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New Horizons Spacecraft Completes Flyby of Ultima Thule, the Most Distant Object Ever Visited NASA’s New Horizons Spacecraft Signals Successful Flyby of Ultima Thule, the Most Distant Object Ever Visited
(about 9 hours later)
LAUREL, Md. — Midnight at the Johns Hopkins Applied Physics Laboratory looked like any other New Year’s Eve party around the world. The scientists, engineers and well-wishers in attendance counted down and cheered the start of 2019. LAUREL, Md. — Thirty-three minutes after midnight, scientists, engineers and well-wishers here at the Johns Hopkins Applied Physics Laboratory celebrated the moment that NASA’s New Horizons spacecraft made its closest approach to a small, icy world nicknamed Ultima Thule.
Thirty-three minutes later, they counted down again, this time for the real reason they had gathered. The New Horizons spacecraft, operated by the laboratory for NASA, was approaching a small, icy world nicknamed Ultima Thule, which lies a billion miles farther from the sun than Pluto and could hold clues to the formation of the solar system as we know it. Almost 10 hours later, the New Horizons team, based at the laboratory, finally received confirmation that the spacecraft had indeed done everything they had asked. In the days and months to come, the mission’s scientists expect to receive pictures of Ultima Thule and scientific data that could shed light on how the sun and planets formed during the solar system’s earliest days.
“Are you psyched?” said S. Alan Stern, New Horizons’ principal investigator, surrounded by children waving American flags. “Are you jazzed?” During the flyby, the spacecraft was busy making scientific observations and out of communication. Only hours later did New Horizons turn its antenna toward Earth to send a 15-minute update on its status — no pictures or data from the flyby yet. The message took six hours to travel the 4.1 billion miles at the speed of light to Earth.
At the moment Dr. Stern marked the spacecraft’s closest approach, the crowd cheered, more loudly than they had for the new year. At 10:31 a.m., the mission operations center at Johns Hopkins confirmed that radio dish in Madrid, Spain, part of NASA’s Deep Space Network, had locked in to the signal from New Horizons.
“Go, New Horizons!” Dr. Stern shouted. “We have a healthy spacecraft,” Alice Bowman, the mission operations manager, announced following a methodical check of the spacecraft’s systems. “We are ready for Ultima Thule science transmission.”
Although calculations by the mission's managers predicted that the spacecraft would pass within 2,200 miles of the small world, known by the designation 2014 MU69, at 12:33 a.m. Eastern time on Tuesday, scientists still have to wait hours to learn whether the mission was a success. On Monday, the people working on the mission had expressed confidence that everything had gone as planned. “But I’d be kidding you if I didn’t tell you that we’re also on pins and needles to see out how this turns out,” S. Alan Stern, the mission’s principal investigator had said in a news conference. “We only get one shot at it.”
“We’re very confident in the spacecraft, and we’re very confident in the plan that we have for the exploration of Ultima,” Dr. Stern said on Monday. “But I’d be kidding you if I didn’t tell you that we’re also on pins and needles to see out how this turns out. We only get one shot at it.” Tuesday morning, Dr. Stern expressed a more jubilant mood on Twitter.
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At that time of closest approach, the spacecraft was busy making its scientific observations. Only hours later was it scheduled to turn its antenna toward Earth to confirm whether everything had gone as planned. That 15-minute message, which does not contain images or other scientific data, would then take six hours to travel the 4.1 billion miles at the speed of light to Earth. The night before, revelers at the lab, which manages the mission for NASA, celebrated both the start of 2019 and the flyby, and they were treated to Brian May, best known as the lead guitarist of the rock band Queen but also an astrophysicist collaborating with the mission’s science team, introducing a music video of a new song, “New Horizons,” which he wrote for the occasion at the request of Dr. Stern.
The New Horizons team will be waiting at 10:28 a.m. on Tuesday for the start of this “phone home” communication.
Between the start of 2019 and the time of the flyby, the revelers were treated to Brian May, best known as the lead guitarist of the rock band Queen but also an astrophysicist collaborating with the mission’s science team, introducing a music video of a new song, “New Horizons,” which he wrote for the occasion at the request of Dr. Stern.
New Horizons to exploreNew Horizons no one has ever seen beforeNew Horizons to exploreNew Horizons no one has ever seen before
Dr. May said he was initially reluctant when Dr. Stern asked. “I thought this is going to be hard, because I can’t think of anything that rhymes with Ultima Thule,” he said.Dr. May said he was initially reluctant when Dr. Stern asked. “I thought this is going to be hard, because I can’t think of anything that rhymes with Ultima Thule,” he said.
For most of the rest of his time here, Dr. May was working with other scientists. “I’m not here as a celebrity,” he said. For most of the rest of his time here, Dr. May is working with other scientists. “I’m not here as a celebrity,” he said.
There was plenty of work to be done. In many ways, this flyby was more difficult than the one for Pluto in 2015, which collected a wealth of fascinating pictures and data. Ultima Thule is about one-100th the diameter of Pluto and far dimmer. While Pluto has been studied for decades, Ultima Thule was discovered only four and a half years ago by the Hubble Space Telescope, and none of the telescopes on Earth have been able to clearly spot it.There was plenty of work to be done. In many ways, this flyby was more difficult than the one for Pluto in 2015, which collected a wealth of fascinating pictures and data. Ultima Thule is about one-100th the diameter of Pluto and far dimmer. While Pluto has been studied for decades, Ultima Thule was discovered only four and a half years ago by the Hubble Space Telescope, and none of the telescopes on Earth have been able to clearly spot it.
If Ultima Thule was not where the scientists thought it was, the cameras and other instruments could have been pointing at empty space instead. At closest approach, New Horizons snapped a swath of almost 900 of the highest-resolution images to make sure that the object shows up in a few.If Ultima Thule was not where the scientists thought it was, the cameras and other instruments could have been pointing at empty space instead. At closest approach, New Horizons snapped a swath of almost 900 of the highest-resolution images to make sure that the object shows up in a few.
Still, the New Horizons team was confident that it had pinned down where it would be. For years, scientists performed laborious astronomical studies all around Earth, seeking additional clues about the shape and orbit of the object. The New Horizons spacecraft itself was first able to spot Ultima Thule beginning in August, although as no more than a speck of light until this weekend. As the spacecraft approached, scientists had expected to see a rhythmic brightening and dimming of Ultima Thule, which would reveal how fast it is spinning. Instead, the brightness seems to have remained steady the whole time.
“I think we're good,” said Marc W. Buie, an astronomer working to identify Ultima Thule’s position, during a news conference on Sunday. “I think we're better than good.”
In the last couple of years, there were several fortuitous times when Ultima Thule passed in front of a distant star, causing the starlight to vanish briefly, what astronomers call an occultation. That tells them that Ultima Thule was along the line of sight between Earth and the star.
Using the information from the occultations, the spacecraft navigators believe they had calculated the time of the nearest approach to Ultima Thule to within six or seven seconds, Dr. Buie said.
Those occultation observations also showed that the object is not a sphere, but rather elongated like a long potato or perhaps two bodies touching each other.
New Horizons itself was able to spot Ultima Thule beginning in August, although as no more than a speck of light until this weekend. As the spacecraft approached, scientists had expected to see a rhythmic brightening and dimming of Ultima Thule, which would reveal how fast it is spinning. Instead, the brightness seems to have remained steady the whole time.
“It’s really puzzling, because we know the shape is irregular,” Dr. Stern said.“It’s really puzzling, because we know the shape is irregular,” Dr. Stern said.
On Monday, scientists showed an image where Ultima Thule was finally larger than a single dot of light, again indicating an elongated shape.On Monday, scientists showed an image where Ultima Thule was finally larger than a single dot of light, again indicating an elongated shape.
Over the next couple of days, preliminary looks at the data, including what the scientists hope will be striking images of Ultima Thule, will be beamed back to Earth. Twenty months will pass before scientists have the full set of measurements. And they will be eagerly awaiting every bit of that stream.Over the next couple of days, preliminary looks at the data, including what the scientists hope will be striking images of Ultima Thule, will be beamed back to Earth. Twenty months will pass before scientists have the full set of measurements. And they will be eagerly awaiting every bit of that stream.
“We are ready to science the heck out of Ultima Thule,” Dr. Stern said.“We are ready to science the heck out of Ultima Thule,” Dr. Stern said.