In the center left of Pluto’s vast heart-shaped feature -- informally named "Tombaugh Regio" -- lies a vast, craterless plain that appears to be no more than 100 million years old, and is possibly still being shaped by geologic processes. This frozen region is north of Pluto’s icy mountains and has been informally named Sputnik Planum (Sputnik Plain), after Earth’s first artificial satellite. The surface appears to be divided into irregularly shaped segments that are ringed by narrow troughs. Features that appear to be groups of mounds and fields of small pits are also visible. Photo courtesy of NASA
WASHINGTON, July 17 (UPI) -- NASA researchers have "maybe" 2 percent of the data and images the New Horizons probe gathered about Pluto during its 22-hour trip past the distant planet.
Officials at the space agency excitedly released the second round of data downloaded from New Horizons, which was characterized by closer pictures and animations of the planet than have been shown yet, and theories on the makeup and movement of Pluto's atmosphere.
"I think the solar system saved the best for last," Alan Stern, New Horizons principal investigator at the Southwest Research Institute (SwRI) in Boulder, Colo., said at a press conference Friday to release more data and "beautiful eye candy" collected near the planet.
Now more than 2 million miles past Pluto, New Horizons has about 2 percent, or less than a gigabyte, of the 50 gigabytes of information it has collected. The expectation is that about 5 percent will have been sent back to Earth over the next week. NASA has scheduled a press conference for July 24 to announce the next round of pictures and information that will be released.
Pictures already sent back have shown frozen, craterless, icy plains on the planet, as well as mountains that rise as high over Pluto's surface as the Rocky Mountains are over Earth.
The plains of the Tombaugh Regio, formerly referred to as the "heart feature," are now believed to be carbon monoxide rich, and also somewhat more recent than some other parts of the planet based on the smoothness of the topography in the region.
"Let's remind ourselves that some surfaces of Pluto are marked with craters indicating its age," said Jeffrey Moore, New Horizons co-investigator at NASA's Ames Research Center. "All of this indicates that Pluto has experienced a long geographic history."
Based on the pictures sent so far, Moore said that fractures in Pluto's crust and the existence of mountainous regions means some kind of tectonics or "mountain building forces" must exist there. Additionally, he said that erosion processes appear to be functioning on the planet, based on some of what can be seen in photos.
Other areas showed mysterious pock marks and features that Moore briefly mused about the potentials of before stopping himself short. "We are in the most preliminary stages of our investigations. Jumping to conclusions comes at great peril," he said.
This second bit of data from New Horizons also is significant because researchers have been able to start informing theories that have long been held about Pluto's atmosphere, which appears to be nitrogren-based.
"We've had to wait until we were past Pluto and looking at the sun to get our best data," said Randy Gladstone, New Horizons co-investigator at SwRI in San Antonio. "We're looking forward to getting full data in a month or so."
What they know already is that nitrogen is evaporating off the surface of the planet and escaping into the atmosphere because the gravity there is much weaker than on Earth or Mars, according to Fran Bagenal, a New Horizons co-investigator at the University of Colorado. As the nitrogen enters Pluto's atmosphere, it is being picked up by solar winds.
The escaping nitrogen is ionized as it leaves the planet and is hit by the solar winds, which has created a tail of atmosphere behind the planet. "We have actually flown through this," Bagenal said, "The data we get next month will allow us to quantify the amount of that escaping atmosphere."
Over the next several months, the researchers said they will begin to get composition maps, thermal maps, and topographical maps that will allow them to learn much more about planet.
"This is the tip of the iceberg," Moore said.