NATIONAL HARBOR, Md. — Scientists involved with NASA’s New Horizons mission showed off the latest analysis of data collected during the spacecraft’s flyby of Pluto in July, despite “organizational confusion” at the event that mistakenly prevented attendees from initially sharing the results with the public.
The results of an initial analysis of the data returned to date from the spacecraft, presented during sessions of the annual conference of the American Astronomical Society’s Division for Planetary Science (DPS) here Nov. 9, include the discovery of possible ice volcanoes on the surface of Pluto and an atmosphere colder and more compact than previously expected.
“Pluto and its system of satellites has really outsmarted us,” said Alan Stern, principal investigator of the New Horizons mission, during a press conference about some of the results presented at the conference. The surprises scientists have discovered about the distant world, he said, stem from a “vast variety of landforms” seen on its surface and evidence for changes to it over time.
One of the major findings presented at the conference was the discovery of a pair of mountains, informally named Wright Mons and Piccard Mons. The shapes of the mountains, and the presence of depressions at the summits, suggest to scientists that they are volcanoes that would erupt ice, rather than molten rock.
“Nothing like this has ever been seen in the outer part of the solar system,” said Oliver White of NASA’s Ames Research Center. If that explanation is correct, he said, “that would be one of the most phenomenal discoveries of New Horizons and make Pluto an even more fascinating and unique place.”
Other results from the conference showed that Pluto’s tenuous atmosphere — its surface pressure is only ten millionths that of the Earth’s atmosphere — is colder and more compact than initially expected. That suggests that far less of the atmosphere is escaping to space than expected.
“This changes our thinking of the long-term evolution of Pluto and its atmosphere,” said Leslie Young of the Southwest Research Institute. That includes losing far less of the ice on Pluto’s surface than originally thought. “The atmosphere has some huge implications for the history of the geology of Pluto.”
The DPS conference is the first scientific meeting where scientists involved with New Horizons have presented results since July’s flyby. “That is the milestone that really marks the beginning of the scientific process,” said Curt Niebur, a program scientist working in the planetary sciences division of NASA Headquarters. “This is when the debates begin.”
However, that debate of the findings was initially limited to the people attending the meeting. Attendees of the morning conference sessions Nov. 9 were told that the results were embargoed until a midday press conference. This prevented both scientists and reporters from sharing the results presented in those talks to the public, including through social media, much to the consternation of some in attendance.
Sources at the conference blamed the embargo on NASA, in contrary to the conference embargo policy established for conferences run by the American Astronomical Society. Niebur said later that the embargo was a misunderstanding that won’t apply to other sessions during the week-long conference. “There was some kind of miscommunication,” he said. “There was a little bit of organizational confusion.”
Members of the mission team emphasized that the results are still preliminary, based on just the small fraction of the data returned to date. Stern said only about 20 percent of the flyby data has been transmitted so far, given the spacecraft’s distance from the Earth and access to the Deep Space Network. It will take about a year to transmit the remaining data. “You can either be frustrated that the data is not on the ground, or you can just look of it as new presents landing every week,” said Stern.
And, with only that preliminary data, some scientists were cautious about making many conclusions. John Spencer of the Southwest Research Institute, in a talk about searches for small moons and dust surrounding Pluto, decided not to discuss any implications of the findings to date. “We have no idea what any of this means at this point,” he said.