{"id":16174,"date":"2015-07-18T17:20:11","date_gmt":"2015-07-18T09:20:11","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/scientists-find-signs-of-potential-geysers-on-pluto\/"},"modified":"2015-07-18T17:20:11","modified_gmt":"2015-07-18T09:20:11","slug":"scientists-find-signs-of-potential-geysers-on-pluto","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/scientists-find-signs-of-potential-geysers-on-pluto\/","title":{"rendered":"Scientists find signs of potential geysers on Pluto"},"content":{"rendered":"
\"This
This week\u2019s New Horizons flyby of Pluto revealed unexpected terrain, such as these blocky patches of ice at a region dubbed Sputnik Planum. New Horizons\u2019 LORRI camera took this image from a distance of 48,000 miles (77,00 kilometers) on July 14. The resolution is about 1 kilometer (0.6 miles). The large pixelated areas are caused by the compression of the image. A later version of the image will be downlinked without noise. Credit: NASA\/JHUAPL\/SWRI<\/figcaption><\/figure>\n

New results from NASA\u2019s New Horizons mission, which zipped about 7,700 miles from faraway Pluto on Tuesday, show puzzling icy landforms covered in frozen carbon monoxide and mysterious dark smudges, which may be evidence for plumes erupting from Pluto\u2019s warmer interior, scientists said Friday.<\/p>\n

\u201cI\u2019m a little biased, but I think the solar system saved the best for last,\u201d said Alan Stern, the mission\u2019s principal investigator from the Southwest Research Institute.<\/p>\n

Imagery from the probe\u2019s telescopic camera captured icy terrain broken into shapes, with vein-like features, some filled with unknown dark material, separating the frozen blocks across a region about the size of the Netherlands.<\/p>\n

\u201cI\u2019m still having to remind myself to take deep breaths,\u201d said Jeffrey Moore, a New Horizons co-investigator from NASA\u2019s Ames Research Center in California. \u201cThe landscape is just astoundingly amazing.\u201d<\/p>\n

The images from New Horizons, which was more than 2 million miles outbound from Pluto on Friday, were culled from a small dataset downlinked to Earth since Tuesday\u2019s flyby. Only about 1 gigabit of the encounter\u2019s total data haul of around 50 gigabits has been downlinked to Earth, according to Stern.<\/p>\n

While the data is just a sampling of what is to come, the results so far are rich.<\/p>\n

\u201cThe surface is broken up into \u2026 irregularly-shaped segments that are roughly 12 to 20 miles across,\u201d Moore said. \u201cThey are bordered by what appear to be shallow troughs. Some of these troughs have some darker material \u2026 I don\u2019t know if that\u2019s material that\u2019s collected there or erupted there. I don\u2019t know.\u201d<\/p>\n

The craterless ice field revealed Friday has been dubbed Sputnik Planum. It is part of a larger bright, heart-shaped feature on Pluto informally named Tombaugh Regio after Clyde Tombaugh, who discovered the dwarf planet lurking at the solar system\u2019s frontier in 1930.<\/p>\n

Sputnik Planum is part of a swath of Pluto detected by New Horizons to be made of frozen carbon monoxide. Earth-based measurements found carbon monoxide ice on Pluto in 1992, but New Horizons pinpointed its location.<\/p>\n

The initial data from New Horizons, which made the first ever visit to Pluto, does not tell whether the carbon monoxide detection is from a thin layer covering another type of ice, or a more significant part of a mixture of methane and nitrogen ice scientists say dominate Pluto\u2019s crust.<\/p>\n

\"The
The Ralph instrument on New Horizons has discovered the signature of frozen carbon monoxide concentrated in the western half of Pluto\u2019s bright heart-shaped feature, informally named Tombaugh Regio. Credit: NASA\/JHUAPL\/SWRI<\/figcaption><\/figure>\n

\u201cYou only need a centimeter (0.4 inches) or something to produce an absorption of that depth,\u201d said Will Grundy, head of the composition science team on New Horizons. \u201cSo we know that there\u2019s a lid that includes a lot of carbon monoxide, but how that interacts is potentially quite subtle.\u201d<\/p>\n

At Pluto\u2019s orbit 3 billion miles from the sun, the temperature in the ice field is around minus 400 degrees Fahrenheit.<\/p>\n

\u201cJudging from the absence of impact craters, it\u2019s clear that Sputnik Planum couldn\u2019t possibly be more than 100 million years old, and possibly is still being shaped to this day by geologic processes,\u201d Moore said. \u201cThis could be only a week old for all we know.\u201d<\/p>\n

The ice blocks at Sputnik Planum, which Moore calls polygons, could be produced in several ways.<\/p>\n

\u201cOne possibility, out of many, is that the polygons are signs of convection occuring within the surface layer of carbon monoxide, methane and nitrogen ice driven by the modest heat from the interior of Pluto itself, creating the same sorts of patterns you see when you look at the surface of a boiling pot of oatmeal, or like the blobs in a lava lamp,\u201d Moore said.<\/p>\n

\u201cAlternatively, these polygons could be analogous to mud cracks, and could be caused by contraction of surface materials,\u201d Moore said.<\/p>\n

He said he lends more weight to the theory that the icy plain was formed by heat bubbling up from underneath, but thermal contraction, which is responsible for polygon features at the icy northern latitudes of Mars, could also be the root.<\/p>\n

The youthful appearance of Pluto\u2019s frozen plains, coupled with the discovery of huge 11,000-foot-tall mountains announced Wednesday, point to tectonic activity on the frozen body, a surprise to many scientists.<\/p>\n

Other parts of Pluto have impact craters, evidence that those surfaces likely formed billions of years ago.<\/p>\n

\u201cSome of the craters appear partially destroyed, perhaps by erosion, and there are also hints of parts of Pluto\u2019s crust that have been fractured,\u201d Moore said. \u201cThat probably indicates some form of tectonics. Now that we\u2019ve seen mountains, I think there are pretty obviously mountain-building forces operating on Pluto.\u201d<\/p>\n

Exactly what drives Pluto\u2019s resurfacing is unclear. Scientists thought the faraway icy dwarf was far too small to support geologic activity in modern times, and Pluto does not orbit a massive mother planet.<\/p>\n

Researchers surmised the gravity from a huge nearby planet may be to power geologic activity on small bodies in the outer solar system. Scientists believe the pull of gravity from planets like Jupiter, Saturn, Uranus and Neptune stretch the rock in their moons, softening the interiors of the icy satellites and triggering melting, volcanoes and geysers.<\/p>\n

The icy plains of Sputnik Planum are dotted with hills and small pits. Moore said stereo imagery to be sent back to Earth in the coming weeks will tell scientists the size of the hills, and high-fidelity, uncompressed imagery will confirm the pits are not actually image artifacts.<\/p>\n

The origin of the hills is still up for debate, but either theory is mind-boggling, Moore said.<\/p>\n

\"Scientists
Scientists created this composite of Pluto and its largest moon Charon using the latest full-frame images of the objects from New Horizons on approach. The relative reflectivity, size, separation, and orientations of Pluto and Charon are approximated in this composite image, and they are shown in approximate true color. Credit: NASA\/JHUAPL\/SWRI<\/figcaption><\/figure>\n

\u201cWe suspect the hills may have either been pushed up from underneath along the cracks, but alternatively, a completely different explanation is that they are erosion-resistant knobs that are standing out as the surface is being massively eroded and lowered,\u201d Moore said. \u201cWe don\u2019t know which of those two explanations is correct.\u201d<\/p>\n

Moore calls the competing theories the \u201cbottom up\u201d and the \u201ctop down\u201d hypotheses.<\/p>\n

\u201cI like the scenario of it upwelling from below, but I dont think we\u2019re anywhere near proving that\u2019s what\u2019s happening,\u201d Grundy said.<\/p>\n

Either way, evidence is mounting for Pluto being an evolving world.<\/p>\n

Besides the intriguing mystery material lining the borders of some of Sputnik Planum\u2019s frozen blocks, which could be a sign of eruptions from underneath, Moore highlighted another finding that may point to the presence of geysers or cryo-volcanism on Pluto.<\/p>\n

A line of dark smudges to the northwest of Sputnik Planum has caught the attention of scientists.<\/p>\n

On Earth and Mars, such features are often caused by material deposited by prevailing winds against hills and other protrusions.<\/p>\n

While careful to tamp down expectations, Moore said one \u201cspeculative\u201d source for the smudges could be cryo-volcanism.<\/p>\n

\u201cThey may be plume deposits associated with glaciers like those seen on Neptune\u2019s icy satellite Triton. The plumes themselves, if they exist on Pluto, have not been spotted yet,\u201d Moore said. \u201cBut we will be looking for them in images yet to be received from the spacecraft.\u201d<\/p>\n

On Triton, one of Pluto\u2019s closest known analogs in the outer solar system, such markings are left by volcanoes periodically throwing subsurface material into the sky.<\/p>\n

Moore cautioned he wants to see \u201cunambiguous evidence\u201d for geysers and plumes before declaring Pluto has modern-day eruptions.<\/p>\n

What is clear \u2014 and surprising \u2014 is Pluto is a living planet, with forces reshaping its topography in recent geologic timescales.<\/p>\n

\u201cPeople have for many years, since the 1970s at least, wondered whether these very evolved young terrains you see on the icy moons of the gas giants were made that way because of the process we call tidal heating, where the moons interact with themselves and with the body they\u2019re orbiting around to basicaly heat up their interiors through friction,\u201d Moore said. \u201cPeople see (Jupiter\u2019s moon) Io\u2019s volvanoes erupting, (and) they attribute it to this process called tidal torque heating.\u201d<\/p>\n

\"Not
Not Pluto, but Triton! NASA\u2019s Voyager 2 spacecraft flew by Neptune and its largest moon Triton in August 1989. Triton is believed to be a large Kuiper Belt Object like Pluto, which was captured into orbit by Neptune. Credit: NASA\/JPL\/USGS<\/figcaption><\/figure>\n

\u201cThe question was could icy worlds minding their own business \u2014 not orbiting some giant planet \u2014 also be geologically active, and the answer is obviously yes,\u201d Moore said. \u201cPluto is every bit as geologically active as any place we\u2019ve seen in the solar system. This really answers a fundamental question about are icy worlds able to do their thing in their own right, or are they dependent upon the help of the big planets they orbit around.\u201d<\/p>\n

New Horizons scientists announced other findings in press briefing Friday at NASA Headquarters in Washington.<\/p>\n

Observations of Pluto\u2019s tenuous atmosphere, about one hundred thousandth the thickness of Earth\u2019s, have also revealed a surprising uniformity and a thin veneer of gas mostly packed within a mile of the icy world\u2019s surface.<\/p>\n

New Horizons also detected Pluto\u2019s atmosphere extending out to 1,000 miles as particles spread out due to the dwarf planet\u2019s low gravity. Before the encounter, Earth-based views only showed the atmosphere out to 170 miles.<\/p>\n

Randy Gladstone, head of the New Horizons atmospheric science team, said spectroscopic measurements made by the probe\u2019s Alice instrument show the atmosphere to be mostly stagnant.<\/p>\n

\u201cWe still don\u2019t have a good measure of the lowest atmosphere, where it\u2019s very complicated,\u201d Gladstone said. \u201cWe think all the atmosphere on Pluto is sort of compressed into a very thin layer near the surface, where the winds could be up to a few meters per second (5 to 8 mph) easily.\u201d<\/p>\n

The frigid, tenuous atmosphere is mostly nitrogen \u2014 the primary constituent of Earth\u2019s atmosphere \u2014 and pressures at Pluto\u2019s surface are roughly equivalent to conditions about 50 miles above Earth, according to Gladstone.<\/p>\n

Better data on the atmosphere is coming down in the coming days.<\/p>\n

NASA blasted 80 kilowatts of radio waves toward Pluto as New Horizons passed behind the far side of the distant dwarf, and a receiver aboard the spacecraft measured how the signals were distorted in an attempt to learn about the atmosphere\u2019s profile.<\/p>\n

And the craft\u2019s long-range camera snapped photos of Pluto\u2019s sunlit crescent as it sped away at nearly 31,000 mph in search of haze and clouds. Those images should be back on Earth next week, Gladstone said.<\/p>\n

\"A
A diagram of Pluto\u2019s ionized tail. Credit: NASA\/JHUAPL\/SWRI<\/figcaption><\/figure>\n

Scientists knew Pluto\u2019s atmospheric particles were escaping into space, and New Horizons confirmed that the atmosphere is slowly disintegrating.<\/p>\n

All the data is not in, but scientists suspected before the flyby that Pluto lacks a magnetosphere, which is driven on other planets by internal dynamos. Instead, Pluto\u2019s escaping atmosphere creates a bubble encompassing all five of the world\u2019s moons, and the solar wind smashes into atmospheric particles on the side of Pluto facing the sun.<\/p>\n

On the downwind side, Pluto has a tail of ionized gas at least tens of thousands of miles long, New Horizons has observed.<\/p>\n

\u201cWhat we see behind Pluto is a tail, an ion tail, of this ionized escaping atmosphere that\u2019s been pulled away and carried away in the solar wind,\u201d said Fran Bagenal, a New Horizons co-investigator from the University of Colorado at Boulder.<\/p>\n

Information from the flyby still stored aboard New Horizons will help researchers quantify the rate at which the atmosphere is escaping.<\/p>\n

\u201cWhat we think it is, based on models and a pretty good guess, is about 500 tons per hour of material that is escaping,\u201d Bagenal said. \u201cFor comparison, we know that the escaping atmosphere from Mars, which has been studied by NASA\u2019s MAVEN mission, is about one ton per hour. This is substantially more because of the weaker gravity on Pluto.\u201d<\/p>\n

With so much of Pluto\u2019s nitrogen-rich atmosphere clearing out, scientists are asking what replenishes it during the dwarf planet\u2019s 248-year orbit around the sun.<\/p>\n

The results so far are just the \u201ctip of the iceberg,\u201d said Jim Green, director of NASA\u2019s planetary science division.<\/p>\n

\u201cFor nearly 10 years, the New Horizons team was always talking about each day we\u2019re closer to Pluto,\u201d Green said. \u201cNow each day we\u2019re farther away from Pluto.\u201d<\/p>\n

It will take 16 months for all the data from the flyby to flow back to Earth at a few kilobits per second. New Horizons is initially sending down a first look with compressed images prone to artifacts. The \u201clossless\u201d data will come down later.<\/p>\n

\u201cIt\u2019s important to remember that it\u2019s during this time that we\u2019re going to be able to obtain the data from the flyby,\u201d Green said. \u201cRight now, we\u2019ve only received 1 to 2 percent of that data on the ground. By next week, we\u2019ll have perhaps as much as 5 to 6 percent.\u201d<\/p>\n

Beginning later this month through September, New Horizons will halt the downlinking of high-resolution imagery to send down data from other instruments.<\/p>\n

Email the author.<\/i><\/b><\/p>\n

Follow Stephen Clark on Twitter: @StephenClark1.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

This week\u2019s New Horizons flyby of Pluto revealed unexpected terrain, such as these blocky patches of ice at a region dubbed Sputnik Planum. New Horizons\u2019 LORRI camera took this image from a distance of 48,000 miles (77,00 kilometers) on July 14. The resolution is about 1 kilometer (0.6 miles). The large pixelated areas are caused […]<\/p>\n","protected":false},"author":1,"featured_media":0,"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-16174","post","type-post","status-publish","format-standard","hentry","category-news","tag-new-horizons","tag-pluto"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16174"}],"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=16174"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/16174\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=16174"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=16174"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=16174"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}