In the midst of political turmoil that has probably left many of the people gathered together at John Hopkins University Applied Physics Laboratory working without pay or even furloughed, there was a different kind of excitement as 2019 rolled in: New Horizons was flying past Ultima Thule.
At 12:33 AM EST, the intrepid New Horizons probe, which gave us the first look at the demoted dwarf-planet Pluto in 2015, passed within 2,200 miles of an object in the Kuiper belt designated 2014 MU69.
An online poll conducted by NASA to find an appropriate nickname for the object produced a clear winner: Ultima Thule, Latin for “beyond what is known,” which is as fitting a name as one can come up with.
Ultima Thule is, in fact, the farthest object from Earth that has ever been visited by a human-made probe.
New Horizons Gives Its All for Mankind
The New Horizons probe is dying.
Specifically, there is only has so much fuel that could be fit onboard a probe the size of a washing machine, and soon it will use up the last bit of nuclear material that powers its systems: a canister full of decaying plutonium.
This is supposed to happen since most probes are one-shot affairs meant to gather a specific dataset and call it a day. For New Horizons, this could easily have been its fate after the probe flew past the primary target of its original mission.
In 2015, the New Horizons probe woke from a several-year-long slumber as it made its final approach toward the dwarf planet Pluto, the target of its mission.
The images it sent back of the beloved celestial object were mesmerizing. Fittingly, the iconic image of New Horizons’ mission was one of a gigantic white heart-shaped glacier that covers a large part of the visible planet.
This glacier is the largest one in the solar system that we know of, but to the world audience—many of whom were distressed over Pluto’s demotion several years ago to a dwarf planet—that fact was lost to the emotion of the moment.
Once it was discovered in the early 20th century, the words used to describe Pluto were the considerably bleak: Inhospitable, Cold, Remote, Icy.
Pluto is absolutely all of those things, but with this image fresh in people's minds, New Horizons beamed back a world that had much more personality than people were expecting.
Response to New Horizons’ Success
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Gorgeous Pluto! The dwarf planet has sent a love note back to Earth via our New Horizons spacecraft, which has traveled more than 9 years and 3+ billion miles. This is the last and most detailed image of Pluto sent to Earth before the moment of closest approach, which was at 7:49 a.m. EDT Tuesday - about 7,750 miles above the surface -- roughly the same distance from New York to Mumbai, India - making it the first-ever space mission to explore a world so far from Earth. This stunning image of the dwarf planet was captured from New Horizons at about 4 p.m. EDT on July 13, about 16 hours before the moment of closest approach. The spacecraft was 476,000 miles (766,000 kilometers) from the surface. Images from closest approach are expected to be released on Wednesday, July 15. Image Credit: NASA/JHUAPL/SwRI #nasa #pluto #plutoflyby #newhorizons#solarsystem #nasabeyond #science
The images New Horizons sent back to Earth generated considerable press attention and invigorated the imaginations of millions of people around the world that would not otherwise have given much thought to Pluto.
we got close to Pluto only to find it has a heart on it.. Pluto loved us all along— aliza layne (@alizabees) July 14, 2015
This goes a long way to explaining why people who don’t keep up with every new development in space exploration have heard of New Horizons. One of NASA’s main goals is to generate public interest in space exploration and on that note, New Horizons has been one of the most successful missions NASA has carried out in recent years.
But once the mission to Pluto was complete, what then? New Horizons could easily have been left to sail off into space now that its primary mission was finished, but scientists at NASA decided that New Horizons wasn’t ready to retire just yet.
Probing the Origins of the Solar System
Scientists at NASA looked at what was in the range of the New Horizons future trajectory and looked for anything that New Horizons could visit before its fuel ran out and it would be unable to broadcast its finding back to Earth.
They soon identified an object in the Kuiper Belt—a ring of rocks and ice that contains the leftover material used to build the solar system billions of years ago—that was within the range of the probe.
Earth, Mars, and even Pluto were all created billions of years ago out of the same kind of material that fills the Kuiper Belt, so these leftover building blocks have been of considerable interest to scientists hoping to better understand the conditions that existed at the very beginning of the solar system.
NASA approved a new mission for New Horizons: 2014 MU69, a chunk of rock and ice more than a billion miles away from Pluto.
The mission was particularly challenging. At such a great distance, very little could be seen from earth of the object so very little was known about the risks to the probe.
No one knew if there would be a debris field in between New Horizons and Ultima Thule that could have been dangerous for the probe to approach. In the inner solar system, the gravitational fields of planets clear its particular neighborhood of any debris, but what is the Kuiper Belt but a gigantic ring of debris that no planet has cleared out?
Traveling about ten miles every second, an impact with even a tiny bit of debris could be enough to destroy the probe before reaching its target, so scientists knew that there were risks to the probe and planned accordingly.
Different paths were planned, depending on whether or not New Horizons detected debris on its main trajectory, and everyone acknowledged that there is always a chance of something unforeseen bringing New Horizons mission to an abrupt end.
Once More Into the Breach
As New Horizons began its final approach, scientists were encouraged to find that there wasn’t any debris around Ultima Thule.
This meant the probe could take the closest approach to the Kuiper Belt object, flying within 2,200 miles of it, close enough to get clearer images of the object and record better data about its composition.
As the scheduled fly-by on January 1st approached, excitement started to build. Scientists and journalists gathered at the Kossiakoff Center at the John Hopkins University Applied Physics Laboratory in Maryland to ring in the New Year with a celebration of the fly-by, which occurred at 12:33 AM EST.
“This has to be the nerdiest New Year’s Eve I could imagine,” someone joked in the lead up to the celebration. Brian May, the guitarist for the legendary rock band Queen who is also an astrophysicist who contributed to the New Horizons mission, debuted a song about New Horizons for the occasion.
NASA officials, dealing with the effects of a government funding crisis, attended the event as private citizens. “I’m just a planetary scientist,” said Jim Green, head of NASA’s planetary science division, “and in a planetary event, wild horses can’t drag you away.”
It would be several hours before anyone on Earth would know whether New Horizons had succeeded. Billions of miles is a long way for a signal from the probe to travel, so everyone waited for confirmation to come around 10:30 AM on New Year’s Day.
The signal arrived on schedule, and as one scientist reported the successful recording of the data from Ultima Thule, cheers erupted outside mission control to celebrate one more successful mission for New Horizons.
Twilight for New Horizons?
It was a historic achievement for the probe and the entire team of scientists and engineers who have worked for over a decade to make this all possible. New Horizons is the first probe ever to analyze an object that had been discovered after the probe had already launched.
Scientists are now hard at work looking to see if there might be one last object for New Horizons to study before its final transmission home. “It’s a pretty low chance, but it’s worth a look, and we’re going to try,” according to a member of the New Horizons team, Kelsi Singer.
They are even using New Horizons own instruments to scan for possible targets in range. If successful, this would further cement New Horizons place in history, making it the first probe that ever discovered its own mission target.
Whatever comes next for New Horizons, it has already proven itself to be one of the most incredible instruments ever produced, on par with the Voyager probes and the Curiosity rover on Mars.
Whether or not Ultima Thule is New Horizons’ final target, its stunning success—and that of the team of scientists who made it all possible—make New Horizons one of mankind’s greatest achievements.