Hello, Pluto
After 9 years and 3 billion miles, we finally meet our far-flung cosmic cousin
Miriam Kramer
"It’s the first time in 25 years that we’ve approached an unknown world of this size." - New Horizons scientist John Spencer
We just witnessed something big.
For the first time in history, a spacecraft saw the crags and cliffs of Pluto up close, revealing a new world to humans who have been waiting patiently for more than nine years on Earth.NASA's New Horizons craft, which is the size of a baby grand piano, flew about 7,800 miles above Pluto's surface for its closest pass of the tiny planet; and as New Horizons finishes its more than 3-billion-mile journey to Pluto, it extends humanity's reach into the universe.
[img src="http://rack.2.mshcdn.com/media/ZgkyMDE1LzA3LzI0LzE1L1BsdXRvX0ZhcmV3LjJkOTEwLmpwZwpwCXRodW1iCTk1MHg1MzQjCmUJanBn/07e37410/5a9/Pluto_Farewell.jpg" caption="This image was taken as New Horizons said goodbye to Pluto. At the time the photo was taken, the spacecraft was about 1.25 million miles from Pluto. The image shows structures as small as 12 miles across." credit="NASA/JHUAPL/SWRL " alt=""]
[img src="http://rack.1.mshcdn.com/media/ZgkyMDE1LzA3LzE0LzRlL3BsdXRvY2hhcm9uLjA2MzY3LmpwZwpwCXRodW1iCTk1MHg1MzQjCmUJanBn/05198c40/5b4/pluto-charon-2.jpg" caption="Pluto (left) and its largest moon Charon (right) in false color seen by NASA's New Horizons." credit="" alt=""]
[img src="http://rack.3.mshcdn.com/media/ZgkyMDE1LzA3LzA5LzRlL3BsdXRvY2hhcm9uLjJjY2I0LmpwZwpwCXRodW1iCTEyMDB4OTYwMD4/57fc6468/a1b/pluto-charon2.jpg" caption="A view of Pluto and its largest moon Charon taken by the New Horizons probe." credit="NASA-JHUAPL-SWRI " alt=""]
"With this mission, we have visited every single planet in our solar system." - NASA Administrator Charles Bolden
Humanity's first robotic emissary to Pluto successfully phoned home and appears to be in good health after its close encounter with the dwarf planet on Tuesday.Mission controllers received a status update from NASA's New Horizons probe as expected, at about 8:53 p.m. ET Tuesday, approximately 11 hours after its close flyby with Pluto. Earlier in the day, the crew saw the first high-resolution photo from Pluto, an emotional moment scientists and engineers had waited more than nine years for.
"We have a healthy spacecraft. We've recorded data of the pluto system and we're outbound from Pluto," New Horizons mission operations manager Alice Bowman said they they received a signal from the craft."I can't express how I feel ... just like we planned it, just like we practiced. We did it. It's great."
Our understanding of Pluto has changed a lot since it was discovered in 1930.When American astronomer Clyde Tombaugh first trained the Lowell Observatory's gaze on Pluto's patch of sky, the small dwarf planet appeared as a pinprick of light in distant space. As the years went by, scientists continued to get better and better views of Pluto from powerful telescopes on Earth and in space.New Horizons had already revealed Pluto as a red world with strange dark and light patches dotting its surface. It looks completely unique within the context of the solar system, according to scientists working on the mission's team.
"Anything that's big enough to be round, we call a planet, as long as it's not a star." - NEW HORIZONS PRINCIPAL INVESTIGATOR ALAN STERN
Pluto and its moons are far more complicated than scientists bargained for when New Horizons left Earth on Jan 19, 2006.For one thing, Pluto was officially reclassified from being a planet in the solar system to the category of dwarf planet. In August 2006, just months after New Horizons launched, scientists at the International Astronomical Union's general assembly voted to "demote" Pluto from its status as a "major planet" to that of "dwarf planet." The controversial vote was met with disdain by the public and planetary scientists alike.But New Horizons Principal Investigator Alan Stern never stopped believing in Pluto's status as a planet, even if it is little.
"A planet is an object in space that is large enough to be called big, therefore a planet. What is the definition of big? Rounded by gravity," Stern said."Anything that's big enough to be round, we call a planet, as long as it's not a star."
Since New Horizons set off on its journey, researchers using the Hubble Space Telescope confirmed two more moons of Pluto — Kerberos in 2011 and Styx in 2012."There are regions on the surface [of Pluto] that have to be as dark as anything we've ever seen in the solar system," New Horizons co-investigator Marc Buie told Mashable.New Horizons might bring the little moons into clearer focus as well, beaming back new views of the small bodies, possibly revealing previously unknown aspects of their shapes, sizes and colors, says Jim Baer, the lead optical engineer for the Ralph Camera on New Horizons."We don't know what we're going to find," Baer said.Learning more about these icy bodies could help scientists piece together the cosmic history of our solar system, from how planets in the inner solar system formed to how dwarf worlds like Pluto evolved.
New Horizons launched to space on Jan. 19, 2006 for its 3-billion-mile journey to Pluto.The craft flew by multiple planets through the course of its nine-year trip, snapping a photo of Neptune and its large moon Triton.New Horizons will be traveling at about 36,000 mph during its closest approach, which will bring it about 7,800 miles from the dwarf planet’s surface, closer than any human-made spacecraft has ever been to the cosmic body.
When New Horizons makes its closest pass of Pluto, the probe will be able to pick out extreme details on the surface of the dwarf planet, according to the mission's principal investigator Alan Stern.For example, if the spacecraft were to take images of New York City at the same resolution it will get during the July Pluto flyby, scientists would be able to pull out highly recognizable features of the city."When you look at that picture of New York City, you can see the runways of LaGuardia [Airport]," Stern told Mashable in an interview. "You can see Central Park and count the ponds in Central Park. You can see wharfs on the Hudson. That's the resolution that we will have on Pluto."
"It wasn't just a random, oddball ninth planet that was different from all the others. It became the harbinger, it became the archetype of a whole new class of small planet." - NEW HORIZONS PRINCIPAL INVESTIGATOR ALAN STERN
Pluto exists in a part of space known as the Kuiper Belt — a group of icy objects outside of Neptune's orbit. By learning more about Pluto itself, scientists could unlock the secrets of a whole class of unexplored objects in our own cosmic backyard, so to speak."The Kuiper Belt was discovered in the early 90s, and all of the sudden, Pluto fit into context," Stern said."It wasn't just a random, oddball ninth planet that was different from all the others. It became the harbinger, it became the archetype of a whole new class of small planet."Icy Kuiper Belt objects are thought to be some of the oldest bodies in the solar system, so by learning more about them, we could also find out something about the evolution of every planet, including Earth, in this part of the Milky Way. It's also possible that New Horizons will get the chance to make a close pass of another object in the Kuiper Belt after it speeds past Pluto, giving scientists a better chance to see what other icy bodies in that part of space are like.
The probe should also help scientists learn more about what the tiny world's atmosphere is made out of and nail down the composition of Pluto's incredibly dark and brightly colored patches.
"There are regions on the surface [of Pluto] that have to be as dark as anything we've ever seen in the solar system," Buie said."At the same time, if you travel on Pluto, if you get in the car and drive 500 or 600 miles to the northeast of that dark region, then you're in a region that is as bright as anything we've ever seen in the solar system, yet it's all the same object."Buie has spent days staring at images of Pluto taken by the Hubble Space Telescope to create the best maps of the dark and light areas on the dwarf planet's surface through the years, but those images can't hold a candle to the way New Horizons will see that world.