Pluto Spacecraft Planning? New Map Of Neptune’s Icy Triton Could Prepare For 2015 Encounter

Talk about recycling! Twenty-five years after Voyager 2 zinged past Neptune’s moon Triton, scientists have put together a new map of the icy moon’s surface using the old data. The information has special relevance right now because the New Horizons spacecraft is approaching Pluto fast, getting to the dwarf planet in less than a year. And it’s quite possible that Pluto and Triton will look similar.

Triton has an exciting history. Scientists believed it used to be a lone wanderer until Neptune captured it, causing tidal heating that in turn created fractures, volcanoes and other features on the surface. While Triton and Pluto aren’t twins — this certainly didn’t happen to Pluto — Pluto also has frozen volatiles on its surface such as carbon monoxide, methane and nitrogen.

What you see in the map is a slightly enhanced version of Triton’s natural colors, bearing in mind that Voyager’s sensors are a little different from the human eye. Voyager 2 only did a brief flyby, so only about half the planet has been imaged. Nonetheless, the encounter was an exciting time for Paul Schenk, a planetary scientist at the Lunar and Planetary Institute in Houston. He led the creation of the new Triton map, and wrote about the experience of Voyager 2 in a blog post.

“Triton is a near twin of Pluto,” wrote Schenk. “Triton and Pluto are both slightly smaller than Earth’s Moon, have very thin nitrogen atmospheres, frozen ices on the surface (carbon monoxide, carbon dioxide, methane and nitrogen), and similar bulk composition (a mixture of ices, including water ice, and rock.  Triton however was captured by Neptune long time ago and has been wracked by intense heating ever since.  This has remade its surface into a tortured landscape of overturned layers, volcanism, and erupting geysers.”

He also added speculation about what will be seen at Pluto. Will it be a dead planet, or will geology still be affecting its surface? How close will Triton be to Pluto, particularly regarding its volcanoes? Only a year until we know for sure.

Sources: NASA, Lunar and Planetary Institute, Paul Schenk

Watch Pluto and Charon Engage in Their Orbital Dance

Now here’s something I guarantee you’ve never seen before: a video of the dwarf planet Pluto and its largest moon Charon showing the two distinctly separate worlds actually in motion around each other! Captured by the steadily-approaching New Horizons spacecraft from July 19–24, the 12 images that comprise this animation were acquired with the Long Range Reconnaissance Imager (LORRI) instrument from distances of 267 million to 262 million miles (429 million to 422 million km) and show nearly a full orbital rotation. Absolutely beautiful!

For a close-up video of the two worlds in motion, click below:

Pluto and Charon rotation movie from New Horizons (enlarged view)
Pluto and Charon rotation movie from New Horizons (enlarged view)

Pluto and Charon are seen circling a central gravitational point known as the barycenter, which accounts for the wobbling motion. Since Charon is 1/12th the mass of Pluto the center of mass between the two actually lies a bit outside Pluto’s radius, making their little gravitational “dance” readily apparent.

(The same effect happens with the Earth and Moon too, but since the barycenter lies 1,700 km below Earth’s surface it’s not nearly as obvious.)

“The image sequence showing Charon revolving around Pluto set a record for close range imaging of Pluto—they were taken from 10 times closer to the planet than the Earth is,” said New Horizons mission Principal Investigator Alan Stern, of the Southwest Research Institute. “But we’ll smash that record again and again, starting in January, as approach operations begin.”

Fastest Spacecraft
Artist concept of the New Horizons spacecraft. Credit: NASA

Launched January 19, 2006, New Horizons is now in the final year of its journey to the Pluto system. On August 25 it will pass the orbit of Neptune – which, coincidentally, is 25 years to the day after Voyager 2’s closest approach – and then it’s on to Pluto and Charon, which New Horizons will become the first spacecraft to fly by on July 14, 2015, at distances of 10,000 and 27,000 km respectively. Find out where New Horizons is right now here.

Source: New Horizons

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

Here’s Your Chance To Fund A Universe Today Project On The Pluto Planethood Debate

New Horizons

This fall, Universe Today plans to get in-depth into the Pluto planethood debate. I (Elizabeth Howell) just launched a crowdfunding project on a new platform called Beacon that will allow me to fly down to Washington, D.C. for several days to interview Pluto scientists.

Should the project be funded, a few fun things are going to happen. Here, Universe Today readers will get a series of articles into the Pluto planethood debate. We’ll examine the controversial International Astronomical Union vote and why certain scientists still don’t believe Pluto is a dwarf planet today.

The question has special relevance today because NASA’s New Horizons spacecraft is on a journey to Pluto, and is less than a year from getting there. Examining Pluto will give scientists a window into how the solar system formed, which in turn gives us clues as to how the Earth came to be. We’ll have some stuff about the science as well; stay tuned for the details!

You’ll also get the chance to support astronomy education and outreach. I’m pleased to announce that CosmoQuest will be a partner on the project, receiving 15% of all proceeds for the project. If you contribute $250, $500 or $1,000, they will receive an additional 15% of your money. Contributors at this level will have their name mentioned in at least two of a series of six podcasts I will do for CosmoQuest’s 365 Days of Astronomy. There are other fun perks, too, so check out the Beacon page for more.

CosmoQuest-Logo-Full-sm3

As a freelance journalist, my challenge with doing travel stories is I have to pay my own way. Beacon solves that problem. It will allow me to spend a few days in person with scientists, gathering pictures and videos and podcasts, instead of relying on the phone interviews I usually conduct.

After paying contributions to CosmoQuest and to Beacon, every single cent remaining will be for travel expenses only. The money will give me a flight to Washington, D.C., a few nights in a reasonable hotel, and a car rental. I promise you that I’m extremely frugal — ask my mortgage broker — and I will spend every dollar of your contributions wisely. Additional money after $2,400 will allow me to draw a salary for the days I am there. If a substantial amount of extra money is raised, I’ll consider a second trip to D.C.

A NASA "poster" marking the one year to Pluto encounter by New Horizons. Credit: NASA
A NASA “poster” marking the one year to Pluto encounter by New Horizons. Credit: NASA

I’m not one to brag about my experience, but I will say that I’ve been proudly writing about space for a decade for many publications (including Universe Today). I’m one of the few journalists in Canada to focus on space virtually full-time. And I have covered some fun stories, such as three shuttle launches (2009-10), Chris Hadfield’s last mission (2012-13) and participating in a simulated Mars mission in Utah (early 2014). I see space as a field where I can always learn more, and this will be a great chance to share what I learn about Pluto with you.

Any questions? Feel free to get in touch with me at contact AT elizabethhowell DOT ca or to leave comments below. I likely won’t be able to respond until tomorrow as this launch coincidentally falls on a planned vacation day for me, but I promise that for the rest of the campaign I’ll answer your queries as fast as I can.

How to See Pluto at Opposition as New Horizons Crosses the One Year Out Mark

Are you ready for 2015? On July 14th, 2015 — just a little over a year from now — NASA’s New Horizons spacecraft with perform its historic flyby of Pluto and its retinue of moons. Flying just 10,000 kilometres from the surface of Pluto — just 2.5% the distance from Earth to the Moon on closest approach — New Horizons is expected to revolutionize our understanding of these distant worlds.

And whether you see Pluto as a much maligned planetary member of the solar system, an archetypal Plutoid, or the “King of the Kuiper Belt,” you can spy this denizen of the outer solar system using a decent sized backyard telescope and a little patience.

New Horizon in the clean room having its plutonium-fueled MMRTG installed. (Credit: NASA).
New Horizons in the clean room having its plutonium-fueled MMRTG installed. (Credit: NASA).

Pluto reaches opposition for 2014 later this week on Friday, July 4th at 3:00 Universal Time (UT), or 11:00 PM EDT on July 3rd. This means that Pluto will rise to the east as the Sun sits opposite to it in the west at sunset and transits the local meridian high to the south at local midnight. This is typically the point of closest approach to Earth for any outer solar system object and the time it is brightest.

Dusk July 4th Credit
The location of Pluto at dusk on July 4th, the night of opposition. Credit: Stellarium.

But even under the best of circumstances, finding Pluto isn’t easy. Pluto never shows a resolvable disk in even the largest backyard telescope, and instead, always appears like a tiny star-like point. When opposition occurs near perihelion — as it last did in 1989 — Pluto can reach a maximum “brilliancy” of magnitude +13.6. However, Pluto has an extremely elliptical orbit ranging from 30 to 49 Astronomical Units (A.U.s) from the Sun. In 2014, Pluto has dropped below +14th magnitude at opposition as it heads back out towards aphelion one century from now in 2114.

Pluto from July-Dec
The path of Pluto from July to December 2014. Created using Starry Night Education Software.

Another factor that makes finding Pluto challenging this decade is the fact that it’s crossing through the star-rich plane of the galaxy in the direction of the constellation Sagittarius until 2023. A good finder chart and accurate pointing is essential to identifying Pluto as it moves 1’ 30” a day against the starry background from one night to the next.

In fact, scouring this star-cluttered field is just one of the challenges faced by the New Horizons team as they hunt for a potential target for the spacecraft post-Pluto encounter. But this has also meant that Pluto has crossed some pretty photogenic regions of the sky, traversing dark Bok globules and skirting near star clusters.

Pluto (marked) imaged by Jim Hendrickson on the morning of June 29th.
Pluto (marked) imaged by Jim Hendrickson @SkyscraperJim on the morning of June 28th.

You can use this fact to your advantage, as nearby bright stars make great “guideposts” to aid in your Pluto-quest. Pluto passes less than 30” from the +7th magnitude pair BB Sagittarii on July 7th and 8th and less than 3’ from the +5.2 magnitude star 25 Sagittarii on July 21st… this could also make for an interesting animation sequence.

Though Pluto has been reliably spotted in telescopes as small as 6” in diameter, you’ll most likely need a scope 10” or larger to spot it. We’ve managed to catch Pluto from the Flandrau observatory situated in downtown Tucson using its venerable 14” reflector.

June 28th-August 8th (inverted)
The path of Pluto June 28th-August 8th. (click here for an inverted white background view). Created using Starry Night Education Software.

Pluto was discovered by Clyde Tombaugh from the Lowell Observatory in 1930 while it was crossing the constellation Gemini. It’s sobering to think that it has only worked its way over to Sagittarius in the intervening 84 years. It was also relatively high in the northern hemisphere sky and headed towards perihelion decades later during discovery. 2014 finds Pluto at a southern declination of around -20 degrees, favoring the southern hemisphere. Had circumstances been reversed, or Pluto had been near aphelion, it could have easily escaped detection in the 20th century.

We’re also fortunate that Pluto is currently relatively close to the ecliptic plane, crossing it on October 24th, 2018. Its orbit is inclined 17 degrees relative to the ecliptic and had it been high above or below the plane of the solar system, sending a spacecraft to it in 2015 might have been out of the question due to fuel constraints.

The current location of New Horizons. (Credit: NASA/JPL).
The current location of New Horizons. (Credit: NASA/JPL).

And speaking of spacecraft, New Horizons now sits less than one degree from Pluto as seen from our Earthly vantage point. And although you won’t be able to spy this Earthly ambassador with a telescope, you can wave in its general direction on July 11th and 12th, using the nearby waxing gibbous Moon as a guide:

The Moon, Pluto and New Horizons as seen on July 11th. (Created Using Starry Night Education Software).
The Moon, Pluto and New Horizons as seen on July 11th. (Created Using Starry Night Education Software).

All eyes will be on Pluto and New Horizons in the coming year, as it heads towards a date with destiny… and we’ll bet that the “is Pluto a planet?” debate will rear its head once more as we get a good look at these far-flung worlds.

And hey, if nothing else, us science writers will at last have some decent pics of Pluto to illustrate articles with, as opposed to the same half-dozen blurry images and artist’s renditions…

Where To Go After Pluto? Hubble Seeks The Next Target For New Horizons

It’s going to be a really busy summer for the New Horizons team. While they’re checking out the newly awakened spacecraft to make sure it’s working properly for its close encounter with Pluto next year, NASA is already thinking about where to put it next: possibly towards a Kuiper Belt Object!

So now the Hubble Space Telescope (in Earth orbit) is scoping out icy objects beyond Pluto. Luckily for us, one of the team members — Alex Parker, a planetary astronomer at the University of California, Berkeley, provided an entertaining livetweet of the process — even through a power failure.

There’s far more to Parker’s tweets than we are indicating here; his Twitter feed also has details about the collaborators, for example, so be sure to read through the entire exchange from yesterday. The survey is led by the Southwest Research Institute’s John Spencer.

What astronomers are doing now is a “pilot observation” where the space telescope looks at a spot in the constellation Sagittarius. Controllers will try to turn the telescope at the same rate as what a KBO would be orbiting around the sun. If the method works, stars will look like streaks and the KBOs will look like “pinpoint objects”, NASA stated.

A view of the Hubble Space Telescope from inside space shuttle Atlantis on mission STS-125 in 2009. Credit: NASA
A view of the Hubble Space Telescope from inside space shuttle Atlantis on mission STS-125 in 2009. Credit: NASA

“If the test observation identifies at least two KBOs of a specified brightness it will demonstrate statistically that Hubble has a chance of finding an appropriate KBO for New Horizons to visit. At that point, an additional allotment of observing time will continue the search across a field of view roughly the angular size of the full moon,” NASA said in a press release.

The reason for this step is Hubble is a high-profile telescope, receiving a lot of requests for observing time around the world. The agency wants to ensure that the telescope is being used for the best scientific return possible. NASA also noted the search might be difficult.

“Though Hubble is powerful enough to see galaxies near the horizon of the universe, finding a KBO is a challenging needle-in-haystack search. A typical KBO along the New Horizons trajectory may be no larger than Manhattan Island and as black as charcoal,” NASA stated.

This isn’t the first time the telescope has done a pinch-hit for Plutonian science. Four new moons have been found around Pluto, a discovery that involved Hubble time. The telescope has also looked for dust rings near the dwarf planet (to do a risk analysis for New Horizons’ approach) and done a map of the surface, to help controllers figure out where to target New Horizons.

New Horizons Prepares to Zoom to Pluto

Artist impression of the New Horizons spacecraft sweeping past Pluto. Image credit: JHUAPL/SwRI. Click to enlarge.

If all goes well, the first mission to the farthest known planet in our Solar System will launch in early 2006, and give us our first detailed views of Pluto, its moon Charon, and the Kuiper Belt Region, while completing NASA’s reconnaissance of all the planets in our Solar System.

“We’re going to a planet that we’ve never been to before,” said Dr. Alan Stern, Principal Investigator for the New Horizons mission to Pluto. “This is like something out of a NASA storybook, like in the 60’s and 70’s with all the new missions that were happening then. But this is exploration for a new century; it’s something bold and different. Being the first mission to the last planet really ‘revs’ me. There’s something special about going to a new frontier, about

Pluto is so far away (5 billion km or 3.1 billion miles when New Horizons reaches it) that no telescope, not even the Hubble Space Telescope, has been able to provide a good image of the planet, and so Pluto is a real mystery world. The existence of Pluto has only been known for 75 years, and the debate continues about its classification as a planet, although most planetary scientists classify it in the new class of planets called Ice Dwarfs. Pluto is a large, ice-rock world, born in the Kuiper Belt area of our solar system. Its moon, Charon, is large enough that some astronomers refer to the two as a binary planet. Pluto undergoes seasonal change and has an elongated and enormous 248-year orbit which causes the planet’s atmosphere to cyclically dissipate and freeze out, but later be replenished when the planet returns closer to the sun.

New Horizons will provide the first close-up look at Pluto and the surrounding region. The grand piano-sized spacecraft will map and analyze the surface of Pluto and Charon, study Pluto’s escaping atmosphere, look for an atmosphere around Charon, and perform similar explorations of one or more Kuiper Belt Objects.

The spacecraft, built at the Johns Hopkins Applied Physics Laboratory, is currently being flight tested at the Goddard Space Flight Center. Dr. Stern has been planning a mission to Pluto for quite some time, surviving through the various on-again, off-again potential missions to the outer solar system.

“I’m feeling very good about the mission,” he said in an interview from his office at the Southwest Research Institute in Boulder, Colorado. “I’ve been working on this project for about 15 years, and the first 10 years we couldn’t even get it out of the starting blocks. Now we’ve not only managed to get it funded, but we have built it and we are really looking forward to flying the mission soon if all continues to go well.”

Of the hurdles remaining to be cleared before launch, one looms rather large. New Horizons’ systems are powered by a Radioisotope Thermoelectric Generator (RTG), where heat released from the decay of radioactive materials is converted into energy. This type of power system is essential for a mission going far from the Sun like New Horizons where solar power is not an option, but it has to be approved by both NASA and the White House. The 45-day public comment period ended in April 2005, so the project now awaits final, official approval. Meanwhile, the New Horizons mission teams prepare for launch.

“We still have a lot of work in front of us,” Stern said. “All this summer we’re testing and checking out the spacecraft and the components, getting all the bugs out, and making sure its launch ready, and flight ready. That will take us through September and in October we hope to bring the spacecraft to the Cape.”

The month-long launch window for New Horizons opens on January 11, 2006.

New Horizons will be the fastest spacecraft ever launched. The launch vehicle combines an Atlas V first stage, a Centaur second stage, and a STAR 48B solid rocket third stage.

“We built the smallest spacecraft we could get away with that has all the things it needs: power, communication, computers, science equipment and redundancy of all systems, and put it on the biggest possible launch vehicle,” said Stern. “That combination is ferocious in terms of the speed we reach in deep space.”

At best speed, the spacecraft will be traveling at 50 km/second (36 miles/second), or the equivalent of Mach 85.

Stern compared the Atlas rocket to other launch vehicles. “The Saturn V took the Apollo astronauts to the moon in 3 days,” he said. “Our rocket will take New Horizons past the moon in 9 hours. It took Cassini 3 years to get to Jupiter, but New Horizons will pass Jupiter in just 13 months.”

Still, it will take 9 years and 5 months to cross our huge Solar System. A gravity assist from Jupiter is essential in maintaining the 2015 arrival date. Not being able to get off the ground early in the launch window would have big consequences later on.

“We launch in January of 2006 and arrive at Pluto in July of 2015, best case scenario,” said Stern. “If we don’t launch early in the launch window, the arrival date slips because Jupiter won’t be in as good a position to give us a good gravity assist.”

New Horizons has 18 days to launch in January 2006 to attain a 2015 arrival. After that, Jupiter’s position moves so that for every 4 or 5 days delay in launch means arriving at Pluto year later. By February 14 the window closes for a 2020 arrival. New Horizons can try to launch again in early 2007, but then the best case arrival year is 2019.

New Horizons will be carrying seven science instruments:

  • Ralph: The main imager with both visible and infrared capabilities that will provide color, composition and thermal maps of Pluto, Charon, and Kuiper Belt Objects.
  • Alice: An ultraviolet spectrometer capable of analyzing Pluto’s atmospheric structure and composition.
  • REX: The Radio Science Experiment that measures atmospheric composition and surface temperature with a passive radiometer. REX also measures the masses of objects New Horizons flies by.
  • LORRI: The Long Range Reconnaissance Imager has a telescopic camera that will map Pluto?s far side and provide geologic data.
  • PEPSSI: The Pluto Energetic Particle Spectrometer Science Investigation that will measure the composition and density of the ions escaping from Pluto’s atmosphere.
  • SWAP: Solar Wind Around Pluto, which will measure the escape rate of Pluto?s atmosphere and determine how the solar wind affects Pluto.
  • SDC: The Student Dust Counter will measure the amount of space dust the spacecraft encounters on the voyage. This instrument was designed and will be operated by students at the University of Colorado in Boulder.

Stern says the first part of the flight will keep the mission teams busy, as they need to check out the entire spacecraft, and execute the Jupiter fly-by at 13 months.

“The middle years will be long and probably — and hopefully — pretty boring,” he said, but will include yearly spacecraft and instrument checkouts, trajectory corrections, instrument calibrations and rehearsals the main mission. During the last three years of the interplanetary cruise mission teams will be writing, testing and uploading the highly detailed command script for the Pluto/Charon encounter, and the mission begins in earnest approximately a year before the spacecraft arrives at Pluto, as it begins to photograph the region.

A mission to Pluto has been a long time coming, and is popular with a wide variety of people. Children seem to have an affinity for the planet with the cartoon character name, while the National Academy of Sciences ranked a mission to Pluto as the highest priority for this decade. In 2002, when it looked as though NASA would have to scrap a mission to Pluto for budgetary reasons, the Planetary Society, among others, lobbied strongly to Congress to keep the mission alive.

Stern said the mission’s website received over a million hits the first month it was active, and the hit rate hasn’t diminished. Stern writes a monthly column on the website, http://pluto.jhuapl.edu , where you can learn more details about the mission and sign-up to have your name sent to Pluto along with the spacecraft.

While Stern is understandably excited about this mission, he says that any chance to explore is a great opportunity.

“Exploration always opens our eyes,” he said. “No one expected to find river valleys on Mars, or a volcano on Io, or rivers on Titan. What do I think we’ll find at Pluto-Charon? I think we’ll find something wonderful, and we expect to be surprised.”