Beyond Pluto with New Horizons

Ron Hobbs has been a NASA JPL Solar System Ambassador almost since that program started just over 20 years ago. What began as an effort to recruit volunteers to help keep people informed about the Galileo mission to Jupiter soon expanded to include most other JPL missions.

“Education and public outreach is very important to NASA,” Hobbs explained. “They’re spending Americans’ money to go out and explore the universe, and they want to make sure that they get the information out to everyone who’s interested in it.”

New Horizons

There’s a lot of interest. Hobbs and I talked recently about New Horizons, which did a historic fly-by of Pluto in 2016 and is now napping while whizzing through space for a New Year’s date with the romantically named 2014 MU69. This object, discovered in 2014 using the Hubble Space Telescope specifically to find a potential place for New Horizons to visit after Pluto, is in a relatively undisturbed part of the Kuiper Belt. Observations made of MU69 suggest that it is either oblong or a binary object, perhaps a contact binary. Recent research has suggested that most early planetesimals were binaries.

“It is very likely that it is one of these primordial planetesimals,” Hobbs said. “So in some senses the exploration of MU69 may be more important than the exploration of Pluto. And that’s saying a lot.”
Hobbs shared a couple of favorite bits of information about New Horizons. For one, the spacecraft is carrying human remains.

“Clyde Tombaugh, the discoverer of Pluto, will become the first human being to have their remains interred in interstellar space,” Hobbs noted.

New Horizons Principal Investigator Alan Stern presents a
plaque to Venetia Burney Phair in December 2006,
commemorating the name “Venetia” for the New Horizons Student
Dust Counter. Phair passed away in 2009. Photo: NASA

One of the instruments aboard New Horizons is the The Venetia Burney Student Dust Counter, named after the English schoolgirl who suggested the name for Pluto way back in 1930. The instrument was built and managed by students at the University of Colorado.

“It is the first student built instrument on a major NASA probe, ever,” Hobbs said. It’s just one example about how the mission is becoming a world-wide effort. Hobbs marvels that we are all space explorers.

Scientists are searching for another possible target for New Horizons after it does its flyby of MU69. Hobbs said the craft has limited fuel, so it’s unclear how much more it can maneuver.

Listen to the podcast to learn more about New Horizons and how ordinary citizens are participating in science.

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Hobbs also recommends a recent NASA “Gravity Assist” podcast featuring New Horizons principal investigator Alan Stern.

Threading the needle with Cassini at Saturn

The hugely successful Cassini mission to Saturn will come to a fiery end in September, and you can hardly blame NASA for going a little Star Trek on us.

Ron Hobbs. Photo: Greg Scheiderer.

“We’re going somewhere where no spacecraft has ever gone before, into this region between the glorious rings of Saturn and the cloud tops of the planet,” said Ron Hobbs, a NASA Solar System Ambassador, at this month’s meeting of the Seattle Astronomical Society. After 22 orbits through the eye of that needle—a 2,500-kilometer-wide gap—they’ll splat Cassini into the planet and burn it up.

“Now that we’ve discovered that there’s at least one moon, and maybe several, that could have the conditions for life, it’s very important to not leave a derelict spacecraft orbiting around Saturn,” Hobbs noted. “One of the important things at the end of the solstice mission will be to dispose of the spacecraft.”

The second extended mission of Cassini was named solstice because it is almost the beginning of summer in Saturn’s northern hemisphere.

Let’s do science

Before they crash Cassini, they figured there was some time to do some great science in that place where no spacecraft has ever gone. Most importantly, they will get a better picture of the internal structure of Saturn and examine its ionosphere, inner radiation belts, and auroral region.

“This would have been worth sending a spacecraft to Saturn for just that measurement,” Hobbs said, noting that it is essentially what Juno is doing at Jupiter. They’ll also check out the particles of Saturn’s D ring at close range, and be able to better gauge the mass of the ring system, which will help pin down its age.

“I can’t wait for the pictures,” Hobbs added. “The pictures that come out of this mission are just going to be spectacular.”

Shooting the gap

Hobbs said NASA has been using interactions between Cassini and Saturn’s moon Titan to nudge the spacecraft’s orbit to where they want it to be.

“Titan is really the only object in Saturn orbit that has enough mass to allow it to do gravitational assists and re-direct its orbit,” he said. “That allows [Cassini] to change its orbit and change the plane of its orbit.”

This graphic shows the closest approaches, or periapses, of
Cassini’s final two orbital phases.The ring-grazing orbits
are shown in gray; grand finale orbits are shown in blue.
The orange line shows the spacecraft’s final plunge into
Saturn. Credit: NASA / Jet Propulsion Laboratory – Caltech

In late November a brush with Titan dropped Cassini’s perichron—the point closest to Saturn in its orbit around the planet—down to just outside the F ring. In April, another Titan flyby will drop that perichron down to between the D ring and Saturn’s cloud tops.

“That’s when it’s going to get really exciting,” Hobbs said. Cassini will do 22 “grand finale” orbits through the eye of this needle, each lasting six days, collecting science data until one final encounter with Titan puts the spacecraft on a trajectory to splat into the planet on September 15.

It’s amazing how much planning and politics went into all of this. Hobbs said the actual trajectories of the orbits for this grand finale were determined a little over three years ago. Ever since then there’s been a spirited discussion between scientists, engineers, and mission leaders about what science to do to get as much data as possible out of the final mission. That determination was just completed last month.

“The spacecraft drivers are now writing the code for these orbits,” Hobbs said. That will tell Cassini where to go and where to point its instruments to make the observations as planned.

A good ride

Hobbs noted that Cassini was launched in October 1997, and so will end its mission just shy of twenty years in space.

“Without a doubt it has been one of the most successful and audacious missions NASA and the international community have operated,” he said. “This is going to be one of the highlights of space exploration in the last couple of decades.”

Juno set to answer big questions at Jupiter

Almost five years after it was launched, NASA’s Juno spacecraft will arrive at Jupiter on July 4, and Ron Hobbs is pretty excited about it. Hobbs, a Seattle-based NASA Solar System Ambassador, recently learned the inside scoop about the Juno mission during a teleconference with the mission’s principal investigator, Dr. Scott Bolton, who is the associate vice president for the space science and engineering division at the Southwest Research Institute.

Artist concept of Juno at Jupiter. Image: NASA/JPL.

“The Juno mission is about reverse-engineering the recipe of the soup that is our solar system,” Hobbs said. He noted that the Sun contains the vast majority of the mass in the solar system. After the Sun was born, Jupiter formed next, and it weighs two-and-a-half times more than everything else—the rest of the planets, comets, asteroids, the works.

Juno has four main scientific objectives, according to Hobbs: figuring out what’s at Jupiter’s core, studying the planet’s atmosphere and magnetosphere, and figuring out where its water came from.

Water

NASA/JPL Solar System Ambassador
Ron Hobbs. Photo: Greg Scheiderer.

“The present theories about the solar system origin and evolution do not explain how Jupiter was enriched in heavy elements,” Hobbs said, noting that, in astronomical terms, anything above hydrogen or helium is considered heavy. “The key to understanding how the giant planets form, and then how the rest of the planets form, and how other planetary systems form is really the key to how those heavy elements got into Jupiter.”

Hobbs noted that the Galileo mission in 1995 sent a probe into Jupiter in search of water but didn’t find much. Scientists speculate they may have just gotten unlucky, and hit a sort of Sahara Desert area of Jupiter. Juno will avoid that problem by using antennas to measure microwave radiation from Jupiter; we’ll be able to tell how much water is there by how much energy is absorbed. It’s a lot less costly than probes and we’ll be able to get measurements from all over Jupiter and to greater depths.

Atmosphere

Juno will answer questions about Jupiter’s most visible features as it studies the Jovian atmosphere.

“It’s going to be able to get atmospheric composition, temperature, cloud opacity and dynamics to depths greater than 100 bars at all latitudes,” Hobbs said. “We’re really going to start to understand what those belts and zones that we see here from Earth are composed of.”

Magnetosphere

“Jupiter has a huge magnetosphere, and there’s still some uncertainty about how it formed,” Hobbs noted. Like Earth’s Van Allen Belts, there’s a lot of radiation trapped there.

“They’re so intense at Jupiter that any spacecraft going into them is in danger of having its electronics fried,” Hobbs said. “Humans, living things, would never survive; the radiation levels are just incredible.”

Juno will make polar orbits around Jupiter. Previous missions have taken equatorial orbits. Hobbs said the polar orbit will help the craft avoid intense radiation, and will create some great imaging opportunities.

“We know that Jupiter has incredible aurorae, but they’ve never been seen up close,” Hobbs said. “In polar orbit Juno is going to be able to get close-up views.”

Gravity science

Jupiter is known as a “gas giant,” but scientists believe it has a metallic core of really heavy elements: iron, nickel, silicon and the like. They don’t know for sure.

“The gravity science that Juno will do will answer that question, will tell us the interior structure,” Hobbs explained.

Juno will study the interior of Jupiter by mapping both its gravitational and magnetic fields. Hobbs said scientists expect to find metallic hydrogen.

“We believe that at some point down in this giant body hydrogen is under so much pressure that it becomes a metal,” Hobbs said. “We believe there’s a whole ocean, if you will, or mantle of metallic hydrogen.”

About Juno

Hobbs said Juno is the second mission of NASA’s New Frontiers program. New Horizons, which flew past Pluto last summer, was the first.

“New Frontiers is a follow-on to the Discovery program, where NASA basically funds investigator-led missions,” Hobbs said. “The Discovery missions are all low-cost missions, largely to the inner solar system, but there were enough targets of opportunity that they saw the need for an expanded program.”

Juno will make 33 orbits of Jupiter, each taking about two weeks. It will get within 5,000 kilometers of its cloud tops. The electronics are protected from radiation inside a 200-kilogram titanium vault. The craft is powered by huge solar panels that are about 80 feet across as the craft spins. It will be the furthest we’ve sent a solar-powered spacecraft.

Juno Cam

This image of Earth was taken during the close flyby 

of NASA’s Juno spacecraft on October 9, 2013. 

The coastline of Argentina is at the upper left, 

and clouds cover much of Antarctica at bottom. 

Image credit: NASA/JPL-Caltech/MSSS

Juno will be spinning, which makes photography a challenge. But we love our space images, and Hobbs said the craft carries the Juno Cam to grab photographs, though it’s not considered to be an official scientific instrument. Still, it took some great images of Earth during a gravity-assist fly-by in 2013. Hobbs said Juno Cam is naturally outside the titanium vault, which will leave it exposed to radiation.

“I’m looking forward to getting those pictures taken and down here on Earth early on in the mission, because I have a feeling it’s going to be one of the first things that gets fried,” he said.
Hobbs is looking forward to getting data from Juno starting next month.

“It’s a cool mission and it’s answering some really fundamental questions,” he said. “We’re going to learn a lot about our place in the universe once again.”

Celebrating 10 years at Saturn

The Cassini spacecraft went into orbit around Saturn ten years ago, on July 1, 2004 in universal time. Ron Hobbs, a solar system ambassador of the NASA Jet Propulsion Lab, says some of the mission’s most exciting science has occurred quite recently.

Hobbs spoke at the most recent meeting of the Seattle Astronomical Society about Cassini’s decade at Saturn, and notes that recent measurements of the gravitational field of the moon Enceladus have yielded some interesting findings.

“We are very confident that there is body of liquid water at the south pole that extends at least to 50 degrees south latitude on Enceladus,” Hobbs says. “There’s a body of water that’s in contact with rock. We know that some of the ice particles that get shot out into the E-ring have salt and organics in them. This has become on a very short list of places in our own solar system where we might find life.”

Mars and Jupiter’s moon Europa are two others on what Hobbs calls the “astrobiological short list.” Many scientists believe that life on Earth may have originated in hydrothermal ocean vents—a safe haven during the heavy bombardment era—and so it’s reasonable to suspect that life might thrive in similar environments elsewhere in the solar system.

Hobbs calls Cassini “the largest, most complex, and capable spacecraft ever built” and notes that we may owe its existence to persistent Europeans. There was some talk in the mid-’90s that Congress would scrap the mission before it got off the ground because of budget concerns. But the Europeans had already built the Huygens probe that hitched a ride on Cassini in order to do a study of the atmosphere of the moon Titan. Hobbs says word is that protests about the proposed cuts made it all the way to the vice president.

“The fact that we have Cassini, as far as I’m concerned, is in large part due to the fact that the Europeans had the guts to talk to the U.S. government and say, ‘You don’t renege on your promises,'” Hobbs says.

Like the Mars rover missions, Cassini has far exceeded the time allotted for its original scientific mission.

“The plan for Cassini when it arrived in July of 2004 was to study Saturn for four years,” Hobbs notes. “Cassini is still one of the healthiest spacecraft we have anywhere in the solar system. All of its instruments are working great, it’s got fuel.” Nonetheless, Hobbs says he occasionally hears talk that Congress again is considering pulling the plug on the mission. He says that would be a bad idea, as we still have a lot to learn.

The NASA video below gives a preview of the work they’re planning for Cassini over the next four years.

Funding Opportunity a "no brainer"

As Congress debates NASA’s budget there’s been some talk about pulling the plug on the Mars Exploration Rover Opportunity, which has been exploring the Red Planet for more than 10 years. Seattle-based Solar System Ambassador Ron Hobbs says that would be pure folly.

“We get so much bang for such a little buck for planetary sciences,” Hobbs says. He notes that Opportunity is a mere 600 meters away from what he calls “the promised land of clay” in the Endeavor crater—stratified clay that will give scientists a wealth of information about the geological history of Mars. It’s also a beautiful spot.

“For the photography alone it should be worth going, for the science alone it should be worth going,” Hobbs says. “Put the two together, to me, it’s a no-brainer” to keep Opportunity operating.

Opportunity took this self portrait in late March as wind storms
cleaned its solar panels. Photo: NASA / JPL-Caltech / Cornell / ASU

Hobbs notes that it’s just such a geological feature that caused scientists to pick Gale Crater as the destination for the Curiosity rover, which should reach its primary target later this year. Hobbs adds that, to some degree, the existence of Curiosity is a threat to Opportunity.

“If they shut down Opportunity it will be a victim of its own success and the success of all the things that JPL does,” he says.

Hobbs says Opportunity also may be a bit of a victim of over-delivering on its promise. The mission was originally slated to last 90 days, in large part because planners—a superstitious lot—didn’t want to jinx the mission by predicting a long life. Hobbs notes that we build robust spacecraft in America, but there’s a lot of uncertainty out in space.

“You’re going into an extreme environment, and who knows what could happen? You could get hit by a meteorite and be vaporized. Mission over right there,” he says. “You could not land, which is actually the biggest risk and why they sent two” rovers to land on Mars in 2004: Opportunity and Spirit, which worked until 2010. The longest anyone dared suggest the twin rovers would last is a year.

“I think everybody assumed that the first Martian winter would kill them,” Hobbs says. “They certainly thought that a dust storm would kill them. It’s blowing everybody away at this point that Opportunity is still around 10 years later. Nobody expected this.”

In fact, he says anyone who had suggested a rover would last for a decade would have been drummed out of the scientific community.

“They would have been dismissed as completely wacko!” he laughs. “Yet, here we are!”

In fact, Opportunity is working better than it has in several years. A recent wind storm cleaned off its solar panels, and they’re generating higher power than they have in a while.

Hobbs has a hunch that Opportunity ultimately will be funded. It’s continuing work on real science and the public’s love for the rover would likely generate an outcry were the plug pulled.
Stay tuned!

Enceladus and the platinum age of planetary exploration

Ours is a great time to be alive if you have an interest in learning about other worlds, at least according to Ron Hobbs, a NASA Solar System Ambassador and museum educator and public programs assistant at Seattle’s Museum of Flight.

“For most of us the golden age of planetary exploration was the ‘70s and early ‘80s,” Hobbs said. “The time of the Apollo Moon missions—particularly those that did a lot of science—the Viking missions to Mars, and of course Voyager.”

At least four distinct plumes of water ice spew out from the
south polar region of Saturn's moon Enceladus in this dramatically
illuminated image, shot on Christmas Day 2009 by Cassini.
Light reflected off Saturn is illuminating the surface of the moon
while the Sun, almost directly behind Enceladus, is backlighting
the plumes. Photo: NASA/JPL/Space Science Institute.

After that, things slowed down a lot, but in recent years there’s been something of a renaissance in the solar system.

“The first decade of the 21st Century has been as good as, if not better than, the golden age,” Hobbs believes. “Some people have called it the platinum age of planetary exploration. And if there’s a flagship of that platinum age of planetary exploration it’s got to be the Cassini-Huygens spacecraft.”

Hobbs gave a talk about Cassini, titled “Seven Years in the Saturn System,” last month at the museum. The presentation featured lots of the spectacular photography from the mission, including the discovery of seasonal colors on the second-largest planet in the solar system. Hobbs also discussed discoveries about Saturn’s rings and the intense study of the huge moon Titan. But the most fascinating part of the talk centered on the moon Enceladus, which Hobbs says has joined the astrobiologists’ short list, along with Mars and Europa, for further study.

That’s largely because of the discovery of enormous geysers at the south pole of Enceladus, which spew out ice crystals that form Saturn’s E-ring and cover Enceladus with fresh snow, making it one of the brightest objects in the solar system. The interesting thing about the E-ring is that it contains salt.

“The salt had to come from somewhere,” Hobbs explained, “so somewhere down in Enceladus there must be water in association with hot rocks. So you’ve got an energy source, you’ve got water. We don’t know yet, but maybe we have organic chemicals. If we do, this becomes one of the likeliest places we could find life in the solar system.

“Enceladus has rapidly become one of the most important bodies for us to study,” he added.

Cassini’s work in the Saturn system is planned to continue until the summer of 2017, when it will make a handful of spectacular proximal orbits very close to Saturn’s cloud tops before it runs out of fuel and is crashed into the ringed planet.

That’s presuming Cassini keeps working. Hobbs notes that while the warranty has long since expired, the school bus-sized craft hasn’t missed a beat since it was launched in 1997.

“Space is a harsh environment, particularly when you go a billion miles from the Sun,” Hobbs noted. “It gets cold out there, and every time you go into the shadow of Saturn or one of the moons, it drops dramatically. So given our experience with technical things, it is kind of a surprise” that Cassini is still functioning, he said. “On the other hand, we in America seem to be building some really good stuff these days.”

It will be fascinating to see what wonders Cassini finds before the mission ends five years from September.

On a road trip to Mars

There may be no better measure of the advance of technology during the space age than a count of photographs from Mars missions. Mariner 4 shot fully 21 pictures when it flew by Mars in 1965. Nearly half a century later, the Mars Exploration Rovers Spirit and Opportunity have returned more than 270,000 images from the surface of the Red Planet.

Mariner 4 image showing craters in the Memnonia
Fossae region of Mars. Some folks were still
expecting canals. Photo: NASA, NSSDC.

Ron Hobbs calls the rovers “one of the incredible feats of the space age.” Hobbs, a NASA solar system ambassador, gave a talk titled “The Great Martian Road Trip” during Mars Fest last Saturday at the Museum of Flight in Seattle.

While there weren’t many photos from Mariner, Hobbs said there were enough to debunk a century of belief that there might be a civilization on Mars. Mariner found not canals but craters.

“Overnight Mars went from a place that might have intelligent Martians building civilizations and canals to a place not much different from the Moon,” Hobbs said.

We followed the Mariner mission with the Vikings, which were equipped to look for signs of life.

“At that point we still believed that Mars could be habitable,” Hobbs noted. And the Viking landers actually found signs of life.

“But there was a problem,” Hobbs said. “There were no dead bodies. There was no organic material in the soil.”

With that, scientists concluded there wasn’t much happening on Mars, and we lost interest for a couple of decades. Oddly enough, Viking I may well have found organics, but just didn’t see them. A couple of years ago the Phoenix lander found perchlorates in the soil of Mars, and perchlorates would have masked any organics that Viking may have come across.

Spirit and Opportunity have clearly been the sexy rovers that have captured our imaginations. Hobbs recalled that the museum had a Mars Fest in 2004; Spirit was already on Mars, and Opportunity landed later that night.

“Nobody would have imagined that seven years later at least one of them would still be roving the Martian surface,” he marveled. Spirit is stuck in the sand and quiet, but Opportunity is still rolling and working.

The Museum of Flight had a full-size model of the Mars Science
Lab Curiosity on exhibit last year. The real one is set to launch
this fall. The auto-sized rover includes a rock-zapping laser.
Photo: Greg Scheiderer.

The next generation of Mars rover is Curiosity, an automobile-sized rover that is scheduled to launch later this year. It’s a complex geochemical laboratory that Hobbs said has a broader mission.

“In addition to looking for water, NASA is now beginning to look for organic materials, that is, carbon-based materials on Mars,” Hobbs said. “The mantra is shifting now from follow the water to follow the carbon.”

Hobbs is enthusiastic about the Mars missions.

“I don’t need any justification for exploring,” he said, adding that his own curiosity compels him to climb hills to see what’s on the other side. “But I do hope that what we’re learning on Mars and some of the other worlds of the solar system will help us protect the only planet that we know of right now where there’s life.”