Where New Horizons is

[orin stepanek]

Latest report; Putting it all together! http://pluto.jhuapl.edu/overview/Scienc ... 07_24_2014

[orin stepanek]

Update!

Discoveries and Mysteries

July 31, 2014

Richard Binzel
New Horizons co-investigator

It is spine-tingling to be on the threshold of discovery for the most ambitious and farthest-exploring planetary encounter ever flown. A first time happens only once. There was the first time Galileo turned his telescope to the heavens, spotting craters on the moon, the moons of Jupiter, and the amazing rings of Saturn. All of those findings transformed our view of the solar system, and New Horizons could be similarly transformational.

Pluto is a world that has been only barely glimpsed with the Earth’s most capable telescopes. It almost feels like a fuzzy curtain is about to be pulled back next year, allowing Pluto to become a real place, with real features and characteristics that will define an entirely new region of our planetary system.

For many of us who have studied Pluto for decades and have had a role in making the New Horizons mission become a reality, standing on the threshold of revelation is surreal. Is this moment, one we have worked for so hard and for so long, really here? Pinch me!

When people ask me, “What do you expect to see?” I simply answer that I do not know. Quite deliberately, I try not to have a preconceived view because nature is always smarter and more complex than we can imagine. All that I know is that we will be surprised, amazed and befuddled. For all of us on New Horizons it will be our Olympic moment, set in motion almost 85 years ago by Clyde Tombaugh’s moment of discovery in 1930. There in the spotlight, with the public riding along with us, will come a myriad of questions as we unveil this new planetary system: What do you see? How do you explain it?

The thrill of discovery for me is in all the answers and new mysteries to be born.

Richard Binzel, a member of the New Horizons science team from Massachusetts Institute of Technology, is an expert in planetary photometry, spectroscopy and mapping. He is crafting plans for New Horizons' mapping of Pluto and coordinating an Earth-based observation campaign to coincide with the spacecraft's July 2015 flight through the Pluto system. (Photo credit: Barry Hetherington)

[bystander]

ALMA Pinpoints Pluto to Help Guide NASA's New Horizons Spacecraft
National Radio Astronomy Observatory | 2014 Aug 05

Animated image of ALMA data showing the motion of the moon Charon around the icy dwarf planet Pluto. [b][i](Credit: B. Saxton (NRAO/AUI/NSF))[/i][/b]

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Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) are making high-precision measurements of Pluto's location and orbit around the Sun to help NASA’s New Horizons spacecraft accurately home in on its target when it nears Pluto and its five known moons in July 2015.

Though observed for decades with ever-larger optical telescopes on Earth and in space, astronomers are still working out Pluto's exact position and path around our Solar System. This lingering uncertainty is due to Pluto's extreme distance from the Sun (approximately 40 times farther out than the Earth) and the fact that we have been studying it for only about one-third of its orbit. Pluto was discovered in 1930 and takes 248 years to complete one revolution around the Sun.

“With these limited observational data, our knowledge of Pluto’s position could be wrong by several thousand kilometers, which compromises our ability to calculate efficient targeting maneuvers for the New Horizons spacecraft,” said New Horizons Project Scientist Hal Weaver, from the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. ...

[neufer]

[b][color=#0000FF]Pluto & Charon with the Long Range Reconnaissance Imager (LORRI) instrument with ~ half Hubble resolution at this distance. Credit NASA / JHUAPL / SwRI[/color][/b]

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Twinkling worlds in motion: New Horizons' first optical navigation images of Pluto and Charon
Posted by Emily Lakdawalla 2014/08/07 19:31 UTC

[orin stepanek]

Twinkling worlds in motion: New Horizons' first optical navigation images of Pluto and Charon
Posted by Emily Lakdawalla 2014/08/07 19:31 UTC

http://pluto.jhuapl.edu/news_center/news/20140807.php

[orin stepanek]

Where is Pluto? http://pluto.jhuapl.edu/overview/Scienc ... 08_08_2014
Where Is Pluto?

August 8, 2014

Marc Buie
New Horizons co-investigator

New Horizons has traveled (nearly) nine long years to get across the solar system to check out Pluto – and it’s actually harder than you might think to make sure that Pluto will be there to greet us at the end of our journey. Sure, we've been studying Pluto since 1930 – but that's only a third of Pluto “year.” To get all the great data we've been planning for, we really want to make sure we know where Pluto is.

What's so hard? Well, we can measure Pluto's position in the sky pretty easily. But it’s much harder to figure out exactly how far away it is. We could observe it for a couple of Pluto years – about 500 Earth years – but that would take too long. To tackle this problem I dug into the archives at Lowell Observatory in Arizona, where Pluto was discovered. Astronomer Carl Lampland started taking pictures of Pluto right after its discovery in 1930, and helped with the early work to pin down Pluto's orbit. He continued this work for 21 years until his death and left behind an untapped legacy of work. By combining his old images with high-quality modern star catalogs, we can go back in time and get better positions of Pluto dating back to 1930.

Working with Jonathan Grindlay and his team at the Harvard-Smithsonian Center for Astrophysics and William Folkner at NASA’s Jet Propulsion Laboratory, we have been able to get new (old) positions of Pluto and use them to significantly improve on where we think Pluto is. With this improvement, the team driving New Horizons can tweak its flight to get to the right place at the right time. At this point we think we know where Pluto is to within about 1,000 kilometers, or about 620 miles. Considering that Pluto is about 4.5 billion kilometers from Earth, that's doing pretty well indeed, good enough for all the plans we've developed for looking at Pluto when New Horizons arrives in July 2015.

[orin stepanek]

latest news!
http://www.nasa.gov/sites/default/files ... iPrint.pdf

[orin stepanek]

Headlines
New Horizons Event: Crossing Neptune’s Orbit, Continuing Voyager’s Legacy of Exploration

August 22, 2014

On Aug. 25, NASA’s New Horizons spacecraft passes the orbit of Neptune, its last orbit crossing before beginning its historic exploration of Pluto in January 2015. By a celestial mechanics coincidence, the crossing occurs on the exact 25th anniversary of the Voyager 2 spacecraft’s encounter with Neptune in 1989. To commemorate Voyager’s achievements and the future discoveries of New Horizons, NASA will hold a two-part science event for the public to learn about the New Horizons mission and the spacecraft connection to Voyager’s historic visit to Neptune.

Media and the public are invited to attend the events on Monday, Aug. 25, from 1-3 p.m. (EDT) in the Webb Auditorium at NASA Headquarters, 300 E Street SW in Washington. The program will air live on NASA Television and the agency's website, http://www.nasa.gov.

The 1-2 p.m. event will feature a panel discussion with:

•Jim Green, director, NASA Planetary Division, Science Mission Directorate, NASA Headquarters, Washington
•Ed Stone, Voyager project scientist, California Institute of Technology, Pasadena
•Alan Stern, New Horizons principal investigator, Southwest Research Institute, Boulder, Colorado
The 2-3 p.m. event will include several New Horizons science team members giving personal accounts of their work during the Voyager Neptune encounter and their new assignments on the Pluto mission. Panel participants include:

•Moderator: David Grinspoon, Planetary Science Institute, Tucson, Arizona
•Fran Bagenal, University of Colorado, Boulder
•Bonnie Buratti, NASA Jet Propulsion Laboratory, Pasadena, California
•Jeffrey Moore, NASA Ames Research Center, Moffett Field, California
•John Spencer, Southwest Research Institute, Boulder, Colorado
Media can ask questions from participating NASA locations, or by telephone. To participate by phone, reporters must contact Steve Cole at (202) 358-0918 or stephen.e.cole@nasa.gov and provide their media affiliation by noon Monday.

Media and the public can also ask questions via social media using #askNASA.

For NASA TV streaming video, schedules and downlink information, visit:
http://www.nasa.gov/nasatv

For more information about New Horizons on the Internet, visit:
http://www.nasa.gov/newhorizons

[orin stepanek]

Science Shorts

Insights from members of the New Horizons Science Team
Pluto’s Complex Chemistry

September 4, 2014

Dale Cruikshank
New Horizons Co-Investigator

What is Pluto made of? With our telescopes on Earth, we have been able to discover that Pluto’s surface is covered by several kinds of ice – not frozen water, but frozen methane (“natural gas”), frozen carbon monoxide, frozen nitrogen, and a frozen hydrocarbon known as ethane. Frozen water must also be present, but it appears to be “bedrock” that is mostly covered by the other ices just noted.

The first inkling of Pluto’s surface composition came in 1976, when my colleagues and I found the evidence for methane, and I have been involved in finding all the other molecules that we have identified so far. Pluto’s very low temperature means that nearly any chemical present there is frozen solid on the surface, although there is still a thin gaseous atmosphere surrounding the planet. Pluto is exposed to ultraviolet radiation from the sun and cosmic rays from deep space, and this should produce additional and more complex chemicals, such as other hydrocarbons and hydrogen cyanide.

New Horizons will give us an opportunity to find other kinds of ice that are expected on the surfaces of both Pluto and its moon Charon, using the technique of infrared spectroscopy afforded by the LEISA component of the Ralph instrument aboard the spacecraft.

Ices are normally colorless, but Pluto has a reddish tint that probably arises from chemicals that are formed on its surface by the radiation acting on the different kinds of ice that we have already identified. Cosmic rays and ultraviolet light break up simple molecules into fragments that reassemble into more complex molecules. In the lab we see that this process results in colored solid material that has a chemical similarity to tar or coal, although tar and coal on Earth originate by entirely different processes. Lab experiments show that if this complex organic material is exposed to liquid water, it transforms into molecules like amino acids, which are thought to be the precursors of life on Earth. Ultraviolet spectroscopy with the Alice instrument may help us detect such material. We don’t expect life on Pluto, of course, but it may be one of the many bodies in space where complex organic chemistry of the kind that occurred on the early Earth is happening now.

In the mid-1970s, (from left) David Morrison, Carl Pilcher and Dale Cruikshank aimed the 4-meter Mayall Telescope and its powerful spectrometer (located at Kitt Peak National Observatory in Arizona) at Pluto and recorded the signature, or spectral fingerprint, of frozen methane. This discovery was the first indication that Pluto's surface is icy rather than rocky, and opened an era of investigations into the realm of small, icy, outer solar system objects that continues today.
Dale Cruikshank, an astronomer and planetary scientist at NASA Ames Research Center who specializes in spectroscopy and radiometry of planets and small bodies, will focus on the composition of the surfaces of Pluto and Charon. His expertise covers infrared spectroscopy and radiometry of planets, planetary satellites, asteroids, comets and transneptunian bodies, as well as physics and chemistry of ices and organic materials in planetary settings.

http://pluto.jhuapl.edu/overview/Scienc ... 09_04_2014

[bystander]

New Horizons Event: Crossing Neptune’s Orbit, Continuing Voyager’s Legacy of Exploration

Click to view full size image 1 or image 2

Distant Neptune: The New Horizons spacecraft captured this view of the giant planet Neptune and its large moon Triton on July 10, 2014, from a distance of about 2.45 billion miles (3.96 billion kilometers) - more than 26 times the distance between the Earth and sun. The 967-millisecond exposure was taken with the New Horizons telescopic Long-Range Reconnaissance Imager (LORRI).

New Horizons traverses the orbit of Neptune on Aug. 25, 2014 – its last planetary orbit crossing before beginning an encounter with Pluto in January 2015. In fact, at the time of the orbit crossing, New Horizons was much closer to its target planet – just about 273 million miles (or 440 million kilometers) – than to Neptune.

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

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NASA/JPL-Caltech: NASA Pluto-Bound Spacecraft Crosses Neptune's Orbit

JHU-APL: New Horizons Crosses Neptune Orbit En Route to Historic Pluto Encounter

Science@NASA: New Horizons Crosses the Orbit of Neptune

[orin stepanek]

Science Shorts

Insights from members of the New Horizons Science Team
Awaiting New Results on Pluto’s Atmosphere

September 11, 2014

Randy Gladstone
New Horizons Co-Investigator

What is Pluto’s atmosphere like? It seems like I’ve been wondering about that for decades! We’ve known so little for so long about Pluto’s atmosphere – other than it’s low-pressure, made mostly of molecular nitrogen (with a little methane and carbon monoxide mixed in) and may be quite extended – it’s nice to realize that we’ll know a whole lot more after New Horizons visits in summer 2015.

My professional interests on New Horizons lie with Pluto’s upper atmosphere – what it’s made of, how it interacts with space, and how it is processed by sunlight into different gases and aerosols. A problem in planning atmospheric observations for New Horizons during the flyby is that we really don’t know what to expect. Only a few models have been made that try to predict the composition of Pluto’s atmosphere, and they don’t agree very much with each other because of the many present uncertainties. So our plans generally include a lot of survey-type observations, where we try not to assume too much about what we will detect, but are ready for anything.

The best example of this is the Pluto solar occultation observation. The Alice ultraviolet spectrograph will watch the Sun set (and then rise again) as New Horizons flies through Pluto’s shadow, about an hour after closest approach. Watching how the different colors of sunlight fade (and then return) as New Horizons enters (and leaves) the shadow will tell us nearly all we could ask for about composition (all gases have unique absorption signatures at the ultraviolet wavelengths covered by Alice) and structure (how those the absorption features vary with altitude will tell us about temperatures, escape rates and possibly about dynamics and clouds).

When the New Horizons data start coming down, these are the data I’ll be waiting for the most!


Artist’s impression of Pluto, with its wispy atmosphere. Data from New Horizons’ Alice ultraviolet spectrograph will answer a full range of questions about the composition and structure of that atmosphere.
Randy Gladstone, of the Southwest Research Institute, leads the atmospheres theme group on the New Horizons Science Team. An expert in planetary aeronomy (studies of the upper atmosphere) and radiative transfer, he also serves on the Alice instrument team.

Click to view full size image

View The Science Shorts Archive >

http://pluto.jhuapl.edu/overview/Scienc ... 09_11_2014

[orin stepanek]

New Horizons locates Hydra; http://pluto.jhuapl.edu/news_center/news/20140912.php

Headlines
New Horizons Makes its First Detection of Pluto’s Moon Hydra

September 12, 2014

Using its Long Range Reconnaissance Imager (LORRI), New Horizons made its first detection of Pluto's small, faint, outermost known moon, Hydra. The images were taken to practice the long-exposure mosaics that the New Horizons team will use to search for additional moons and potentially hazardous debris near Pluto as the spacecraft approaches the Pluto system in May and June 2015.

Analysis of those images in September by Science Team members John Spencer, of the Southwest Research Institute, and Hal Weaver, of the Johns Hopkins Applied Physics Laboratory, revealed Hydra —a moon the mission didn’t expect to detect until next January, when New Horizons will be about twice as close as it was in July.

To detect Hydra, New Horizons took 48, 10-second images of Pluto on July 18 and again on July 20; the team combined half of them (which offered the best views of Hydra) to produce the very sensitive images on the dates shown. Pluto is the bright overexposed blob near the center of the image – the dark streak emerging to the right is a camera artifact caused by the intentional overexposure. The images on the two dates appear almost identical, but the difference between them is shown on the right. This “difference” image removes the crowded background of stars that doesn’t change between images. Hydra, which has moved over the two days, is revealed as an overlapping pair of bright and dark spots just above Pluto. The bottom row shows the same images with Hydra's expected position on the two dates, identified in each image by the red and green crosshairs. Hydra's motion can just be seen at the expected location in the original images. Pluto's next-brightest small moon, Nix, is closer to Pluto and cannot yet be separated from Pluto's glare.

“I’m excited about this first detection of Hydra,” says Principal Investigator Alan Stern, of the Southwest Research Institute. “It came as a bit of a bonus from this summer’s spacecraft activities.”

The processing tools used to combine the images and look for moving targets are the same ones that the team will use to search for much smaller “new” moons when New Horizons is much closer to Pluto. New Horizons was still 267 million miles (430 million kilometers) from Pluto when the pictures were taken, and the fact that it can already see Hydra was an encouraging test of the team's ability to find faint moons on the final approach to Pluto.

“Using those techniques, Hydra popped right out of the data, though it's still very faint – several times fainter than the faintest objects the New Horizons camera was designed to detect – and still very close to Pluto,” Spencer says. “We're thrilled to see it, because it shows that our satellite-search techniques work, and that our camera is operating superbly. But it's also exciting just to see a third member of the Pluto system come into view, as proof that we're almost there!”




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

[orin stepanek]

One Last Slumber! http://pluto.jhuapl.edu/overview/piPers ... 09_18_2014

September 18, 2014

Click to view full size image

On Aug. 25, New Horizons crossed the orbit of Neptune—the last planetary orbit crossing during cruise. Now we’re outbound for the frontier!

On Aug. 29 we put New Horizons into hibernation for the final time. This last hibernation lasts 99 days and ends on Dec. 6. It’s a little hard for some of us on the mission team to believe that after seven-plus years of hibernating through most of the 2.5-billion mile journey from Jupiter to Pluto and the inner reaches of the Kuiper Belt, the final, short leg of cruise is actually upon us.

We will wake New Horizons for the last time in just 10 weeks! When we do that, encounter preparations will begin, and six weeks later, the Pluto encounter itself will begin.

Wow. We are here. We’ve reached other end of the planetary system. Twenty-five years after first wondering if Pluto might someday be explored, we are about to do just that!

This summer’s eighth and final “pre-Pluto” spacecraft and payload Active Check Out (ACO-8) lasted from June through late August, and it was both busy and successful. All spacecraft subsystems—both prime and backup—were checked out. Additionally, we performed our first course-correction since 2010, uploaded the final autonomy system software for the encounter, checked out all seven payload instruments, conducted some final instrument calibrations, and performed our first optical navigation campaign to home in on Pluto using New Horizons’ Long Range Reconnaissance Imager (LORRI).

Those activities went well, and so did many others that we conducted, including more sampling of the heliospheric plasma and dust environment with our PEPSSI, SWAP and Student Dust Counter instruments. The only real anomaly of the entire ACO was a failed startup of a single Alice ultraviolet spectrometer observation. That observation was to study the distribution of interplanetary hydrogen near Neptune’s orbit; it failed because Alice was colder than it ever had been, and onboard software “safed” (or turned off) Alice’s high-voltage power supply when it took too long to get to its set point voltages. In retrospect, this was a blessing in disguise, because it alerted us to loosen up some timing settings for future power-ons when Alice will be as cold or colder as we approach Pluto. Had we not found this out in the ACO, we likely would have discovered it after some missed Pluto observations on approach!

A happy surprise we got from ACO-8 was the subject of a recent news note from New Horizons: A test of the methods we’ll use to search for hazards in the Pluto system on approach detected Pluto’s little moon Hydra. We didn’t think it would be possible to see Hydra until early in 2015, when we are about twice as close as we were in July, but science team members John Spencer and Hal Weaver found Hydra in the July hazard-sequence test! The early detection of Hydra is good news about our ability to detect currently unknown moons and rings.

And in other news, we crossed the orbit of Neptune on Aug. 25. That day just happened to be the 25th anniversary of Voyager 2’s historic close approach to Neptune in 1989—what a cosmic coincidence! To celebrate that and our last planet-orbit crossing before reaching Pluto, NASA held a press conference at its headquarters in in Washington, D.C. Featured speakers were Jim Green, NASA’s director of planetary exploration; Ed Stone, Voyager project scientist; and myself.

After the NASA Headquarters press conference, Dr. Stone presented me, on behalf of the New Horizons project, with a NASA flag that had been flown in Voyager mission control. That flag will now fly in New Horizons mission control, representing Voyager’s passing of the outer solar system exploration baton to New Horizons.

It doesn’t get any more real than that, that we’re almost ready to explore new worlds on the frontier of our solar system! You can watch the press conference, as well as a fascinating panel discussion that followed it, here.


At NASA Headquarters on Aug. 25, Voyager Project Scientist Ed Stone presented me with a NASA flag that flew in Voyager mission control at the Jet Propulsion Laboratory in California; the flag will now fly in New Horizons mission control at the Johns Hopkins Applied Physics Laboratory in Maryland. (Photo by Michael Soluri; permission required for reuse.)

In other mission news, our search for a Kuiper Belt Object to fly by and explore (if NASA approves an extended mission for New Horizons after Pluto) moved into higher gear this summer with a 200-orbit Hubble Space Telescope search. The Hubble search produced spectacular images that contain a bevy of potential targets in the Kuiper Belt that we are now tracking to refine their orbits and to determine our ability to reach them within our fuel supply.

Also, we just completed a week of detailed engineering reviews of every aspects of the past year’s flight, as well as more planning for approach science. And next month, the first encounter approach sequences that serve as the spacecraft flight plan will be built. Each of these sequences runs two weeks. It takes about eight weeks to create, test, review, and certify each one of these to be ready, so we’re beginning in October. By the time December comes, four loads will be in various stages of development at once. And by the spring, seven loads will be in development at once! We’ve planned for this, and staffed up for it, but now the rubber is meeting the road—we’re actually creating and testing the beginning portions of the Pluto encounter!

Finally, before I close this update, I have one more piece of news. On Sept. 11 we reviewed our latest tracking data on New Horizons and determined that the burn this summer was accurate enough that there is no need for any new trajectory correction before at least March, possibly later. So we cancelled the burn opportunity we’d planned for January—it’s simply not necessary. This is a good omen for our hoped-for Kuiper Belt flyby because each burn we can cancel saves a little fuel and makes the Kuiper Belt mission more feasible.

[orin stepanek]

http://pluto.jhuapl.edu/overview/Scienc ... 09_26_2014

Click to view full size image

Science Shorts

Insights from members of the New Horizons Science Team
Rings and Other Solar System Surprises

September 26, 2014

Mark Showalter
New Horizons Co-Investigator

I am known as the "rings guy" on the New Horizons team. I've spent most of my career studying the ring systems of the four giant planets. This unofficial title contains a bit of irony because, to the best of our knowledge, Pluto has no rings. I've received plenty of good-natured jests from my colleagues about being the resident expert on something that doesn't exist. (In my defense, I also observe and study the dynamics of small moons, and Pluto has not disappointed us in that regard.)

Nevertheless, as a rings guy, I had a truly jaw-dropping moment earlier this year when Nature magazine announced the discovery of rings orbiting a 250-kilometer asteroid designated 10199 Chariklo. South American astronomers detected two narrow, dense rings while watching Chariklo pass in front of a star last year.

I can come up with all sorts of reasons why Chariklo's rings should not exist. Asteroids have very weak gravity fields. It is hard for anything to stay on a tidy circular orbit around an object with such a lumpy gravity field. Collisions between ring particles should make the system dissipate. The list goes on...

Nevertheless, the observations are completely unambiguous. The Chariklo rings are real. For me, as a scientist, it has driven home an important message - apparently, I don't understand rings quite as well as I thought I did.

Which brings me back to New Horizons. We are about to fly a spacecraft past Pluto at nearly 14 kilometers per second - about 31,000 miles per hour. A millimeter-sized ring particle could do serious damage, possibly jeopardizing the mission and all of the science data we plan to collect. We have designed alternative trajectories to use if we see something hazardous in our path. I will be part of the team scouring the images as we approach Pluto to look out for any unwelcome surprises and recommend which of those trajectories to use, if necessary.

Overall, however, we remain highly confident the flyby next July will come off as planned. We will be flying through the Pluto system at a place where we expect orbits to be unstable, so the risk of encountering an errant grain of sand is very, very small. So far, nothing we have seen has given us any reason to worry. Still, the message I take away from the Chariklo rings discovery is that a bit of humility is in order. There are still plenty of things out there in the universe that scientists haven't thought of yet...


The discovery of rings around asteroid Chariklo last year - depicted in this artist’s impression - drove home the important message that the solar system is still full of plenty of surprises. (Image credit: ESO/L. Calçada/M. Kornmesser/Nick Risinger)
Mark Showalter, a New Horizons science team co-investigator and senior research scientist at the SETI Institute, is the discoverer of six moons (including Pluto's moons Styx and Kerberos) and three planetary rings. In addition to searching for faint rings and additional small moons, Showalter will be investigating the dynamics, evolution and origin of the Pluto system.

View The Science Shorts Archive >

[orin stepanek]

http://pluto.jhuapl.edu/overview/Scienc ... 10_09_2014

Click to view full size image

October 9, 2014

Will Grundy
New Horizons Co-Investigator

Cool some water below 32° F and it freezes into solid ice; heat it above 212° F and it boils, becoming gaseous steam.

Pluto's surface materials have phase changes too. Nitrogen, methane, and carbon monoxide are detected as solid ices on Pluto's surface, and will be mapped by the instruments aboard New Horizons. But they cannot melt and become liquid, because Pluto's surface pressure is too low. (On Earth, we see the same behavior in frozen carbon dioxide (dry ice), which transforms directly from ice to gas [or “sublimates”] because the pressure at Earth's surface is too low for liquid carbon dioxide to exist.)

Pluto's ices sublimate directly to gas in the same way. Sunshine is weak on Pluto, about a factor of a thousand weaker than on Earth, but it still provides enough heat to cause a little bit of Pluto's surface ices to sublimate into the atmosphere when the Sun shines. Nitrogen is the most volatile of the three known Plutonian ices, followed by carbon monoxide, and then methane. When a mixture of the three ices sublimates, the nitrogen is most readily lost, while the methane tends to linger behind. The surface composition gradually changes as a result of solar-powered sublimation.

Another, more exotic kind of phase change affects Pluto's surface ices. When nitrogen ice is cooled below -396° F, its molecules move around and reorganize themselves from a hexagonal crystal structure into a cubic crystal structure. On warming back up, they revert back to the hexagonal arrangement. Although they are unfamiliar in room temperature materials, this type of phase change between two different solid phases is common among volatile ices. Methane ice has such a transition at -423° F, and carbon monoxide has one at -350° F. Ethane ice, also present on Pluto’s surface, has two phase transitions, one at -298.0° F and one at -298.2° F.

These exotic volatile ices may be the construction materials for what are expected to be correspondingly exotic landforms on Pluto. These will be imaged in exquisite detail by the New Horizons LORRI and MVIC cameras, and our LEISA instrument will reveal what ices make up these landforms.


The mobility of volatile ices that sublimate and condense on Pluto creates an alien and exotic landscape that beckons us from Earth to visit, explore and learn. (Credit: NASA/JHUAPL/W. McKinnon/Nature)
Will Grundy, a New Horizons co-investigator from Lowell Observatory in Flagstaff, Ariz., leads the mission team’s surface composition theme group. His wide-ranging expertise includes icy outer solar system surfaces; telescopic observations of infrared and visible wavelength reflectance; spectroscopy; lab studies of cryogenic ices; phase behavior of ice mixtures; radiative transfer; Kuiper Belt objects; binary and multi-body system orbits; and thermal infrared observations.

View The Science Shorts Archive >

[THX1138]

I am so looking forward to seeing Pluto close up for the first time
The first thing that comes to my mind when i ponder on that which it may find are the 1000 - 1500mph winds on Neptune and Uranus, worlds that were imagined to be just cold and boring

[bystander]

Hubble Finds Potential Kuiper Belt Targets for New Horizons
NASA | STScI | HubbleSite | 2014 Oct 15

[b][i]Kuiper Belt Object 1110113Y Credit: NASA, ESA, SwRI, JHU/APL, and the New Horizons KBO Search Team[/i][/b]

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The Kuiper Belt is a vast disk of icy debris left over from our Sun's formation 4.6 billion years ago. Kuiper Belt objects (KBOs) are a unique class of solar-system body that has never been visited by interplanetary spacecraft. They contain well-preserved clues to the origin of our solar system. NASA's New Horizons probe will fly by Pluto in mid-2015 and then continue across the Kuiper Belt on its way toward interstellar space. The Hubble Space Telescope was used to do a deep sky survey to identify KBOs that the New Horizons spacecraft could potentially visit on its outbound trajectory. The deep sky survey was successful, and Hubble found targetable KBOs for New Horizons.

A Kuiper Belt object (KBO) that is potentially reachable by NASA's Pluto-bound New Horizons probe is visible in multiple exposures taken with the Hubble Space Telescope. Hubble tracked the KBO (named 1110113Y or "PT1") moving against the crowded background field of stars in the constellation Sagittarius. The object is no bigger than 19 to 28 miles across, and it is a deep-freeze relic of what the outer solar system was like 4.6 billion years ago, during the period when the Sun formed. As the KBO orbits the Sun, its position noticeably shifts between exposures taken approximately 10 minutes apart. Following an initial proof of concept of the Hubble pilot observing program in June, the New Horizons team was awarded telescope time by the Space Telescope Science Institute for a wider survey in July. When the search was completed in early September, the team identified this KBO as "definitely reachable" by the New Horizons spacecraft.

[MargaritaMc]

Emily Lakdawalla has written a good blog post about New Horizons' second target.

Finally! New Horizons has a second target

[There is a very nice animated graphic by Alex Parker in the blogpost, but I'm not hotlinking it for copyright reasons. M.Mc]
Orbits of Pluto and PT1, New Horizons' flyby targets

This diagram shows the orbits of the planets (blue), Pluto (white), and New Horizons' Kuiper belt target PT1 (orange), as well as the path of New Horizons (yellow). The diagram also contains dots for other cold classical Kuiper belt objects (orange dots) as well as asteroids and other Kuiper belt objects (white). The Kuiper belt dots are from a model population, based on Canada-France Ecliptic Plane Survey results. A few large Kuiper belt objects are called out in their real locations with large white dots: Eris, Makemake, and Haumea. A labeled still from this animation is also available.

Margarita

[Nitpicker]

Very interesting from Emily L. (thanks M.Mc). I wonder how far PT1 will traverse through our sky, between now and the expected rendezvous in Jan 2019. Probably only 5 or 6 degrees.

[MargaritaMc]

Very interesting from Emily L. (thanks M.Mc). I wonder how far PT1 will traverse through our sky, between now and the expected rendezvous in Jan 2019. Probably only 5 or 6 degrees.

Interesting point. How would one go about finding out?

It's distance from the Sun is 43.4AU, so, as the orbit is nearly circular, that makes its orbital period ~286 years. So, viewed from the Sun (!), it will move ~1.26° per year. But I find that I lack the mathematical skill to work out what difference viewing it from various places on the Earth's orbit, rather than from the Sun, will make.

Probably not much, so your guesstimate of 5 or 6 degrees is probably right.

M

[Nitpicker]

Very interesting from Emily L. (thanks M.Mc). I wonder how far PT1 will traverse through our sky, between now and the expected rendezvous in Jan 2019. Probably only 5 or 6 degrees.

Interesting point. How would one go about finding out?

It's distance from the Sun is 43.4AU, so, as the orbit is nearly circular, that makes its orbital period ~286 years. So, viewed from the Sun (!), it will move ~1.26° per year. But I find that I lack the mathematical skill to work out what difference viewing it from various places on the Earth's orbit, rather than from the Sun, will make.

Probably not much, so your guesstimate of 5 or 6 degrees is probably right.

M

I think it'll be in that range on average, but it will loop back and forth through a retrograde path every year near opposition, so it will really traverse a greater total angular distance.

[orin stepanek]

I thought this site was interesting! Hopefully there will be something new each day!

http://www.boulder.swri.edu/ppod/

[bystander]

New Horizons Set to Wake Up for Pluto Encounter
NASA | JHU-APL | SwRI | 2014 Nov 13

NASA’s New Horizons spacecraft comes out of hibernation for the last time on Dec. 6. Between now and then, while the Pluto-bound probe enjoys three more weeks of electronic slumber, work on Earth is well under way to prepare the spacecraft for a six-month encounter with the dwarf planet that begins in January.

“New Horizons is healthy and cruising quietly through deep space – nearly three billion miles from home – but its rest is nearly over,” says Alice Bowman, New Horizons mission operations manager at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. “It’s time for New Horizons to wake up, get to work, and start making history.” ...

Next month’s wake-up call was preprogrammed into New Horizons’ on-board computer in August, commanding it come out of hibernation at 3 p.m. EST on Dec. 6. About 90 minutes later New Horizons will transmit word to Earth that it’s in “active” mode; those signals, even traveling at light speed, will need four hours and 25 minutes to reach home. Confirmation should reach the mission operations team at APL around 9:30 p.m. EST. At the time New Horizons will be more than 2.9 billion miles from Earth, and just 162 million miles – less than twice the distance between Earth and the sun – from Pluto. ...

[orin stepandk]

The PI's perspective

http://pluto.jhuapl.edu/overview/piPers ... 12_01_2014 Waking Up on Pluto’s Doorstep

December 1, 2014


Our long cruise out from Earth to Pluto is ending.
It’s hard for me to believe, but after almost nine years of flight, we are literally on Pluto’s doorstep, on schedule, in good health, and on course.

In fact, at the end of this week, on Saturday, Dec. 6, New Horizons will awaken from its final segment of hibernation on its historic, 3-billion-plus mile cruise from Earth to Pluto.
(For a countdown clock to wake up, bookmark: http://www.seeplutonow.com/).

After wake-up comes five weeks of “pregame” work, as we prepare and put New Horizons through a few final tests before the encounter. Then, on Jan. 15, we begin what we came here for: the start of Pluto encounter data-collection. I’ll have more to say about early-2015 operations in my next PI Perspective blog.

Here’s Your Chance to Vote on the Wake-Up Graphic

For now, I want to let you know that our wake up mantra, “On Pluto’s Doorstep,” has been beautifully imagined by planetary scientist Alex Parker, a member of the crazy-multitalented New Horizons postdoc team we’ve assembled at the Southwest Research Institute in Boulder, Colorado.

Alex has produced the two “Pluto’s Doorstep” concepts reproduced here. But we can’t decide which we like best.


On Pluto's Doorstep: Option A (click to enlarge)

On Pluto's Doorstep: Option B (click to enlarge)
Since about half our team likes the first image and half our team prefers the second, I thought it would be cool for those of you who follow New Horizons, as well as the general public, help us determine the “People’s Choice” graphic. How? Just cast your vote at http://www.alexharrisonparker.com/plutopoll/#Poll.

But do it soon! Voting on lasts five days, ending at midnight Eastern Time on Friday, Dec. 5, less than a day before New Horizons reports its wake-up to Earth on Saturday night.

I hope you’ll vote, and encourage family, friends and colleagues to vote too! We’ll let you know on wake-up day – Saturday – how the vote turned out.

We’re arriving. Our time is finally near.

Thanks for following us across the expanse of the solar system and into the unknown. Who knows what we’ll find? That’s a big part of the excitement of the exploration of new worlds!

So until I write again, I hope you’ll keep exploring – just as we do!

-Alan Stern


View The PI's Perspective Archive >

[MargaritaMc]

Thank you, Orin. I'll post the exact URL here http://pluto.jhuapl.edu/overview/piPerspective.php to make it easier to jump to it and then go to read the PI archive!