credit: NASA/JPL*

In May 1989, a group of scientists, including Alan Stern and Fran Bagenal, formed an alliance called the “Pluto Underground”. Committed to the idea of mounting an exploratory mission to Pluto and the Kuiper Belt, this group began lobbying NASA and the US government to make it this plan a reality. Combined with pressure from the scientific community at large, NASA began looking into mission concepts by 1990.

During the course of the late 1990s, a number of Trans-Neptunian Objects (TNOs) were discovered, confirming the existence of the Kuiper Belt and spurring interest in a mission to the region. This led NASA to instruct the JPL to re-purpose the mission as a Pluto and KBO flyby. However, the mission was scrapped by 2000, owing to budget constraints.

Backlash over the cancellation led NASA’s Science Mission Directorate to create the New Frontiers program which began accepting mission proposals. Stamatios “Tom” Krimigis, head of the Applied Physics Laboratory’s (APL) space division, came together with Alan Stern to form the New Horizons team. Their proposal was selected from a number of submissions, and officially selected for funding by the New Frontiers program in Nov. 2001.

Despite additional squabbles over funding with the Bush administration, renewed pressure from the scientific community allowed the New Horizons team managed to secure their funding by the summer of 2002. With a commitment of $650 million for the next fourteen years, Stern’s team was finally able to start building the spacecraft and its instruments.

Engineers working on the New Horizons spacecraft's Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument. Credit: NASA — *Engineers working on the New Horizons spacecraft’s Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument. Credit: NASA*

Mission Profile:

New Horizons was planned as a voyage to the only unexplored planet in the Solar System, and was originally slated for launch in January 2006 and arrival at Pluto in 2015. Alan Stern was selected as the mission’s principal investigator, and construction of the spacecraft was handled primarily by the Southwest Research Institute (SwRI) and the Johns Hopkins Applied Physics Laboratory, with various contractor facilities involved in the navigation of the spacecraft.

Meanwhile, the US Naval Observatory (USNO) Flagstaff Station – in conjunction with NASA and JPL – was responsible for performing navigational position data and related celestial frames. Coincidentally, the UNSO Flagstaff station was where the photographic plates that led to the discovery of Pluto’s moon Charon came from.

In addition to its compliment of scientific instruments (listed below), there are several cultural artifacts traveling aboard the spacecraft. These include a collection of 434,738 names stored on a compact disc, a piece of Scaled Composites’s SpaceShipOne, and a flag of the USA, along with other mementos. In addition, about 30 g (1 oz) of Clyde Tombaugh’s ashes are aboard the spacecraft, to commemorate his discovery of Pluto in 1930.

*The New Horizons spacecraft takes off on Jan. 19, 2006 from the Kennedy Space Center for its planned close encounter with Pluto. Credit: NIKON/Scott Andrews/NASA*

Instrumentation:

The New Horizons science payload consists of seven instruments. They are (in alphabetically order):

Alice: An ultraviolet imaging spectrometer responsible for analyzing composition and structure of Pluto’s atmosphere and looks for atmospheres around Charon and Kuiper Belt Objects (KBOs).
LORRI: (Long Range Reconnaissance Imager) a telescopic camera that obtains encounter data at long distances, maps Pluto’s farside and provides high resolution geologic data.
PEPSSI: (Pluto Energetic Particle Spectrometer Science Investigation) an energetic particle spectrometer which measures the composition and density of plasma (ions) escaping from Pluto’s atmosphere.
Ralph: A visible and infrared imager/spectrometer that provides color, composition and thermal maps.
REX: (Radio Science EXperiment) a device that measures atmospheric composition and temperature; passive radiometer.
SDC: (Student Dust Counter) built and operated by students, this instrument measures the space dust peppering New Horizons during its voyage across the solar system.
SWAP: (Solar Wind Around Pluto) a solar wind and plasma spectrometer that measures atmospheric “escape rate” and observes Pluto’s interaction with solar wind.

Instruments New Horizons will use to characterize Pluto are REX (atmospheric composition and temperature; PEPSSI (composition of plasma escaping Pluto's atmosphere); SWAP (solar wind); LORRI (close up camera for mapping, geological data); Star Dust Counter (student experiment measuring space dust during the voyage); Ralph (visible and IR imager/spectrometer for surface composition and thermal maps and Alice (composition of atmosphere and search for atmosphere around Charon). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute — *The instruments New Horizons will use to characterize Pluto. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute*

Launch:

Due to a series of weather-related delays, the New Horizons mission launched on January 19th, 2006, two days later than originally scheduled. The spacecraft took off from Cape Canaveral Air Force Station, Florida, at 15:00 EST (19:00 UTC) atop an Atlas V 551 rocket. This was the first launch of this particular rocket configuration, which has a third stage added to increase the heliocentric (escape) speed.

The spacecraft left Earth faster than any spacecraft to date, achieving a launch velocity of 16.5 km/s. It took only nine hours to reach the Moon’s orbit, passing lunar orbit before midnight (EST) on the same day it was launched. It has not, however, broken Voyager 1‘s record – which is currently traveling at 17.145 km/s (61,720 km/h, 38,350 mph) relative to the Sun – for being the fastest spacecraft to leave the Solar System.

Inner Solar System:

Between January and March, 2006, mission controllers guided the probe through a series of trajectory-correction maneuvers (TCMs). During the week of February 20th, 2006, controllers conducted in-flight tests on three of the major on board science instruments. On April 7th, the spacecraft passed the orbit of Mars, moving at roughly 21 km/s (76,000 km/h; 47,000 mph) away from the Sun.

At this point in its journey, the spacecraft had reached a distance of 243 million kilometers from the Sun, and approximately 93.4 million km from Earth. On June 13th, 2006, the New Horizons spacecraft passed the tiny asteroid 132524 APL at a distance of 101,867 km (63,297 mi) when it was closest.

Using the Ralph instrument, New Horizons was able to capture images of the asteroid, estimating to be 2.5 km (1.6 mi) in diameter. The spacecraft also successfully tracked the asteroid from June 10th-12th, 2006, allowing the mission team to test the spacecraft’s ability to track rapidly moving objects.

First images of Pluto in September 2006. Credit: NASA — *First images of Pluto taken by New Horizons in September 2006. Credit: NASA*

From September 21st-24th, New Horizons managed to capture its first images of Pluto while testing the LORRI instruments. These images, which were taken from a distance of approximately 4,200,000,000 km (2.6×10⁹ mi) or 28.07 AU and released on November 28th, confirmed the spacecraft’s ability to track distant targets.

Outer Solar System:

On September 4th, 2006, New Horizons took its first pictures of Jupiter at a distance of 291 million kilometers (181 million miles). The following January, it conducted more detailed surveys of the system, capturing an infrared image of the moon Callisto, and several black and white images of Jupiter itself.

By February 28th, 2007, at 23:17 EST (03:17, UTC) New Horizons made its closest approach to Europa, at a distance of 2,964,860 km (1,842,278 mi). At 01:53:40 EST (05:43:40 UTC), the spacecraft made its flyby of Jupiter, at a distance of 2.3 million km (1.4 million mi) and received a gravity assist.

The Jupiter flyby increased New Horizons‘ speed by 4 km/s (14,000 km/h; 9,000 mph), accelerating the probe to a velocity of 23 km/s (83,000 km/h; 51,000 mph) relative to the Sun and shortening its voyage to Pluto by three years.

The encounter with Jupiter not only provided NASA with the opportunity to photograph the planet using the latest equipment, it also served as a dress rehearsal for the spacecraft’s encounter with Pluto. As well as testing the imaging instruments, it also allowed the mission team to test the communications link and the spacecraft’s memory buffer.

*Black and white image of Jupiter viewed by LORRI in January 2007. Credit: NASA/John Hopkins University Applied Physics Laboratory/Southwest Research Institute*

One of the main goals during the Jupiter encounter was observing its atmospheric conditions and analyzing the structure and composition of its clouds. Heat-induced lightning strikes in the polar regions and evidence of violent storm activity were both observed. In addition, the Little Red Spot, was imaged from up close for the first time. The New Horizons spacecraft also took detailed images of Jupiter’s faint ring system. Traveling through Jupiter’s magnetosphere, the spacecraft also managed to collect valuable particle readings.

The flyby of the Jovian systems also gave scientists the opportunity to examine the structure and motion of Io’s famous lava plumes. New Horizons measured the plumes coming from the Tvashtar volcano, which reached an altitude of up to 330 km from the surface, while infrared signatures confirmed the presence of 36 more volcanoes on the moon.

Callisto’s surface was also analyzed with LEISA, revealing how lighting and viewing conditions affect infrared spectrum readings of its surface water ice. Data gathered on minor moons such as Amalthea also allowed NASA scientists to refine their orbit solutions.

After passing Jupiter, New Horizons spent most of its journey towards Pluto in hibernation mode. During this time, New Horizons crossed the orbit of Saturn (June 8, 2008) and Uranus on (March 18, 2011). In June 2014, the spacecraft emerged from hibernation and the team began conducting instrument calibrations and a course correction,. By August 24th, 2014, it crossed Neptune’s orbit on its way to Pluto.

Capturing Callisto — *New Horizons Long Range Reconnaissance Imager (LORRI) captured these two images of Jupiter’s outermost large moon, Callisto, during its flyby in February 2007. Credit: NASA/JPL*

Rendezvous with Pluto:

Distant-encounter operations at Pluto began on January 4th, 2015. Between January 25th to 31st, the approaching probe took several images of Pluto, which were released by NASA on February 12th. These photos, which were taken at a distance of more than 203,000,000 km (126,000,000 mi) showed Pluto and its largest moon, Charon.

Investigators compiled a series of images of the moons Nix and Hydra taken from January 27th through February 8th, 2015, beginning at a range of 201,000,000 km (125,000,000 mi), while Kerberos and Styx were captured by photos taken on April 25.

On July 4th, 2015, NASA lost contact with New Horizons after it experienced a software anomaly and went into safe mode. On the following day, NASA announced that they had determined it to be the result of a timing flaw in a command sequence. By July 6th, the glitch had been fixed and the probe had exited safe mode and began making its approach.

The New Horizons spacecraft made its closest approach to Pluto at 07:49:57 EDT (11:49:57 UTC) on July 14th, 2015, and then Charon at 08:03:50 EDT (12:03:50 UTC). Telemetries confirming a successful flyby and a healthy spacecraft reached Earth on 20:52:37 EDT (00:52:37 UTC).

During the flyby, the probe captured the clearest pictures of Pluto to date, and full analyses of the data obtained is expected to take years to process. The spacecraft is currently traveling at a speed of 14.52 km/s (9.02 mi/s) relative to the Sun and at 13.77 km/s (8.56 mi/s) relative to Pluto.

*Full trajectory of New Horizons space probe (sideview). Credit: pluto.jhuapl.edu*

Future Objectives:

With its flyby of Pluto now complete, the New Horizons probe is now on its way towards the Kuiper Belt. The goal here is to study one or two other Kuiper Belt Objects, provided suitable KBOs are close to New Horizons‘ flight path.

Three objects have since been selected as potential targets, which were provisionally designated PT1 (“potential target 1”), PT2 and PT3 by the New Horizons team. These have since been re-designated as 2014 MU69 (PT1), 2014 OS393 (PT2), and 2014 PN70 (PT3).

All of these objects have an estimated diameter of 30–55 km, are too small to be seen by ground telescopes, and are 43–44 AU from the Sun, which would put the encounters in the 2018–2019 period. All are members of the “cold” (low-inclination, low-eccentricity) classical Kuiper Belt, and thus very different from Pluto.

Even though it was launched far faster than any outward probe before it, New Horizons will never overtake either Voyager 1 or Voyager 2 as the most distant human-made object from Earth. But then again, it doesn’t need to, given that what it was sent out to study all lies closer to home.

What’s more, the probe has provided astronomers with extensive and updated data on many of planets and moons in our Solar System – not the least of which are the Jovian and Plutonian systems. And last, but certainly not least, New Horizons is the first spacecraft to have it made it out to such a distance since the Voyager program.

And so we say so long and good luck to New Horizons, not to mention thanks for providing us with the best images of Pluto anyone has ever seen! We can only hope she fares well as she makes its way into the Kuiper Belt and advances our knowledge of the outer Solar System even farther.

We have many interesting articles about the New Horizons spacecraft and Pluto here on Universe Today. For example, here are some Interesting Facts About Pluto, How Long Does it Take to Get to Pluto, Why Pluto is No Longer Considered a Planet, and Is There Life on Pluto?

For more information on the Kuiper Belt, check out What is The Kuiper Belt? and NASA’s Solar System Exploration entry on the Kuiper Belt and Oort Cloud.

Astronomy Cast also has some fascinating episodes on Pluto, including On Pluto’s Doorstep – Live Hangout with New Horizons Team

And be sure to check out the New Horizons mission homepage at NASA.

July 15, 2015December 23, 2015 by Ken Kremer

NASA’s New Horizons Makes Major Discoveries: Young Ice Mountains on Pluto and Crispy Young Chasms on Charon

New close-up images of a region near Pluto’s equator reveal a giant surprise — a range of youthful mountains rising as high as 11,000 feet (3,500 meters) above the surface of the icy body. Credits: NASA/JHU APL/SwRI
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APPLIED PHYSICS LABORATORY, LAUREL, MD – Scientists leading NASA’s historic New Horizons mission to the Pluto system announced the first of what is certain to be a tidal wave of new discoveries, including the totally unexpected finding of young ice mountains at Pluto and crispy clear views of young fractures on its largest moon Charon, at a NASA media briefing today (July 15) at the Applied Physics Laboratory (APL) in Laurel, Maryland.

A treasure trove of long awaited data has begun streaming back to Mission Control at Johns Hopkins University Applied Physics Laboratory to the mouth watering delight of researchers and NASA.

With the first ever flyby of Pluto, America completed the initial up close reconnaissance of the planets in our solar system. Pluto was the last unexplored planet, building on missions that exactly started 50 years ago in 1965 when Mariner IV flew past Mars.

“Pluto New Horizons is a true mission of exploration showing us why basic scientific research is so important,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington.

“The mission has had nine years to build expectations about what we would see during closest approach to Pluto and Charon. Today, we get the first sampling of the scientific treasure collected during those critical moments, and I can tell you it dramatically surpasses those high expectations.”

Crisp new view of Pluto’s largest moon, Charon shows a swath of cliffs and troughs stretches about 600 miles (1,000 kilometers) from left to right, suggesting widespread fracturing of Charon’s crust, likely a result of internal processes. At upper right, along the moon’s curving edge, is a canyon estimated to be 4 to 6 miles (7 to 9 kilometers) deep. Credit: NASA-JHUAPL-SwRI

Today the team announced that New Horizons has already made a totally unexpected discovery showing clear evidence of ice mountains on Pluto’s surface in the bright area informally known as the ‘big heart of Pluto.’

The new close-up image released today showed an icy mountain range near the base of the heart with peaks jutting as high as 11,000 feet (3,500 meters) above the surface, announced John Spencer, New Horizons science team co-investigator at the media briefing.

“It’s a very young surface, probably formed less than 100 million years old,’ said Spencer. “It may be active now.”

Spencer also announce that the heart shaped region will now be named “Tombaugh Reggio” in honor of Clyde Tombaugh, the American astronomer who discovered Pluto in 1930.

“We are seeing water ice.”

“I never would have imagined this!” Spencer exclaimed.

“And I’m very surprised that there are no craters in the first high resolution images.”

Pluto nearly fills the frame in this image from the Long Range Reconnaissance Imager (LORRI) aboard NASA’s New Horizons spacecraft, taken on July 13, 2015 when the spacecraft was 476,000 miles (768,000 kilometers) from the surface. This is the last and most detailed image sent to Earth before the spacecraft’s closest approach to Pluto on July 14. The large, heart-shaped region is front and center. Several craters are seen and much of the surface looks reworked rather than ancient. Credit: NASA-JHUAPL-SwRI

The finding of ice mountains has major scientific implications.

Unlike the icy moons of giant planets, Pluto cannot be heated by gravitational interactions with a much larger planetary body. Some other process must be generating the mountainous landscape, said the team.

“This may cause us to rethink what powers geological activity on many other icy worlds,” says Spencer of SwRI.

NASA announces discovery of icy mountain ranges on Pluto at July 15 media briefing at Johns Hopkins University Applied Physics Laboratory. Credit: Ken Kremer/kenkremer.com

“Pluto may have internal activity. There may be geysers or cryovolcanoes,” New Horizons principal investigator Alan Stern of the Southwest Research Institute, Boulder, Colorado, said during the media briefing. However there is no evidence for them yet.

Additional high resolution images for “Tombaugh Reggio” area are being transmitted back to Earth today and will continue.

“Finding a mountain range of ice is a complete surprise,” Stern noted.

After a nine year voyage through interplanetary space, New Horizons barreled past the Pluto system on Tuesday, July 14 for a history making first ever flyby at over 31,000 mph (49,600 kph), and survived the passage by swooping barely 7,750 miles (12,500 kilometers) above the planet’s amazingly diverse surface.

The team had to wait another 12 hours for confirmation that the spacecraft lived through the daring encounter when signals were reacquired as planned at 8:53 p.m. EDT last night. Since New Horizons swung past Pluto to continue its voyage, the probe is now more than million miles outbound just 24 hours later.

NASA Associate Administrator for the Science Mission Directorate John Grunsfeld, left, New Horizons Principal Investigator Alan Stern of Southwest Research Institute (SwRI), Boulder, CO, second from left, New Horizons Mission Operations Manager Alice Bowman of the Johns Hopkins University Applied Physics Laboratory (APL), second from right, and New Horizons Project Manager Glen Fountain of APL, right, are seen at the conclusion of a press conference after the team received confirmation from the spacecraft that it has completed the flyby of Pluto, Tuesday, July 14, 2015 at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. Credit: Ken Kremer/kenkremer.com

The New Frontiers spacecraft was built by a team led by Stern and included researchers from SwRI and the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. APL also operates the New Horizons spacecraft and manages the mission.

NASA Administrator Charles Bolden congratulates the New Horizons team after successful Pluto flyby on July 14, 2015, to cheering crowd at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, during live NASA TV media briefing. Credit: Ken Kremer/kenkremer.com

Watch for Ken’s continuing onsite coverage of the Pluto flyby on July 14 from the Johns Hopkins University Applied Physics Laboratory (APL).

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

New Horizons science team co-investigator John Spencer examines print of the newest Pluto image taken on July 13, 2015 after the successful Pluto flyby. Credit: Ken Kremer/kenkremer.com

July 15, 2015December 23, 2015 by Ken Kremer

NASA’s New Horizons Zooms By Pluto, Solar Systems Last Planet – King of The Kuiper Belt

APPLIED PHYSICS LABORATORY, LAUREL, MD – With this morning’s (July 14) do or die flyby of Pluto by NASA’s New Horizons spacecraft at 7:49 a.m. EDT while traveling over 3 billion miles away, America completed the initial up close reconnaissance of the last explored planet of our solar system at its frigid, far flung reaches and revealed a remarkably differentiated world dazzling us with alien terrain far beyond anyone’s expectation.

New Horizons barreled past Pluto for a history making first ever flyby at over 31,000 mph (49,600 kph) and passed only 7,750 miles (12,500 kilometers) above the planet’s amazingly diverse surface.

To mark the occasion, NASA released the highest resolution image ever taken of Pluto as the probe swooped past its prey this morning, centered on the two lobed, differentiated ‘heart’.

But because the one ton piano shaped spacecraft has been out of touch with Mission Control for the past day as planned and busily gathering hordes of priceless data, confirmation of a successful flyby didn’t reach Mission Control on Earth until half a day later when New Horizons ‘phoned home’ with critical engineering data confirmed the health of the probe at 8:53 p.m. EDT this evening- basically saying “I’m Alive”.

“With this mission we have we have visited every planet in our solar system,” proclaimed NASA Administrator Charles Bolden this evening, July 14, to a packed house of cheering team members, invited guests and media including Universe Today at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, during a live NASA TV media briefing shortly after accomplishing the historic feat after the nine year interplanetary voyage.

“No other nation has that capability. It’s a historic day for exploration.”

“We did it! exclaimed New Horizons principal investigator Alan Stern of the Southwest Research Institute, Boulder, Colorado, during the live media briefing.

“That’s one small step for New Horizons, one giant leap for mankind,” Stern added, paraphrasing humanity’s first moonwalker, Neil Armstrong.

“New Horizons completes the first planetary reconnaissance, a capstone of our time.”

The Pluto flyby took place on the 50th anniversary of the first interplanetary flyby by America’s Mariner 4 spacecraft when it soared past Mars in 1965.

Pluto and Charon in False Color Show Compositional Diversity. This July 13, 2015, image of Pluto and Charon is presented in false colors to make differences in surface material and features easy to see. It was obtained by the Ralph instrument on NASA's New Horizons spacecraft, using three filters to obtain color information, which is exaggerated in the image. These are not the actual colors of Pluto and Charon, and the apparent distance between the two bodies has been reduced for this side-by-side view. Credit: NASA/APL/SwRI — Pluto and Charon in False Color Show Compositional Diversity. This July 13, 2015, image of Pluto and Charon is presented in false colors to make differences in surface material and features easy to see. It was obtained by the Ralph instrument on NASA’s New Horizons spacecraft, using three filters to obtain color information, which is exaggerated in the image. These are not the actual colors of Pluto and Charon, and the apparent distance between the two bodies has been reduced for this side-by-side view. Credit: NASA/APL/SwRI

“Today we inspired a whole generation of new explorers,” Bolden said to the crowd emotionally. “And you have more to do!” – as he pointedly acknowledge a crowd of young people in the room.

Pluto is covered by a spectacular array of craters, mountains, valleys, a whale shaped dark feature and a huge heart-shaped continent of pinkinsh bright ice as seen in the image taken on July 13 when the spacecraft was 476,000 miles (768,000 kilometers) from the surface.

“New Horizons has sent back the most detailed data ever of Pluto and its system of moons.”

“Every mission expands our horizons and bring us one step further on the Journey to Mars,” said Bolden regarding NASA’s agency wide plans to send astronauts to the Red Planet during the 2030s.

“You have made Pluto almost human.”

NASA Administrator Charles Bolden congratulates the New Horizons team after successful Pluto flyby on July 14, 2015 g, July 14, to cheering crowd at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, during live NASA TV media briefing. Credit: Ken Kremer/kenkremer.com — NASA Administrator Charles Bolden congratulates the New Horizons team after successful Pluto flyby on July 14, 2015, to cheering crowd at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, during live NASA TV media briefing. Credit: Ken Kremer/kenkremer.com

Tomorrow, the more than year long data playback begins.

“The best is yet to come,” said John Grunsfeld, NASA Associate Administrator for the Science Mission Directorate, at the media briefing.

“You haven’t seen anything yet. There are many more months of data to be sent back.”

“This is like the Curiosity landing. This is just the beginning for fundamental discoveries. It’s a tremendous moment in human history.”

New Horizons Principal Investigator Alan Stern celebrates in mission control after reception of signal from NASA’s New Horizons probe at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland after the successful Pluto flyby on July 14, 2015. Credit: Ken Kremer/kenkremer.com

Congratulations rolled in from around the world including President Obama and world renowned physicist Stephen Hawking.

It has been three decades since we last visited planetary bodies at the outer reaches of our solar system when Voyager 2 flew past Uranus and Neptune in 1986 and 1989.

Watch for Ken’s continuing onsite coverage of the Pluto flyby on July 14/15 from the Johns Hopkins University Applied Physics Laboratory (APL).

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

July 14, 2015December 23, 2015 by Bob King

New Horizons Phones Home, Flyby a Success

New Horizons Flight Controllers celebrate after they received confirmation from the spacecraft that it had successfully completed the flyby of Pluto, Tuesday, July 14, 2015 in the Mission Operations Center (MOC) of the Johns Hopkins University Applied Physics Laboratory (APL), Laurel, Maryland. Credit: NASA/Bill Ingalls

Watch Pluto grow in this series of photos taken during New Horizons’ approach

Whew! We’re out of the woods. On schedule at 9 p.m. EDT, New Horizons phoned home telling the mission team and the rest of the on-edge world that all went well. The preprogrammed “phone call” — a 15-minute series of status messages beamed back to mission operations at the Johns Hopkins University Applied Physics Laboratory in Maryland through NASA’s Deep Space Network — ended a tense 21-hour waiting period.

The team deliberately suspended communications with New Horizons until it was beyond the Pluto system, so the spacecraft could focus solely on data gathering. With a mountain of information now queued up, it’s estimated it will take 16 months to get it all back home. As the precious morsels arrive bit by byte, New Horizons will sail deeper into the Kuiper Belt looking for new targets until it ultimately departs the Solar System.

After Pluto, NASA hopes to send New Horizons to another asteroid or two in the Kuiper Belt and perform a flyby and reconnaissance similar to the Pluto mission. Credt: Alex Parker / SwRI — After Pluto, NASA hopes to send New Horizons to another asteroid or two in the Kuiper Belt to perform a flyby and reconnaissance similar to the Pluto mission. Credit: Alex Parker / SwRI

Assuming NASA funds a continuing mission, the team hopes to direct the spacecraft to one or two additional Kuiper Belt objects (KBO) over the next five to seven years. There are presently three possible targets – PT1, PT2, and PT3. (PT = potential target). PT1, imaged by the Hubble Space Telescope, looks like the best option at the moment and could by reached by January 2019. If you thought Pluto was small, PT 1 is only about 25 miles (40 km) across. Much lies ahead.

The image at left shows a KBO at an estimated distance of approximately 4 billion miles from Earth. Its position noticeably shifts between exposures taken approximately 10 minutes apart. The image at right shows a second KBO at roughly a similar distance. Credit: NASA, ESA, SwRI, JHU/APL, and the New Horizons KBO Search Team

July 14, 2015December 23, 2015 by Bob King

Pluto – Just Look at the Detail!

We did it! At 7:49 a.m. EDT today New Horizons made history when it zoomed within 7,800 miles of Pluto, the most remote object ever visited in the Solar System. I thought you’d like to see our best view yet of Pluto in this last and sharpest image taken before closest approach. The level of detail is fantastic.

Universe Today’s Ken Kremer is on the scene at mission control, and we’ll have much more news and analysis for you later today. For now, here’s a taste.

Members of NASA's New Horizons team react to seeing the latest image of Pluto. Credit: NASA — Members of NASA’s New Horizons team react to seeing the latest image of Pluto. Credit: NASA

Pluto encounter July 14th 11:00-12:00 UTC (6:00am CDT) by Tom Ruen

Efrain Morales created this fine document of Pluto seen from New Horizons and photographed at nearly — Efrain Morales created this fine document of the Pluto encounter by combining the recent New Horizons photo with images taken through his telescope about 6 1/2 hours before closest approach. Images taken on July 10 and 11 show Pluto’s slow crawl across the starfield. Credit: Efrain Morales

This graphic presents a view of Pluto and Charon as they would appear if placed slightly above Earth's surface and viewed from a great distance. Recent measurements obtained by New Horizons indicate that Pluto has a diameter of 2370 km, 18.5% that of Earth's, while Charon has a diameter of 1208 km, 9.5% that of Earth's. Credit: NASA/JHUAPL/SWRI — To give you a better idea of how small New Horizons’ targets are, this graphic shows Pluto and Charon as they would appear if placed slightly above Earth’s surface and viewed from a great distance. Recent measurements obtained by New Horizons indicate that Pluto has a diameter of 1,473 miles (2370 km, making it the largest known Kuiper Belt object, while Charon has a diameter of 751 miles (1208 km). Credit: NASA/JHUAPL/SWRI

Pluto has a very complex surface. The fact that large areas show few craters – as compared to say, Ceres or Vesta – shows that there have relatively recent changes there. Maybe very recent. Alan Stern, principal investigator for the mission, was asked by a report at this morning’s press conference if it snows on Pluto. His answer: “It sure looks like it.”

Mission principal investigator has reason to smile this morning during the press conference. So far, New Horizons is doing well. Credit: NASA-TV

Stern is also confident the spacecraft survived closest approach without getting bulleted by dust. We should know tonight when it “phones home” around 9 p.m. EDT.

Even Rosetta couldn't resist a look at Pluto. On July 12, the spacecraft took many images of the distant world and stacked them to create the photos above. Left: The unprocessed image is obscured by dust grains in Comet 67P/C-G’s coma. Middle: Pluto’s background of stars as seen from Rosetta. Right: The processed image shows Pluto as a bright spot within the blue circle. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA — Even Rosetta couldn’t resist a look at Pluto. On July 12, the spacecraft took many images of the distant world which were stacked to create the photos above. Left: The unprocessed image is obscured by dust grains in Comet 67P/C-G’s coma. Middle: Pluto’s background of stars as seen from Rosetta. Right: The processed image shows Pluto as a bright spot within the blue circle.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

With the Pluto flyby the latest achievement in over 50 years of humankind’s exploration of the Solar System’s wild assortment of moons, planets and comets, see the bounty of our efforts in this wonderful compendium titled From Pluto to the Sun by Jon Keegan, Chris Canipe and Alberto Cervantes.

July 14, 2015December 21, 2015 by Matt Williams

Charon: Pluto’s Largest Moon

Beginning in 1978, astronomers began to discover that Pluto – the most distant known object from the Sun (at the time) – had its own moons. What had once been thought to be a solitary body occupying the outer edge of our Solar System suddenly appeared to have a system with a large moon Charon. And as time went on, a total of four moons would be discovered.

Of these, Charon is the largest and most easily observed, hence why it was discovered first. In addition to being the biggest of its peers, its also quite large in comparison to Pluto. As such, Charon has always had something of a unique relationship with its parent body, and stands apart as far as objects in the outer Solar System are concerned.

Continue reading “Charon: Pluto’s Largest Moon”

July 13, 2015December 23, 2015 by Ken Kremer

Big Discovery from NASA’s New Horizons; Pluto is Biggest Kuiper Belt Body

A portrait from the final approach. Pluto and Charon display striking color and brightness contrast in this composite image from July 11, showing high-resolution black-and-white LORRI images colorized with Ralph data collected from the last rotation of Pluto. Color data being returned by the spacecraft now will update these images, bringing color contrast into sharper focus. Credits: NASA-JHUAPL-SWRI

Plutophiles everywhere rejoice. On the eve of history’s first ever up close flyby of mysterious Pluto on Tuesday morning July 14 making the first detailed scientific observations, NASA’s New Horizons has made a big discovery about one of the most basic questions regarding distant Pluto. How big is it?

Measurements by New Horizons gathered just in the past few days as the spacecraft barrels towards the Pluto planetary system now confirm that Pluto is indeed the biggest object in the vast region beyond the orbit of Neptune known as the Kuiper Belt.

Pluto is thus the undisputed King of the Kuiper Belt!

Pluto measures 1,473 miles (2,370 kilometers) in diameter, which is at the higher end of the range of previous estimates.

The big news was announced today, by New Horizons principal investigator Alan Stern of the Southwest Research Institute, Boulder, Colorado, during a live media briefing at Pluto mission control at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.

“This settles the debate about the largest object in the Kuiper Belt,” Stern noted.

New Horizons will swoop to within about 12,500 kilometers (nearly 7,750 miles) of Pluto’s surface and about 17,900 miles (28,800 kilometers) from Charon during closest approach at approximately 7:49 a.m. EDT (11:49 UTC) on July 14.

The new and definitive measurement of Pluto’s size is based on images taken by the high resolution Long Range Reconnaissance Imager (LORRI) to make this determination.

“The size of Pluto has been debated since its discovery in 1930. We are excited to finally lay this question to rest,” said mission scientist Bill McKinnon, Washington University, St. Louis.

Pluto was the first planet discovered by an American, Clyde Tombaugh.

Pluto’s “Heart” is seen in this new image from New Horizons’ Long Range Reconnaissance Imager (LORRI) received on July 8, 2015 after normal science operations resumed following the scary July 4 safe mode anomaly that briefing shut down all science operations. The LORRI image has been combined with lower-resolution color information from the Ralph instrument. Credits: NASA-JHUAPL-SWRI

Pluto is bigger than Eris, another big Kuiper Belt object discovered in 2005 by Mike Brown of Caltech, which is much further out from the Sun than Pluto. The discovery of Eris further fueled the controversial debate about the status of Pluto’s planethood.

Eris comes in second in size in the Kuiper Belt at only 1,445 miles (2,326 km) in diameter.

On July 11, 2015, New Horizons captured a world that is growing more fascinating by the day. For the first time on Pluto, this view reveals linear features that may be cliffs, as well as a circular feature that could be an impact crater. Rotating into view is the bright heart-shaped feature that will be seen in more detail during New Horizons’ closest approach on July 14. The annotated version includes a diagram indicating Pluto’s north pole, equator, and central meridian. Credits: NASA/JHUAPL/SWRI — On July 11, 2015, New Horizons captured a world that is growing more fascinating by the day. For the first time on Pluto, this view reveals linear features that may be cliffs, as well as a circular feature that could be an impact crater. Rotating into view is the bright heart-shaped feature that will be seen in more detail during New Horizons’ closest approach on July 14. The annotated version includes a diagram indicating Pluto’s north pole, equator, and central meridian.
Credits: NASA/JHUAPL/SWRI

Stern also noted that because Pluto is slight bigger than the average of previous estimates, its density is slightly lower than previously thought. Therefore the fraction of ice in its interior is slightly higher and the fraction of rock is slightly lower. But further data is required to pin the density down more precisely.

The uncertainty in Pluto’s size has persisted for decades and was due to the fact that Pluto has a very tenuous atmosphere composed of nitrogen.

Furthermore Pluto’s lowest atmospheric layer called the troposphere, is shallower than previously believed.

On the other hand, its largest moon Charon with which it forms a double planet, lacks a substantial atmosphere and its size was known with near certainty based on ground-based telescopic observation.

New Horizons LORRI imagery has confirmed that Charon measures 751 miles (1208 km) kilometers) across.

Stern also confirmed that frigid Pluto also has a polar cap composed of methane and nitrogen ices based on measurements from the Alice instrument.

LORRI has also zoomed in on two of Pluto’s smaller moons, Nix and Hydra.

“We knew from the time we designed our flyby that we would only be able to study the small moons in detail for just a few days before closest approach,” said Stern. “Now, deep inside Pluto’s sphere of influence, that time has come.”

The approximate sizes of Pluto’s moons Nix and Hydra compared to Denver, Colorado. While Nix and Hydra are illustrated as circles in this diagram, mission scientists anticipate that future observations by New Horizons will show that they are irregular in shape. Credits: JHUAPL/Google

But because they are so small, accurate measurement with LORRI could only be made in the final week prior to the July 14 flyby.

Nix is estimated to be about 20 miles (about 35 kilometers) across, while Hydra is roughly 30 miles (roughly 45 kilometers) across. These sizes lead mission scientists to conclude that their surfaces are quite bright, possibly due to the presence of ice.

Determinations about Pluto’s two smallest moons, Kerberos and Styx, will be made later at some point during the 16-month long playback of data after the July 14 encounter.

It has been three decades since we last visited planetary bodies at the outer reaches of our solar system when Voyager 2 flew past Uranus and Neptune in 1986 and 1989.

New Horizons' last look at Pluto's Charon-facing hemisphere reveals the highest resolution view of four intriguing darks spots for decades to come. 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. Credit: NASA/JHUAPL/SWRI — New Horizons’ last look at Pluto’s Charon-facing hemisphere reveals the highest resolution view of four intriguing darks spots for decades to come. 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. Credit: NASA/JHUAPL/SWRI

New Horizons is closing in fast on its quarry at a whopping 31,000 mph (49,600 kph) after a nine year interplanetary voyage and is now less than half a million miles away, in the final hours before closest approach.

Watch for Ken’s continuing onsite coverage of the Pluto flyby on July 14 from the Johns Hopkins University Applied Physics Laboratory (APL).

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

July 13, 2015February 6, 2017 by Matt Williams

Pluto’s Moon Hydra

The Pluto system seen from the surface of Hydra. Credit: NASA

In 1930, Pluto was observed for the first time. For many decades, astronomers thought that the “ninth planet of the Solar System” was a solitary object. But by 1978, astronomers discovered that it also had a moon roughly half its size. This moon would come to be known as Charon, and it would be the first of many discoveries made within the Pluto’s system.

In fact, within the last decade, four additional satellites have been discovered in orbit of Pluto. Of these, the outermost to be observed is the moon now known as Hydra.

Discovery:
Hydra was first discovered in June 2005 by the Hubble Space Telescope‘s “Pluto Companion Search Team”, using images that were taken on May 15th and 18th of that year. At the time, the team was preparing for the launch of the New Horizons mission to Pluto, seeking to gain as much information as they could about any addition Plutonian moons.

By June, Hydra was again discovered. This time, it was independently observed by two members of the team, along with Nix – another small Plutonian moon. The discoveries were announced on October 31st, 2005, and were provisionally given the designations of S/2005 P 1 and S/2005 P 2 (for Hydra and Nix, respectively).

This illustration shows the scale and comparative brightness of Pluto’s small satellites. The surface craters are for illustration only and are not real. Credits: NASA/ESA/A. Feild (STScI) — *Artist’s illustration comparing the scale and comparative brightness of Pluto’s small satellites.*
*Credits: NASA/ESA/A. Feild (STScI)*

Name:
By June 21st, 2006, the name Hydra was assigned by the IAU (along with the formal designation Pluto III). The name Hydra, which is derived from the nine-headed serpent of Greek mythology, was selected for two reasons. The letter H refers to the Hubble Telescope, which was used to make the discovery, while the nine-headed serpent referred to Pluto’s tenure as the ninth planet of the Solar System.

Size, Mass and Orbit:
Although its size has not been directly measured, calculations based on its brightness have indicated that Hydra’s diameter is between 40 and 160 kilometers (38 and 104 mi). Similar measurements estimate its mass to be in the vicinity of 4.2 x 10¹⁷ kg. Because of the uncertainty in these measurements, Hydra is either comparable in size to either the main moons of Saturn and Neptune, or the inner and irregular moons of Jupiter, Saturn and Uranus.

Hydra orbits Pluto at a distance of about 65,000 km with a very low eccentricity (0.0059) and an orbital inclination of about 0.24°. It orbits in the same plane as Charon and Nix and has an orbital period of 38.2 days.

Composition:
Little is known about Hydra’s composition, and its density and albedo are both currently unknown. However, it is believed that if its diameter is towards the lower end of its estimated range (40 km), then it must have a geometric albedo similar to Charons (35%).

*Labeled image of Hydra released upon IAU name approval. Credit: NASA/ESA/Hubble*

However, assuming it is at the higher end of that range, it would likely have a reflectivity of about 4%, like the darkest Kuiper belt objects. Like all outer bodies in the outer Solar System, and its host planet Pluto, it is possible that Hydra’s composition is differentiated into a rocky core and an icy mantle that contains nitrogen and methane in ice form.

At the time of its discovery, Hydra appeared to be brighter than Nix. Observations made with the Hubble Telescope in 2005–06, which specifically targeting the two moons, once again confirmed that Hydra is the brighter of the two. Hydra appears to be spectrally neutral like Charon and Nix (i.e. greyish), whereas Pluto is reddish.

Interesting Facts:
Hydra, not being massive enough to form a spheroid under its own gravity, is believed to be oblong in shape – the same holds true for Pluto’s moon of Nix. As with the rest of the Pluto system, Hydra was imaged by NASA’s New Horizons spacecraft in February of 2015. When New Horizons conducts its flyby at 7:49:57 a.m. EDT, July 14, 2015, it will provide the most detailed images of Hydra and the Pluto system to date.

We have several interesting articles on Pluto’s moon of Hydra. Here’s one on the First New Images of Pluto from New Horizons, and New Horizons Now Close Enough to See Pluto’s Smaller Moons.

For more information on the constellation of Hydra, click here. For more information on New Horizons mission to Hydra, click here.

July 13, 2015December 23, 2015 by David Dickinson

Naming Pluto: Christening Features on Brave New Worlds

Artist's impression of Charon (left) and Pluto (right), showing their relative sizes. Credit:

‘Here be Dragons…’ read the inscriptions of old maps used by early seafaring explorers. Such maps were crude, and often wildly inaccurate.

The same could be said for our very understanding of distant planetary surfaces today. But this week, we’ll be filling in one of those ‘terra incognita’ labels, as New Horizons conducts humanity’s very first reconnaissance of Pluto and its moons.

The closest approach for New Horizons is set for Tuesday, July 14^th at 11:49 UT/7:49 AM EDT, as the intrepid spacecraft passes 12,600 kilometres (7,800 miles) from Pluto’s surface. At over 4 light hours or nearly 32 astronomical units (AUs) away, New Horizons is on its own, and must perform its complex pirouette through the Pluto system as it cruises by at over 14 kilometres (8 miles) a second.

This also means that we’ll be hearing relatively little from the spacecraft on flyby day, as it can’t waste precious time pointing its main dish back at the Earth. With a downlink rate of 2 kilobits a second—think ye ole 1990’s dial-up, plus frozen molasses—it’ll take months to finish off data retrieval post flyby. A great place to watch a simulation of the flyby ‘live’ is JPL’s Eyes on the Solar System, along with who is talking to New Horizons currently on the Deep Space Network with DSN Now.

A snapshot of the current July 13th view of New Horizons as it nears Pluto. (Image credit: NASA's Eyes on the Solar System). — A snapshot of the current July 13th view of New Horizons as it nears Pluto. (Image credit: NASA’s Eyes on the Solar System).

Launched in 2006, New Horizons is about to join the ranks of nuclear-fueled explorers that have conducted first time reconnaissance of solar system objects.

Bob King also wrote up an excellent timeline of New Horizons events for Universe Today yesterday. Also be sure to check out the Planetary Society’s in-depth look at what to expect by Emily Lakdawalla.

Seems strange that after more than a decade of recycling the same blurry images and artist’s conceptions in articles, we’re now getting a new and improved shot of Pluto and Charon daily!

To follow the tale of Pluto is to know the story of modern planetary astronomy. Discovered in 1930 by American astronomer Clyde Tombaugh from the Lowell Observatory, Pluto was named by 11-year old Venetia Burney. Venetia just passed away in 2009, and there’s a great short documentary interview with her entitled Naming Pluto.

Blink comparitor — The blink comparitor Clyde Tombaugh used to discover Pluto, on display at the Lowell Observatory. Image Credit: David Dickinson

Fun fact: Historians at the Carnegie Institute recently found images of Pluto on glass plates… dated 1925, from five years before its discovery.

Despite the pop culture reference, Pluto was not named after the Disney dog, but after the Roman god of the underworld. Pluto the dog was not named in Disney features until late 1930, and if anything, the character was more than likely named after the buzz surrounding the newest planet on the block.

We’re already seeing features on Pluto and Charon in the latest images, such as the ‘heart,’ ‘donut,’ and the ‘whale’ of Pluto, along with chasms, craters and a dark patch on Charon. The conspicuous lack of large craters on Pluto suggests an active world.

The International Astronomical Union (IAU) convention for naming any new moons discovered in the Plutonian system specifies characters related to the Roman god Pluto and tales of the underworld.

Brake for New Horizons on July 14th… Image credit: David Dickinson

With features, however, cartographers of Pluto should get a bit more flexibility. Earlier this year, the Our Pluto campaign invited the public to cast votes to name features on Pluto and Charon related to famous scientists, explorers and more. The themes of ‘fictional explorers and vessels’ has, of course, garnered much public interest, and Star Trek’s Mr. Spock and the Firefly vessel Serenity may yet be memorialized on Charon. Certainly, it would be a fitting tribute to the late Leonard Nimoy. We’d like to see Clyde Tombaugh and Venetia Burney paid homage to on Pluto as well.

We’ve even proposed the discovery of a new moon be named after the mythological underworld character Alecto, complete with a Greek ‘ct’ spelling to honor Clyde Tombaugh.

The discovery and naming of Charon in 1978 by astronomer Robert Christy set a similar precedent. Christy choose the name of the mythological boatman who plied the river Styx (which also later became a Plutonian moon) as it included his wife Charlene’s nickname ‘Char.’ This shibboleth also set up a minor modern controversy as to the exact pronunciation of Charon, as the mythological character is pronounced with a hard ‘k’ sound, but most folks (including NASA) say the moon as ‘Sharon’ in keeping with Christy’s in-joke that slipped past the IAU.

And speaking of Pluto’s large moon, someone did rise to the occasion and take our ‘Charon challenge,’ we posed during the ongoing Pluto opposition season recently. Check out this amazing capture of the +17^th magnitude moon winking in and out of view next to Pluto courtesy of Wendy Clark:

Clark used the 17” iTelescope astrograph located at Siding Spring Observatory in Australia to tease out the possible capture of the itinerant moon.

Great job!

What’s in a name? What strange and wonderful discoveries await New Horizons this week? We should get our very first signal back tomorrow night, as New Horizons ‘phones home’ with its message that it survived the journey around 9:10 PM EDT/1:10 UT. Expect this following Wednesday—in the words of New Horizons principal Investigator Alan Stern—to begin “raining data,” as the phase of interpreting and evaluating information begins.

And there’s more in store, as the New Horizons team will make the decision to maneuver the spacecraft for a rendezvous with a Kuiper Belt Object (KBO) next month. Said KBO flyby will occur in the 2019-2020 timeframe, and perhaps, we’ll one day see a Pluto orbiter mission or lander in the decades to come…

Maybe one way journeys to ‘the other Red Planet’ are the wave of the future.’ Pluto One anyone?

July 12, 2015December 23, 2015 by Ken Kremer

Charon Up Close Reveals Colossal Chasms and Craters: 1 Day and 1 Million Miles Out from Pluto Flyby

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. The annotated version includes a diagram showing Charon’s north pole, equator, and central meridian, with the features highlighted. Credits: NASA/JHUAPL/SWRI
Story/imagery updated[/caption]

In the final days before humankinds first ever flyby of mysterious and tantalizing Pluto for the history making up close visit on Tuesday, July 14, NASA’s New Horizons spacecraft has just delivered the sharpest and most stunning view yet of its binary companion Charon – and unveiled it to be a geologically rich world with colossal chasms, a multitude of craters and a humongous dark splotch in the northern regions. It’s obviously quite different in appearance and varies in composition from its larger planetary host.

Indeed the largest of Charon’s chasms stretches farther than Earth’s Grand Canyon. And it’s taken New Horizons over nine years speeding through space – since launching back in 2006 as the fastest spacecraft departing Earth – to get close enough to see these wonders for the first time.

“The most pronounced chasm, which lies in the southern hemisphere, is longer and miles deeper than Earth’s Grand Canyon,” says William McKinnon, deputy lead scientist with New Horizon’s Geology and Geophysics investigation team, in a NASA statement.

To put that into perspective, consider this; Charon is only about 750 miles (1200 kilometers) across, about half the diameter of Pluto. The Grand Canyon stretches 277 miles (446 km) across the western United States and is up to 18 miles (29 km) wide and attains a depth of over a mile (6093 feet or 1857 meters). Thus Charon’s ‘Grand Canyon’ is truly gargantuan in comparison to its moons size when compared to our Grand Canyon.

At 1471 miles (2368 km) across, Pluto is about half the diameter of the United States. Both Pluto and Charon and largely composed of icy materials, with much less rock compared to the terrestrial planets like Earth.

“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.”

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

The exquisite new image of Charon’s chasms and canyons was just released by NASA this evening, Sunday, July 12. It was taken yesterday, Saturday, July 11, by New Horizons Long Range Reconnaissance Imager (LORRI) at a distance of 2.5 million miles (4 million kilometers) from Pluto and Charon, and radioed back to Earth today.

The largest crater seen in the July 11 images lies near Charon’s south pole and is about 60 miles (96.5 kilometers) across.

“The brightness of the rays of material blasted out of the crater suggest it formed relatively recently in geologic terms, during a collision with a small body some time in the last billion million years,” says the team.

“The darkness of the crater’s floor is especially intriguing,” says McKinnon.

“One explanation is that the crater has exposed a different type of icy material than the more reflective ices that lie on the surface. Another possibility is that the ice in the crater floor is the same material as its surroundings but has a larger ice grain size, which reflects less sunlight. In this scenario, the impactor that gouged the crater melted the ice in the crater floor, which then refroze into larger grains.”

New Horizons is now merely one day and one million miles (1.6 million km) out from its history making encounter with the Pluto planetary system – some three billion miles (4.8 billion km) from Earth. It passed the million mile milestone at 11:23 p.m. EDT, Sunday night July 12.

And its closing in fast on its quarry at a whopping 31,000 mph (49,600 kph) after a nine year interplanetary voyage.

The high resolution LORRI imager is achieving an image resolution of 5 mile per pixel at this moment at a million miles away. And it will gets thousands of times better during the closest approach.

“Features as small as the lakes in New York’s Central Park and wharfs on the Hudson will be resolved,” said New Horizons principal investigator Alan Stern of the Southwest Research Institute, Boulder, Colorado, during a live mission update today, July 12. The image resolution will reach a maximum of about 230 feet (70 meters).

New Horizons suite of seven science instruments will collected 44 gigabits of data during the flyby encounter period lasting from July 7 to July 16, from Pluto, Charon and the four tiny moons – Hydra, Styx, Nix and Kerberos.

Pluto and Charon are gravitationally locked with an orbital period of 6.4 days, so they always show the same face to one another. They orbit about 12,160 mi (19,570 kilometers) apart but about a center of gravity, or barycenter, above the surface of Pluto, unlike any of the other major bodies in our solar system.

Image of Pluto and Charon from July 8, 2015; color information obtained earlier in the mission from the Ralph instrument has been added. Credits: NASA-JHUAPL-SWRI

Charon is by far the largest of Pluto’s five moons. The new July 11 image also shows that it sports a “mysterious dark region” stretching some 200 miles across near the north pole.

Pluto is the last of the nine classical planets to be explored up close and completes the initial the initial reconnaissance of the solar system nearly six decades after the dawn of the space age. It represents a whole new class of objects known as the ice dwarfs, located in the Kuiper Belt – a relic of solar system formation replete with countless bodies.

It has been three decades since we last visited planetary bodies at the outer reaches of our solar system when Voyager 2 flew past Uranus and Neptune in 1986 and 1989.

New Horizons trajectory to the Pluto System. Credit: NASA

Watch for Ken’s continuing onsite coverage of the Pluto flyby on July 14 from the Johns Hopkins University Applied Physics Laboratory (APL).

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer