Pluto’s first official surface-feature names are marked on this map, compiled from images and data gathered by NASA’s New Horizons spacecraft during its flight past Pluto in 2015. (IAU Map)
Some of the best-known places on Pluto, including the heart-shaped Tombaugh Regio, have finally gone legit. But lots of other places, such as Cthulhu Regio, are still in the dark.
The decision from the IAU’s Working Group for Planetary System Nomenclature comes more than two years after NASA’s New Horizons probe flew past Pluto and gave scientists their first-ever detailed look at the dwarf planet.
A composite image shows Pluto (lower right) and Charon (upper left). Credit: NASA / JHUAPL / SwRI
It’s taken a year and a half, but the International Astronomical Union and the science team behind NASA’s New Horizons mission have finally struck a deal for naming the features on Pluto and its moons.
The agreement, announced today, will open the way for the already well-known “informal” names for places on Pluto, such as Tombaugh Regio and Sputnik Planum, to become formal.
It also allows for features on Charon, Pluto’s biggest moon, to be officially associated with fictional characters and locales – including Mordor from “Lord of the Rings,” Mr. Spock from “Star Trek” and Princess Leia from “Star Wars.”
Sputnik Planitia, the left lobe of Pluto’s “heart,” is thought to have formed as the result of a giant impact early in the dwarf planet’s history. This graphic shows how the icy world reoriented itself as the impact basin filled with volatile ices. (Credit: James Keane / University of Arizona)
Pluto’s famous heart-shaped feature may well have migrated over the course of millions of years as the dwarf planet spun, and that would add to the evidence for a slushy ocean hidden beneath the ice, two groups of scientists say.
In separate reports published today by the journal Nature, the scientists say a reorientation of the faraway world’s most famous feature would provide the best explanation for phenomena observed during last year’s flyby of NASA’s New Horizons probe – including patterns of cracks in the ice.
Most tellingly, it would explain why the heart-shaped feature, known informally as Tombaugh Regio, lines up almost precisely opposite Pluto’s biggest moon, Charon.
“We asked, ‘What’s the chance of that randomly happening?’ And it’s less than 5 percent that it would be so perfectly opposite,” MIT Professor Richard Binzel, a co-author of one of the reports, said in a news release. “And then the question becomes, what was it that caused the alignment?”
An artist’s conception shows the New Horizons spacecraft beaming data back to Earth. (Credit: NASA / JHUAPL / SwRI)
More than 15 months after NASA’s New Horizons spacecraft flew past Pluto, the last bit of data captured during the flyby has finally been transmitted back to Earth.
NASA said the final transmission was a digital segment of an observation sequence captured by New Horizons’ Ralph/LEISA imager, focusing on Pluto and its biggest moon, Charon. The readings were stored up on July 14, 2015, as the piano-sized probe zoomed past Pluto about 3 billion miles from Earth. Since then, New Horizons’ distance from Earth has grown to 3.4 billion miles.
The downlink took place at 2:48 a.m. PT Oct. 25 via NASA’s Deep Space Network station in Canberra, Australia. In all, more than 50 gigabits of data relating to Pluto and its moons have been transmitted back to Earth.
Why did it take so long to send back an amount of data that would basically fit on a thumb drive?
The left side of Pluto’s bright “heart” is known informally as Sputnik Planum. (Credit: NASA / JHUAPL / SwRI)
Scientists have been saying for months that Pluto could have a salty, sloshing ocean beneath its icy surface, but now they’ve worked out just how deep it could go. The answer? As deep as 60 miles, or nine times the depth of Earth’s deepest seas.
The estimate, based on computer modeling of the impact dynamics behind a heart-shaped region of Pluto, was published this month in Geophysical Research Letters.
The bright-colored “heart,” first seen last year by NASA’s New Horizons probe, is arguably Pluto’s best-known surface feature. But it’s actually two features. Scientists say the left lobe of the heart, known informally as Sputnik Planum, was created in the aftermath of an ancient impact. The object that made that impact is thought to have been about 120 miles (200 kilometers) wide.
In June, researchers reported that the geological features mapped on Pluto’s surface would be consistent with the presence of a liquid water ocean far below, perhaps heated by the decay of radioactive materials in Pluto’s rocky core. But they didn’t estimate the size of the ocean.
NASA’s New Horizons spacecraft captured this high-resolution, enhanced color view of Pluto’s largest moon, Charon, just before closest approach on July 14, 2015. Scientists have learned that reddish material in the north (top) polar region – informally named Mordor Macula – is chemically processed methane that escaped from Pluto’s atmosphere onto Charon. (Credit: NASA / JHUAPL / SwRI)
When NASA’s New Horizons probe sent back pictures of Pluto’s largest moon, Charon, researchers were surprised to see a big red spot on its north pole. More than a year later, they’ve published their best explanation for its origin.
The process begins when molecules of methane escape from Pluto’s thin atmosphere. Those molecules are drawn to Charon, a mere 12,200 miles away, by the moon’s gravitational pull. The rarefied methane gas freezes out and settles onto the surface as ice.
Methane ice piles up when it’s winter in the north, but when the season turns toward spring, the northern polar region is exposed to sunlight. The sun’s ultraviolet rays cook the methane into a mix of hydrocarbons.
As the ice warms up, any methane that remains thaws back into gas. But the heavier hydrocarbons stick around on the surface, and get cooked into reddish organic compounds known as tholins.
The 1991 stamp that served as the rallying cry for the New Horizons Mission to Pluto is “updated” by members of the New Horizons science team on July 14, 2015, the day the spacecraft reached Pluto. (Credit: Bill Ingalls / NASA)
We’ve known for years that a 1991 Pluto stamp included on NASA’s New Horizons spacecraft is the farthest-out piece of postage, but now the U.S. Postal Service and Guinness World Records have officially put it in the record books.
The message on the stamp, “Pluto: Not Yet Explored,” was basically canceled a year ago when New Horizons flew past the dwarf planet, taking pictures as it zoomed by at 36,000 mph.
To celebrate the record – and the New Horizons achievement that rendered the stamp obsolete – the USPS played host to the New Horizons team and Guinness World Records adjudicator Jimmy Coggins today at its Washington headquarters. Coggins presented a certificate recognizing the record to the Postal Service’s Jim Cochrane, NASA’s Jim Green and the Southwest Research Institute’s Alan Stern, who is the principal investigator for the New Horizons mission.
“The farthest distance traveled by a postage stamp is a quite an impressive achievement, as it spans many planets and billions of miles. As stamps are synonymous with travel, it is fitting that one would travel within the solar system,” Coggins said in a news release. “It’s an honor to be a part of this historic moment and welcome the United States Postal Service to the Guinness World Records family.”
“It’s strange to think that only a year ago, we still had no real idea of what the Pluto system was like,” project scientist Hal Weaver, who’s based at the Johns Hopkins University Applied Physics Laboratory, said in a news release celebrating the anniversary. “But it didn’t take long for us to realize Pluto was something special, and like nothing we ever could have expected.”
After more than nine years of cruising through interplanetary space, the piano-sized New Horizons spacecraft flew by Pluto and its moons at a speed of more than 30,000 mph on July 14, 2015, capturing readings as it went. Since then, the probe has been transmitting gigabytes’ worth of data back to Earth at a slow but steady rate.
The pictures have been unprecedented, providing the first close look at icy worlds that whirl more than 3 billion miles from the sun, in a region known as the Kuiper Belt. They’ve even inspired a set of postage stamps.
Artwork shows New Horizons flying by a Kuiper Belt object known as 2014 MU69. (Credit: NASA)
Almost a year after New Horizons’ unprecedented flyby of Pluto, NASA has given the official go-ahead for the probe to fly past another icy object in the Kuiper Belt in 2019.
At the same time, the space agency decided to keep the Dawn spacecraft in orbit around the dwarf planet Ceres, rather than sending it out to another asteroid known as Adeona.
The decisions are part of NASA’s process for extending its planetary missions into the 2017-2018 time frame.
New Horizons’ extension means that mission operations will be supported as the piano-sized probe makes its way toward a Kuiper Belt object called 2014 MU69. The object was detected in 2014 during a Hubble Space Telescope search for post-Pluto targets that could be reached by New Horizons. The mission team already has been maneuvering the spacecraft in preparation for a flyby on Jan. 1, 2019.
New Horizons spied extensional faults on Pluto, a sign that the dwarf planet has undergone a global expansion possibly due to the slow freezing of a subsurface ocean. (Credit: NASA / JHUAPL / SwRI)
Pluto is one of the coldest places in the solar system, but scientists say geological activity could still keep an ocean’s worth of water liquid beneath the dwarf planet’s surface.
Brown University’s Noah Hammond and his colleagues lay out their argument in a paper published in Geophysical Research Letters.
Readings from NASA’s New Horizons probe have shown that Pluto possesses mountains of water ice that rise as high as 11,000 feet, and there’s also evidence of tectonic activity associated with that ice. The newly published paper looks into the implications of those geological forces.
“Our model shows that recent geological activity on Pluto can be driven just from phase changes in the ice – no tides or exotic materials or unusual processes are required,” Hammond said in a news release. Depending on the depth of Pluto’s ice, the pressures far beneath the surface could keep water in a liquid state.
