LAUREL, Md. — Hundreds of well-wishers took part in a different kind of New Year’s countdown, 33 minutes past midnight, to celebrate the moment when NASA’s New Horizons spacecraft flew past an icy object known as Ultima Thule, more than 4 billion miles away.
The revelers here at Johns Hopkins University’s Applied Physics Laboratory didn’t yet know for sure whether the piano-sized probe actually survived the encounter. Because of the complicated schedule for New Horizons’ observations, plus the 6-hour-plus time it takes for radio signals to travel from Ultima Thule to NASA’s Deep Space Network, definitive word of success (or failure) won’t come until hours later on New Year’s Day.
Despite the uncertainty, tonight’s gathering had many of the trappings of a New Year’s Eve party, including sparkling wine and party hats. Mission team members and New Horizons’ fans, plus family members, noshed on hors d’oeuvres and watched presentations and performances (including a sing-along in New Horizons’ honor) during the buildup to 12:33 a.m. ET (9:33 p.m. PT Dec. 31).
Just after midnight, rock-star astrophysicist Brian May — who has gained fame for his 3-D astronomical imagery as well as for his riffs as lead guitarist for the rock group Queen — unveiled the full version of a rock anthem he wrote for the occasion.
New Horizons principal investigator Alan Stern said the mission’s results could rock planetary science to a similar degree. Tonight’s event marked history’s farthest-out encounter with a celestial body, in an icy outer region of the solar system known as the Kuiper Belt.
“We are going to change what we know about the Kuiper Belt literally overnight,” Stern told the audience during one of the pre-flyby panel discussions.
The encounter with Ultima Thule (“Ul-ti-ma Too-lee,” from a Latin phrase that basically signifies “a place beyond the known world”) comes almost 13 years since New Horizons was launched in 2006, and three and a half years since the probe flew past Pluto in 2015. The mission team selected Ultima, whose formal name is 2014 MU69, after using the Hubble Space Telescope to seek out targets for an extended mission.
Seven scientific instruments were reprogrammed to observe Ultima Thule and its environment. In the hours before the flyby, radio signals were beamed from Earth toward the spacecraft in hopes of getting reflected readings relating to Ultima’s composition. Imagers and spectrometers captured hundreds of photos as the spacecraft buzzed within 2,200 miles of the 20-mile-wide agglomeration of ice and rock, at a relative speed of 32,000 mph. Other instruments monitored the solar wind, energetic particles and dust concentrations in Ultima’s vicinity.
Unlike Pluto, which is a billion miles closer in, Ultima Thule is thought to be relatively unchanged since the formation of the solar system more than 4.5 billion years ago. “It’s probably the most primitive object ever encountered by a spacecraft,” mission project scientist Hal Weaver said in advance of the flyby.
But mission managers acknowledged that they didn’t know exactly what New Horizons would send back. “Anything’s possible,” deputy project scientist John Spencer said.
A highly processed image, acquired 37 hours before the flyby, showed a fuzzy view of what appeared to be an elongated object that’s been compared to a peanut. Progressively better images should be released starting on New Year’s Day.
The New Horizons team is expected to receive a 15-minute “Phone Home” transmission that reports the health of the spacecraft and all its instruments at about 10 a.m. ET (7 a.m. PT). That will be followed by an 11:30 a.m. ET (8:30 a.m. PT) news conference, during which team leaders will share findings that were sent back to Earth before the time of closest approach. Those findings should include a processed version of six-pixel imagery that shows Ultima’s shape more definitively.
The first images and other science data from the close flyby itself are to be shared at a news conference on Wednesday, and even higher-fidelity results will be released on Thursday.
Because of the power limits for New Horizons’ transmitter, plus the extreme distances involved, the spacecraft will be sending back data at a rate of only 1,000 bits per second. New Horizons’ mission managers figure it will take 20 months to send back the roughly 6 gigabytes of science data that the spacecraft should have stored in its memory banks during the encounter.
The New Horizons mission is a partnership involving NASA as well as the Applied Physics Laboratory, which is in charge of mission operations; and the Southwest Regional Institute, which is Stern’s home institution. Because APL manages the mission on NASA’s behalf, the partial government shutdown hasn’t had a major impact on operations. However, NASA representatives on the team either had to get special authorization or sit out this week’s proceedings.
One NASA official who did get the go-ahead to take part was Associate Administrator Thomas Zurbuchen, who heads the space agency’s Science Mission Directorate. During one of tonight’s pre-flyby panels, he noted that NASA was spending $6 billion over the course of a decade on missions targeting small celestial bodies, including Ultima Thule as well as an assortment of asteroids.
“For me, that’s why I’m here,” he told the crowd at APL. “To show that presence, to really be here for these missions as we do these very challenging maneuvers.”
Zurbuchen may well have yet another mission to juggle: In the months ahead, Stern and his colleagues hope to start laying plans for yet another New Horizons extension, to target another Kuiper Belt object that’s yet to be identified. And another party will no doubt be part of the plans.