Message of the Day: Environment, Personal Growth
Ultima Thule, New Year’s Day, 2019, NASA
Welcome to 2019.
We left the 2018 year-end look back up for a little more than a week purposely. We recommend as strongly as we can that you keep going back to this post to read at least most of the many important articles from throughout 2018, connected to the magnificent art in the year-end presentation in The New York Times.
Now, again, welcome to 2019.
And what a welcome.
As we posted on the Winter Solstice, Christmas Eve was the 50th anniversary of the first time humans–after leaving low earth orbit for the first time on the Winter Solstice of 1968–circled the moon, bringing us the Earthrise image that changed the way we look at the world and ourselves forever.
And then, a few days after this 50th anniversary, in the very first hours of 2019, NASA’s New Horizons spacecraft arrived at the farthest destination from Earth–4 billion miles–in history.
The place was Ultima Thule, as Sarah Kaplan in The Washington Post put it, “a rocky relic from the solar system’s infancy whose name means ‘beyond the borders of the known world.’”
Beyond the borders of the known world.
It hasn’t really sunk in yet through the ongoing toxic noise–this new horizon of human experience of the immensity of the universe and our place in it.
So let it sink in.
We have nothing more to add.
The following articles from The Washington Post and Scientific American can do the rest of the talking.
By Sarah Kaplan, The Washington Post, January 1, 2019
As Earthlings marked the start of a new year, one of the most distant spacecraft successfully explored the farthest — 4 billion miles from Earth — and most primitive objects that humans have ever seen.
NASA received confirmation Tuesday that its New Horizons probe survived its 12:33 a.m. eastern encounter with Ultima Thule, a rocky relic from the solar system’s infancy whose name means “beyond the borders of the known world.”
The midnight rendezvous occurred in the Kuiper belt, a halo of icy bodies so far from Earth it takes more than six hours for signals to travel at the speed of light to reach the Earth.
But just after 10:30 Eastern time on Tuesday, at the Johns Hopkins Applied Physics Laboratory in Laurel, Md., mission operations manager Alice Bowman turned to her colleagues with a wide grin.
The probe’s systems were working. Its cameras and recorder were pointed in the right direction.
“We have a healthy spacecraft,” Bowman announced. “We have just completed the most distant fly-by. We are ready for Ultima Thule science transmission — science to help us understand the origins of our solar system.”
At mission control, and in an APL auditorium where the rest of the science team was watching, people jumped from their seats and burst into cheers. The borders of the known world had expanded just a little bit more.
“I don’t know about you, but I’m really liking 2019 so far,” said the mission’s principal investigator, Alan Stern.
Though coincidental, the timing of New Horizons’ encounter – in the early hours of a new year – is “auspicious,” Stern said. At a moment when humanity marks the passage of time, looking forward and thinking back, New Horizons is doing the same. At 4 billion miles from Earth, Ultima Thule is the farthest celestial body scientists have ever viewed up close; it is a door to future exploration in a region that is still almost entirely unknown. But it is also a window to the past – a time capsule from the era when the planets formed, which might contain clues about how the Earth came to be.
Already, scientists are analyzing early data collected just before the moment of closest approach. An image taken from half a million miles away from Ultima Thule showed a blurry bowling pin-shaped body about 20 miles across.
Until New Horizons’s fly-by, no person had ever seen a Kuiper belt object as anything but a pinpoint of light in the distance. By Wednesday, the scientists at APL will receive their first high-resolution images of the distant rock, revealing whether it has craters, and whether it is one long object or comprises two small bodies orbiting each other.
As for answers to other questions about the Kuiper belt object, Stern advised patience. “This mission has always been about delayed gratification,” he said. “It took us 12 years to sell the spacecraft, five years to build it, 13 years to get here.”
It will take as long as 20 months for scientists to download and process all the data collected during that brief encounter.
But the resulting science will be worth the wait, project scientist Hal Weaver said. “Ultima Thule will be turned into a real world.”
New Horizons was the first mission dedicated to exploring the outermost edges of the solar system. In 2015, it took the first close-up photos of Pluto, revealing a complex and colorful world mottled with methane mountains and a vast, heart-shaped nitrogen ice plain.
When mission was first conceived in the early 1990s, no one knew what lay beyond the distant dwarf planet. But in the intervening decades, scientists discovered that the Kuiper belt – which extends from Neptune’s orbit to 5 billion miles from the sun — is home to millions of small and icy objects.
Out there, where sunlight is 0.05 percent as strong as it is on Earth and temperatures hover near absolute zero, primitive bodies like Ultima Thule have existed in a “deep freeze” since they first formed.
The Kuiper belt object, whose official name is 2014 MU69, was discovered five years ago during a sky-wide search for potential New Horizons targets after the probe left Pluto.
But the rock is so dim and so distant that even the most powerful telescopes could barely make it out. Prior to Tuesday, some of the only information about its size and shape came from coordinated observations last summer, when astronomers measured the shadow Ultima Thule cast as it passed in front of a star.
The encounter was riddled with uncertainties, making it among the more difficult feats NASA has attempted. Ultima Thule is 1 percent the size of Pluto, and New Horizons had to get four times closer to image it. At the moment of closest approach, the spacecraft was moving at a breathtaking 32,000 miles per hour. If its cameras were even slightly off track, or if scientists’ projections about Ultima Thule’s trajectory were just a little bit wrong, the probe might fail to capture useful information about its target.
Besides, New Horizons is a 13-year-old vehicle; operators must carefully prioritize their use of remaining fuel.
“This is history-making, what we’re doing, in more ways than one,” Stern said. Every image sent back from New Horizons is the most distant photograph ever taken. Each maneuver is further than anything NASA has done before.
Helene Winters, the mission’s project manager, said Monday that spacecraft operators had been subsisting on chocolate and sleeping on air mattresses at the APL so they could make the most of every minute until New Horizons reached its target. Navigators kept a watchful eye out for potential hazards, which can be hard to spot in this faraway corner of the solar system.
Asked whether she thought she would be able to sleep that night, Winters laughed. “Ask me again tomorrow.”
But as minutes to the close encounter ticked by, the atmosphere at APL was festive. Scientists and their guests munched on crudités in a room lit with sparkling blue and white lights. Small children up long past their bedtimes scurried between chairs and sneaked cookies from the buffet.
“This is like a dream come true,” said Chuck Fields, a podcast producer from Indianapolis who drove nine hours to attend Monday’s event. He was dressed in a blindingly bright blazer and tie bearing images of planets, galaxies and the sun. His wife, Dawn, wore matching pants.
NASA nodded to the encounter by counting down to 12 a.m. and distributing plastic cups of champagne. Astrophysicist Brian May, better known as lead guitarist for the rock band Queen, debuted a song he wrote for the occasion.
“This is an anthem to human endeavor,” he said.
Thirty-three minutes after the rest of the East Coast had already popped their champagne, the scientists at APL were still waiting.
Way out in the Kuiper belt, they knew, New Horizons was performing its riskiest observations yet. Particle and dust detectors were probing the chilly Kuiper belt environment. Three cameras were snapping as many images as possible in an effort to map the tiny world and determine its composition. And Ultima Thule was growing ever larger in New Horizons’s field of vision, glowing like a full moon.
“Thirty seconds to fly-by,” Stern said. “Are you ready? Are you psyched? Are you jazzed?”
Twenty seconds. Ten. And then Stern raised his hand in the air while confetti fell from the ceiling. The crowd cheered.
“New Horizons is at Ultima Thule,” Stern proclaimed.
Or so he hoped.
The following morning, New Horizons’s operators sat in mission control, anxious. Data from the Deep Space Network, a chain of radio antennas NASA uses to communicate with distant spacecraft, was displayed on their screens.
Bowman sat with her hands folded, leaning toward her computer.
“In lock with telemetry,” Bowman said.
In the APL auditorium, where the rest of the team and their families were watching, the crowd erupted.
Next came the status check: Planning — nominal. Power — green. Solid state recorders — pointed right where NASA wanted them. Every subsystem looked good. New Horizons had survived.
Thirty minutes later, members of the New Horizons mission operations team entered the APL auditorium to high-fives and riotous cheers.
“I’m not a New Year’s kind of guy,” said Mike Ryschkewitsch, the head of APL’s space exploration sector. “But I can’t think of a better reason to stay up late.”
. . .
Ultima Thule, the most-distant object ever visited by a spacecraft, is revealing our solar system’s deepest history—and, just maybe, revolutionizing planetary science
By Corey S. Powell, Scientific American, January 8, 2019
The history of the solar system is a dish best served cold. And it is so very cold on Ultima Thule.
That is the message beaming back to Earth from NASA’s New Horizons probe now that it has completed its historic exploration of a small body in the Kuiper Belt, the sprawling population of dwarf planets and cometlike objects out beyond Neptune. When New Horizons flew past at 12:33 AM Eastern time on January 1, Ultima was a hair over four billion miles from the sun. It is by far the most distant object ever visited by spacecraft, and correspondingly one of the coldest: about 35 kelvins, or nearly 400 degrees below zero Fahrenheit.
At such low temperatures, Ultima (more formally known by its scientific designation, 2014 MU69) preserves its initial, ancient composition. Ultima is also cold in another, more specialized and intriguing way. It is dynamically cold, part of what’s known as the “cold classical” Kuiper Belt, meaning that it circles the sun in a settled orbit that was undisturbed by all the chaotic events that buffeted Earth and other planets as they came together more than four billion years ago.
Prior to the encounter, the great hope of the New Horizons team was that they would see an intact survivor from the solar system’s birth. The first images of Ultima, showing its delicately stacked snowman shape, fully vindicate those hopes. It matches up exactly with models of how clouds of gas and dust around young stars clump together into larger and larger objects—a process that has been well studied in theory, but never observed in reality until now. “We’re looking at one of the first building blocks that came together to form the planets and moons,” says Jeffrey Moore, a research scientist at NASA’s Ames Research Center. “It looks like somebody left it out in the back of God’s freezer for the last four-and-a-half billion years.”
LONG WAY TO THE KUIPER BELT
Being left out in the cold is an all-too-familiar feeling for Alan Stern, principal investigator of New Horizons. He had started campaigning for NASA to mount a mission like the one to Ultima in the 1980s, long before anyone even knew Ultima existed. His original goal was to visit Pluto, completing the exploration of the then-nine planets, but the plans went nowhere. Befitting their outsider status, Stern and other like-minded outer-solar system fans called themselves the “Pluto Underground.”
Scientific interest in Pluto exploded in the 1990s, when astronomers discovered it is just one part of the much grander Kuiper Belt. Even so, Stern watched three different mission concepts wither and die. It took another decade, a cancellation, and a rare resurrection before New Horizons launched on January 19, 2006.
The probe’s nominal objective was only to visit Pluto and its moons, but from the start Stern had a second act in mind. “New Horizons is a very healthy spacecraft, and it has the power to operate for another 15 or 20 years,” he says. Why waste a once-in-a-lifetime opportunity to explore more of the Kuiper Belt? A 2015 flyby revealed Pluto as an excitingly dynamic world, but in some ways it is too dynamic: Its active geology (plutology?) has erased much of its early history. A visit to a much smaller, more pristine follow-on target would fill in a huge missing piece of the reconnaissance of the solar system.
The huge catch was that there was no suitable target in astronomers’ catalogues; the New Horizons team would have to find one themselves, something the spacecraft could reach on its dwindling stores of fuel. That meant marshaling the world’s most powerful telescopes, searching for a dim dot of light moving slowly among a thicket of background stars, located in exactly the right spot for an easy interception. Marc Buie of Southwest Research Institute (SwRI) describes his work leading that search. “I spent 10 years looking for an object for New Horizons to go to,” he says with admirable sangfroid. “I’ll let you in on a little secret: When you take photographs through a telescope, they don’t come with arrows on them to tell you what to look at.”
Finally, Buie spotted it. The telltale blip consisted of just 144 photons in a survey image from the Hubble Space Telescope, “but the instant I saw it, I got a chill. I knew it was The One.” As recognition of its importance increased, the object originally catalogued as 1110113Y became Potential Target 1, then Kuiper Belt object 2014 MU69, and most recently it was informally dubbed Ultima Thule (a name which has generated some unfortunate controversy).
When the first high-resolution images of Ultima arrived from New Horizons, all those past agonies vanished from the scientists’ minds, replaced by backslaps and oversize, unshakable grins.
“It’s a snowman!” Stern laughed as he looked at Ultima’s iconic, double-lobed shape. Or in scientific terms, he notes, it is a “contact binary,” two objects that formed separately but are now held together by their mutual gravity. The larger lobe is three times the size of the smaller one; stacked together, they measure 21 miles long.
That snowman structure is precisely what the New Horizons team was hoping to find in the Kuiper Belt. “The number-one thing I wanted to get out of this mission was incontrovertible evidence that we’re looking at a primordial, unaltered object,” Buie says. More specifically, he wanted to witness an object frozen time from the moment when small bodies in the solar system began accreting together and building up bigger ones.
On planets and moons all evidence of that process was wiped clean by subsequent geologic activity. Even on relatively primitive comets like 67/P Churyumov-Gerisamenko—the “rubber duck” comet studied until 2016 by the European Space Agency’s Rosetta probe—the surface has been extensively cooked and altered by the sun’s heat. Moore breezily dismisses such objects as “post-toasties.”
On Ultima it is as if the birth of the solar system happened yesterday, with two planetesimals (the first large conglomerations of rock, dust and ice to coalesce around a young star) still lumped together right before New Horizon’s digital eyes. “I looked at it and thought, ‘I see accretion happening’,” Buie says. “This is going to revolutionize our view of where we came from and how this whole process works.”
DO YOU WANT TO BUILD A PLANET?
In fact, the revolution is already well underway. On the first three days after the Ultima flyby, the members of the New Horizons analysis teams huddled near mission control at Johns Hopkins University Applied Physics Laboratory to make sense of the first data downloads. After all those decades of waiting, Stern is eager to get going. “We will begin writing our first science papers next week!” he promises. But really, nobody was waiting even that long to start digging into the lessons from Ultima.
One of the first orders of business is interpreting how Ultima’s two lobes came together so gently, with a tidy little necklace of brighter material rimming the place where they meet. Bill McKinnon, a planetary dynamics expert at Washington University in Saint Louis, notes objects in the Kuiper Belt are moving so slowly that typical encounter velocities would be around 600 miles per hour, which limits the amount of damage an impact can create.
Ultima apparently came together even more lightly than that. Most likely the two lobes initially formed as separate bodies in orbit around each other, spiraling together until they touched. “It would have been like a parking lot fender bender, walking speed. Also, these are probably very porous objects; they have energy-absorbing bumpers on them,” McKinnon says. As a result, the two lobes stuck together rather than shattering when they touched.
The jammed-together lobes of Ultima provide the most direct evidence yet of the standard hierarchical theory of how planets form: First dust grains stick together into pebbles, which gather into planetesimals. Those accrete into protoplanets, continuing all the way up to bigger things like Earth and Jupiter.
Another notable detail is that, other than the difference in size, the two lobes of Ultima look extremely similar in shape and color. “That’s also consistent with forming as a result of the merger of two objects that formed close together in the protoplanetary disk,” says Silvia Protopapa of the SwRI. In such a chemically and dynamically cold region two neighboring planetesimals should have aggregated from an essentially identical mix of raw materials.
Information still stored onboard New Horizons will reveal much about exactly what those materials are. “We’ll be looking for ammonia, water, carbon monoxide and organics,” Protopapa says. Ultima’s overall red tint already suggests it is covered with tholins (organic compounds processed by eons of radiation), similar to what is seen on many other outer-solar system objects, including Pluto’s moon Charon.
Moore is relieved, if maybe a little disappointed, that nothing about Ultima directly confounds expectations—as would be the case if, say, the two lobes had totally different colors. “To zeroth order, our ideas of how these things formed seem to be vindicated,” he says. “But there’s a whole range of specific explanations that people had. It’s like going into a restaurant, you can choose from any number of things on the menu. Now that we see Ultima, we know what the good choices on the menu are.”
ULTIMA’S NEXT ACT
These rapid-fire readings of Ultima are all the more impressive considering they were made by highly caffeinated scientists operating on little or no sleep, working with an initial download of just 1 percent of the total data New Horizons collected during its flyby.
Perhaps the most egregious missing data element so far is a clear look at the topography of Ultima: We can see it but we can’t really feel it. The best views released so far were taken with the sun almost directly behind the spacecraft, making it difficult to distinguish hills from depressions on the alien landscape below. Significantly sharper pictures, including ones showing deep shadows, are still sitting on New Horizons’ solid-state recorders. “It’ll take 20 months to empty the recorders of all the data we’ve taken, including hundreds of images and spectra,” Stern says. Blame the extremely limited bandwidth of a spacecraft six light-hours from home.
As the stored information trickles in, you can expect a lot more history lessons. One big hanging question for the planetary scientists is how Ultima’s individual lobes themselves were assembled. Somewhat surprisingly, there’s no unambiguous evidence for craters. There certainly are things that resemble craters, but in the calm environment where Ultima formed those poorly resolved formations might actually be hills that were built up rather than gouged-out pits. “We may find that the texture is dominated by slow-motion [accretionaary] processes,” Moore says. If so, that would reveal a lot about the early stages of planetary formation.
With that thought in mind, Cathy Olkin of SWrRI, a deputy project scientist on New Horizons, is eager to examine how the composition of Ultima varies from spot to spot. Spectral measurements from New Horizons should make it possible to identify the individual splats from ancient impact that stuck to the surface like flies on a windshield. Then she’ll do a census of the splats to understand the objects that created them. “So we will be able to look at the smallest particles in the Kuiper Belt, a population we could not see any other way,” she says.
Perhaps the most subtle but significant surprise about Ultima is that we were able to reach it at all. Recent studies of newborn stars using the Atacama Large Millimeter/submillimeter Array (ALMA) observatory in Chile show many of them seem to be forming planets across a much larger scale than what we see in our solar system, with their versions of the Kuiper Belt taking shape at far greater distances. The vast distance between our sun and Ultima does not look so vast in comparison.
McKinnon throws out another possible history lesson in there: The outer edge of our solar system may have been clipped off by radiation from neighboring stars at a very early stage, he suggests, well before even Ultima formed. “It’s probably defined by the other stars in the sun’s birth cluster, its lost brothers and sisters,” he says.
In the debate over whether our solar system is normal or a cosmic outlier, then, Ultima tips the balance a tiny bit further in the weirdo direction. “Then you consider that the sun is a single star, which is not the norm, and solar-type stars are not the most common stars,” McKinnon says. “You add it up and you think, ‘We’re not exactly a garden variety planetary system.’”
. . .
Welcome to 2019.
Welcome to the past, present and future all at once.
- Issue of the Week: Human Rights, War, Economic Opportunity
- Message of the Day: Human Rights, War, Economic Opportunity
- “Mueller Delivers Report on Trump-Russia Investigation to Attorney General” The New York Times
- “Brexit: Theresa May to urge MPs to back deal as delay agreed”, BBC News
- “The EU throws Theresa May one last Brexit lifeline”, CNN World