Over two months after its historic flyby of Pluto, New Horizons is sending back a stream of data, helping its science teams answer outstanding questions about the dwarf planetary system and explore new mysteries surrounding Pluto\u2019s formation and its relationship with the Kuiper Belt and the solar system.<\/p>\n
\nPost-Flyby operations:<\/b><\/p>\n
It was a moment that hundreds of thousands of people around the world took part in: New Horizons\u2019 closest approach to Pluto and humanity\u2019s first visit to the dwarf planet at the inner reaches of the Kuiper Belt.<\/p>\n
But while people around the world celebrated, New Horizons\u2019 engineers and controllers were anxiously hoping that the flyby was actually happening as planned, as it would be another painstaking 13 hours before they would learn if the intrepid little probe had survived flyby and collected all the information it was tasked with gathering.<\/p>\n
![\"Z12\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2013\/12\/Z121.jpg\")
Based on the needs of the mission and design criteria for New Horizons, the probe was not in contact with Earth during any part of the flyby encounter \u2013 instead focusing all its abilities on collecting the wealth of scientific data it was instructed to.<\/p>\n
If all went to plan, New Horizons would only contact Earth once it swung past Pluto, completed its scientific collection phase, and was outbound from the dwarf planet.<\/p>\n
While close flyby occurred at 07:49:55 EDT in the U.S., with New Horizons passing just 12,500km (7,800 mi) from Pluto, New Horizons would not exit flyby mode and send its \u201cI\u2019m alive\u201d signal until 16:22 EDT.<\/p>\n
It would then take that \u201cI\u2019m alive\u201d signal 4.5 hours to reach Earth.<\/p>\n
Aerospace & Defense (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n Within NASA, John Grunsfeld, Associate Administrator for NASA\u2019s Science Mission Directorate, stated that \u201cWith the successful flyby of Pluto, we are celebrating the capstone event in a golden age of planetary exploration.<\/p>\n \u201cWhile this historic event is still unfolding \u2026 a new era of solar system exploration is just beginning.\u201d<\/p>\n For the New Horizons control team and scientists, the \u201cI\u2019m alive\u201d signal only confirmed that the probe was alive and healthy following flyby.<\/p>\n Within minutes, New Horizons\u2019 MOM (Mission Operations Manager) confirmed the most important part: New Horizons had executed all flyby commands and had gathered all the data and conducted all the scientific observations it was supposed to and was now ready to start sending all the data back to Earth.<\/p>\n For the control team and the scientists, the next phase of the mission began: the 16 month process of getting all the collected data downlinked from New Horizons to Earth.<\/p>\n The initial data:<\/p>\n Within just the first three weeks of the 16 month data download from New Horizons, mission scientists had already unlocked many of Pluto\u2019s fuzzy mysteries with startlingly clear images and radiography and spectrometry results revealing a young, still-forming surface and an atmosphere much more \u2013 and at the same time much less \u2013 than expected.<\/p>\n Since then, data has continued to come back from New Horizons, with the onslaught of data downlink \u2013 known as the intensive data downlink phase \u2013 beginning on 5 September.<\/p>\n \u201cAnd what\u2019s coming is not just the remaining 95 percent of the data that\u2019s still aboard the spacecraft \u2013 it\u2019s the best datasets, the highest-resolution images and spectra, the most important atmospheric datasets, and more. It\u2019s a treasure trove.\u201d<\/p>\n Pluto\u2019s surface:<\/p>\n Within 24 hours of the flyby, New Horizons sent back a startlingly clear and detailed image of a mountainous region on Pluto located on the edge of Tombaugh Regio (the heart-shaped surface feature).<\/p>\n \u201cThis is one of the youngest surfaces we\u2019ve ever seen in the solar system,\u201d said Jeff Moore of the New Horizons Geology, Geophysics and Imaging Team.<\/p>\n The relatively young mountains and surrounding section of Pluto\u2019s surface offered the first and surprising indications that Pluto could still be geologically active today \u2013 much like Earth continues to be geologically active.<\/p>\n Furthermore, this discovery could have widespread implications for how scientists think about geological activity and what powers it.<\/p>\n Thus, given Pluto\u2019s icy composition, there must be a different mechanism occurring on\/within Pluto to permit this continued geologic activity \u2013 a mechanism that if understood could help scientists better discern the formation processes of the outer icy worlds.<\/p>\n The frozen plains of irregularly-shaped segments 20 km (12 miles) across and bordered by shallow troughs bear striking resemblance to frozen mud cracks on Earth.<\/p>\n \u201cThis terrain is not easy to explain,\u201d said Jeff Moore. \u201cThe discovery of vast, craterless, very young plains on Pluto exceeds all pre-flyby expectations.\u201d<\/p>\n In the initial review of the frozen plains, scientists developed two working theories as to how they formed.<\/p>\n *Click here for more New Horizons Articles*<\/p>\n The first theory revolves around the idea that the frozen plains are a result of the contraction of surface materials, similar to what happens when mud dries on Earth.<\/p>\n In this manner, convection on Pluto would occur within a surface layer of frozen carbon monoxide, methane, and nitrogen, driven by the minimal warmth of Pluto\u2019s interior.<\/p>\n Several days later, new photos revealed that portions of this ice field might still be geologically moving \u2013 in much the same way that glaciers move on Earth.<\/p>\n The area of the ice field is composed primarily of nitrogen, carbon monoxide, and methane ices.<\/p>\n According to Bill McKinnon, deputy leader of the New Horizons Geology, Geophysics and Imaging team, \u201cAt Pluto\u2019s temperatures of minus 390 degrees Fahrenheit, these ices can flow like a glacier.\u201d<\/p>\n Following commencement of the intensive data downlink phase, shock regarding Pluto\u2019s wide-ranging and diverse surface features continued to grow.<\/p>\n \u201cPluto is showing us a diversity of landforms and complexity of processes that rival anything we\u2019ve seen in the solar system,\u201d said Alan Stern. \u201cIf an artist had painted this Pluto before our flyby, I probably would have called it over the top \u2013 but that\u2019s what is actually there.\u201d<\/p>\n Of particular note to the science teams in the recent images returned from New Horizons is a field of what appears to be dark, wind-blown dunes.<\/p>\n \u201cSeeing dunes on Pluto \u2013 if that is what they are \u2013 would be completely wild, because Pluto\u2019s atmosphere today is so thin,\u201d said Bill McKinnon.<\/p>\n \u201cEither Pluto had a thicker atmosphere in the past, or some process we haven\u2019t figured out is at work. It\u2019s a head-scratcher.\u201d<\/p>\n Pluto\u2019s atmosphere:<\/p>\n Pluto\u2019s surface is not the only part of the dwarf planet that has so far offered up some interesting surprises for New Horizons\u2019 teams.<\/p>\n Pluto\u2019s atmosphere had previously only been observed at altitudes no higher than 270 km (170 miles) \u2013 and as Pluto is currently moving away from the sun in its orbital path, its atmosphere is thought to be in the process of freezing to its surface.<\/p>\n According to New Horizons scientist Andrew Steffl, \u201cThe data we have now show that Pluto\u2019s atmosphere rises higher above its surface, in relative terms, than does the Earth\u2019s.\u201d<\/p>\n The initial information on Pluto\u2019s atmosphere came from the Alice instrument that used spectrography during a carefully designed alignment of the Sun, Pluto, and New Horizons an hour after the craft\u2019s closest approach to the dwarf planet.<\/p>\n The initial Alice information further revealed that Pluto\u2019s atmosphere matches neither of the two plausible models developed prior to the flyby.<\/p>\n Thus far, Alice information has revealed that Pluto\u2019s atmosphere is closer to the \u201cstagnant\u201d model (a large abundance of hydrocarbons) than to the \u201cturbulent\u201d model (low amount of sun-light absorbing hydrocarbons).<\/p>\n The complete Alice spectrograph was sent from New Horizons in August and will allow scientists to make a more conclusive study of and determination about Pluto\u2019s atmosphere.<\/p>\n Meanwhile, as New Horizons passed behind Pluto and began its outbound journey from the dwarf planet, the probe detected an area of cold, dense, ionized gas tens of thousands of miles beyond Pluto.<\/p>\n Initial data points showed a trail of ionized escaped nitrogen extending 77,000 km (48,000 miles) to 109,000 km (68,000 miles) \u201cdownstream\u201d of Pluto.<\/p>\n While this ionized trail confirms that Pluto is losing atmosphere to the solar wind, the specific rate of loss has not yet been determined.<\/p>\n But Pluto\u2019s complex atmosphere thus far sampled and returned by New Horizons extends beyond hydrocarbons and how much of the atmosphere is escaping to space.<\/p>\n The surface pressure created by Pluto\u2019s atmosphere has also given scientists a shock: It\u2019s far lower than compared to previous observations.<\/p>\n While a lower surface pressure than that of Earth is not surprising given Pluto\u2019s smaller size and smaller atmosphere, this measurement is only about half the calculated surface pressure from just a few years ago.<\/p>\n \u201cFor the first time, we have ground truth, measuring the surface pressure at Pluto, giving us an invaluable perspective on conditions at the surface of the planet,\u201d said New Horizons researcher Ivan Linscott.<\/p>\n \u201cThis crucial measurement may be telling us that Pluto is undergoing long-anticipated global change.\u201d<\/p>\n That long anticipated change is the freezing of Pluto\u2019s atmosphere to the surface of the dwarf planet as it moves farther from the Sun in its prolonged orbit.<\/p>\n Since this change occurs relatively quickly during Pluto\u2019s orbit, the almost half of expected measurement of Pluto\u2019s surface pressure could indicate that about half of Pluto\u2019s atmosphere has already frozen to its surface since the last measurements were derived in the early 2010s.<\/p>\n New downlinked images from New Horizons have revealed that Pluto\u2019s global atmospheric haze has many more layers than scientists realized.<\/p>\n Moreover, these layers create a twilight effect that softly illuminates nightside terrain near sunset.<\/p>\n \u201cThis bonus twilight view is a wonderful gift that Pluto has handed to us,\u201d said John Spencer, a GGI deputy lead. \u201cNow we can study geology in terrain that we never expected to see.\u201d<\/p>\n What the data means for Pluto\u2019s status: <\/p>\n While many people continue to protest the International Astronomical Union\u2019s (IAU\u2019s) official classification of Pluto as a dwarf planet, data from New Horizons \u2013 as much as some would hope \u2013 is unlikely to change Pluto\u2019s status.<\/p>\n However, one thing that New Horizons did finally confirm with finality is Pluto\u2019s size.<\/p>\n With a diameter of 2,372 km (1,474 mi), Pluto is the largest of the five dwarf planets and the ninth largest object known to be in direct orbit of the Sun.<\/p>\n Furthermore, by volume, Pluto is the largest known trans-Neptunian object; however, by mass, it is the second most-massive dwarf planet after Eris (also in the Kuiper Belt).<\/p>\n However, and most importantly, Pluto\u2019s classification neither changes the nature of the information that New Horizons will return nor does it change Pluto\u2019s importance within the larger picture of the solar system.<\/p>\n Understanding Pluto and its complex geology and atmosphere will help scientists gain a clearer understanding of how terrestrial bodies within the Kuiper Belt formed\/are forming as well as the clues they might hold as to the formation of the solar system (both in general and in terms of how the four terrestrial planets formed billions of years ago).<\/p>\n (Images via JPL\/NASA)<\/p>\n","protected":false},"excerpt":{"rendered":" Over two months after its historic flyby of Pluto, New Horizons is sending back a stream of data, helping its science teams answer outstanding questions about the dwarf planetary system and explore new mysteries surrounding Pluto\u2019s formation and its relationship with the Kuiper Belt and the solar system. Post-Flyby operations: It was a moment that hundreds of thousands of people around the […]<\/p>\n","protected":false},"author":1,"featured_media":30165,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[2174,2848],"class_list":["post-39243","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","tag-new-horizons","tag-pluto"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/39243"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=39243"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/39243\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media\/30165"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=39243"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=39243"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=39243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"2015-09-17-200822\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-200822-350x238.jpg\")
At 20:52:37 EDT, after a stressful final minutes of waiting, the \u201cI\u2019m alive\u201d signal reached Earth to the jubilation and cheers of New Horizons\u2019 engineers and scientists \u2013 and also to the elation of the two children of Clyde Tombaugh (the person who discovered Pluto in 1930).<\/p>\nSee Also<\/h4>\n
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![\"2015-09-17-201022\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-201022-350x252.jpg\")
According to Alan Stern, New Horizons Principal Investigator, \u201cThis is what we came for \u2013 these images, spectra and other data types that are going to help us understand the origin and the evolution of the Pluto system for the first time.<\/p>\n![\"2015-09-17-201123\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-201123-350x279.jpg\")
Located near the equatorial region of Pluto, the icy mountain range, with peaks as high as 3,500 m (11,000 ft), likely formed no more than 100 million years ago \u2013 relatively young compared to the 4.56 billion year age of the solar system.<\/p>\n![\"2015-09-17-201250\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-201250-350x229.jpg\")
Unlike the giant planets\u2019 icy moons (e.g. Enceladus) which are still geologically active because of tidal heating created during those icy moons\u2019 orbits of their much larger parents, Pluto\u2019s current or recent geological activity cannot be explained by tidal heating from a larger body (in the way Enceladus\u2019 can) because there is no larger body near Pluto.<\/p>\n![\"2015-09-17-201406\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-201406-350x255.jpg\")
Moreover, within days, new images from New Horizons revealed further stretches of geologically young (no older than 100 million years) frozen plain features on the center-east region of Tombaugh Regio.<\/p>\n![\"2015-09-17-203110\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-203110-350x234.jpg\")
The second working theory is that the frozen plains are a product of convection, similar to wax rising in a lava lamp.<\/p>\n![\"2015-09-17-202212\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-202212-350x226.jpg\")
Furthermore, the images caused John Spencer, mission co-investigator, to state that \u201cWe\u2019ve only seen surfaces like this on active worlds like Earth and Mars\u201d \u2013 thus adding to the mounting evidence that Pluto is still a geologically active world.<\/p>\n![\"2015-09-17-202509\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-202509-350x319.jpg\")
On the second day of data download from New Horizons, images revealed that Pluto\u2019s atmosphere extends as far as 1,600 km (1,000 miles) above the surface of the dwarf planet.<\/p>\n![\"2015-09-17-202549\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-202549-350x277.jpg\")
Using a created solar occultation (when a body passes directly between an observation point and the Sun and completely blocks the view of the Sun from the observation point), New Horizons\u2019 Alice spectrograph viewed Pluto\u2019s atmosphere as it was backlit by the Sun.<\/p>\n![\"2015-09-17-202634\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-202634-350x280.jpg\")
Detected by the SWAP (Solar Wind Around Pluto) instrument, New Horizons captured part of the extent of the loss of Pluto\u2019s atmosphere to the solar wind \u2013 one of the mission\u2019s primary objectives.<\/p>\n![\"2015-09-17-202750\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-202750-350x284.jpg\")
Obtained by the Rex radio instrument, Pluto\u2019s surface atmospheric pressure is approximately 1\/100-thousandth of the pressure at Earth sea-level.<\/p>\n![\"2015-09-17-201808\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-201808-350x253.jpg\")
Furthermore, in September, scientists learned even more about Pluto\u2019s multi-layered atmosphere.<\/p>\n![\"2015-09-17-201906\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-201906-350x209.jpg\")
While people have even gone to the length of starting a petition to demand the reclassification of Pluto back to planet status because of the New Horizons flyby, no data returned by New Horizons could change the fact that Pluto has not cleared its neighboring region of planetesimals, the third of three mandatory qualifications for planethood under the current IAU definition.<\/p>\n![\"2015-09-17-202006\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2015\/09\/2015-09-17-202006-350x266.jpg\")
The confirmation of Pluto\u2019s size and volume has led some to confer the affectionate title of King of the Dwarfs to Pluto.<\/p>\n