25 amazing discoveries from NASA's mission to Pluto
Meteorologist/Science Writer
Friday, July 24, 2015, 3:26 PM - NASA's New Horizons became the first spacecraft to fly by Pluto and its moons and has been releasing new images and discoveries from the planet ever since the July 14 milestone.
The latest briefing, revealing even more new images and information from the New Horizons team took place on Friday, July 24, at 2 p.m. EDT, and you can keep up on the mission briefings and announcements here.
Only scraping the thinnest surface of 16 months worth of data that will slowly trickle down to Earth from the spacecraft from here on, read below for The Weather Network's updating list of the coolest things we've seen and learned so far:
1. Pluto dazzles in hi-res true colour and false colour
This latest images of Pluto, released on July 24, 2015, showing the dwarf planet in amazing high resolution true colour and in false colour to bring out more details. Credit: NASA/JHUAPL/SWRI
According to NASA:
Four images from New Horizons’ Long Range Reconnaissance Imager (LORRI) were combined with color data from the Ralph instrument to create this sharper global view of Pluto. (The lower right edge of Pluto in this view currently lacks high-resolution color coverage.) The images, taken when the spacecraft was 280,000 miles (450,000 kilometers) away from Pluto, show features as small as 1.4 miles (2.2 kilometers). That’s twice the resolution of the single-image view captured on July 13 and revealed at the approximate time of New Horizons’ July 14 closest approach.
New Horizons scientists use enhanced color images to detect differences in the composition and texture of Pluto’s surface. When close-up images are combined with color data from the Ralph instrument, it paints a new and surprising portrait of the dwarf planet. The “heart of the heart,” Sputnik Planum, is suggestive of a source region of ices. The two bluish-white “lobes” that extend to the southwest and northeast of the “heart” may represent exotic ices being transported away from Sputnik Planum.
2. A view of hazy Pluto in the rear-view mirror
NASA’s New Horizons spacecraft snapped this image once it had passed Pluto, looking back at sunlight highlighting the dwarf planet's thin atmosphere. Credit: NASA/JHUAPL/SWRI
According to NASA:
Just seven hours after closest approach, New Horizons aimed its Long Range Reconnaissance Imager (LORRI) back at Pluto, capturing sunlight streaming through the atmosphere and revealing hazes as high as 80 miles (130 kilometers) above Pluto’s surface. A preliminary analysis of the image shows two distinct layers of haze –one about 50 miles (80 kilometers) above the surface and the other at an altitude of about 30 miles (50 kilometers).
“My jaw was on the ground when I saw this first image of an alien atmosphere in the Kuiper Belt,” said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute (SwRI), Boulder, Colorado. “It reminds us that exploration brings us more than just incredible discoveries--it brings incredible beauty.”
A closeup view of Pluto's atmosphere. Inset shows haze layers up to 80 km above the surface. Credit: NASA/JHUAPL/SWRI
According to NASA:
"The hazes detected in this image are a key element in creating the complex hydrocarbon compounds that give Pluto’s surface its reddish hue," said Michael Summers, New Horizons co-investigator at George Mason University in Fairfax, Virginia.
Models suggest the hazes form when ultraviolet sunlight breaks up methane gas particles - a simple hydrocarbon in Pluto’s atmosphere. The breakdown of methane triggers the buildup of more complex hydrocarbon gases, such as ethylene and acetylene, which also were discovered in Pluto’s atmosphere by New Horizons. As these hydrocarbons fall to the lower, colder parts of the atmosphere, they condense into ice particles that create the hazes. Ultraviolent sunlight chemically converts hazes into tholins, the dark hydrocarbons that color Pluto’s surface.
Scientists previously had calculated temperatures would be too warm for hazes to form at altitudes higher than 20 miles (30 kilometers) above Pluto’s surface.
"We’re going to need some new ideas to figure out what’s going on," said Summers.
3. Pluto's surface reveals flowing ice!
In the northern region of Pluto’s Sputnik Planum, the patterns of light and dark material suggest that exotic ices have flowed around obstacles and into depressions, much like is seen with Earth's glaciers. Credit: NASA/JHUAPL/SWRI
4. Regions of the surface are amazingly complex
This region of Sputnik Planum shows the transition between newer surface in The Heart and older, cratered surface of the Cthulhu Regio. Credit: NASA/JHUAPL/SWRI
The newly-discovered range of mountains rises one mile (1.6 kilometers) above the surrounding plains, similar to the height of the Appalachian Mountains in the United States. These peaks have been informally named Hillary Montes (Hillary Mountains) for Sir Edmund Hillary, who first summited Mount Everest with Tenzing Norgay in 1953.
“For many years, we referred to Pluto as the Everest of planetary exploration,” said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute, Boulder, Colorado. “It’s fitting that the two climbers who first summited Earth’s highest mountain, Edmund Hillary and Tenzing Norgay, now have their names on this new Everest.”
5. A second mountain range in Pluto's Heart
Pluto’s icy mountains have company. NASA’s New Horizons mission has discovered a new, apparently less lofty mountain range on the lower-left edge of Pluto’s best known feature. Credit: NASA/JHUAPL/SWRI
According to NASA:
This newest image further illustrates the remarkably well-defined topography along the western edge of Tombaugh Regio.
"There is a pronounced difference in texture between the younger, frozen plains to the east and the dark, heavily-cratered terrain to the west," said Jeff Moore, leader of the New Horizons Geology, Geophysics and Imaging Team (GGI) at NASA’s Ames Research Center in Moffett Field, California. "There’s a complex interaction going on between the bright and the dark materials that we’re still trying to understand."
While Sputnik Planum is believed to be relatively young in geological terms – perhaps less than 100 million years old - the darker region probably dates back billions of years. Moore notes that the bright, sediment-like material appears to be filling in old craters (for example, the bright circular feature to the lower left of center).
6. Closeup, colour views of Pluto's moons, Nix and Hydra
Close-up, colour, enhanced images of Pluto's largest moons, after Charon. Credit: NASA/JHUAPL/SWRI
According to NASA:
New Horizons’ first color image of Pluto’s moon Nix, in which colors have been enhanced, reveals an intriguing region on the jelly bean-shaped satellite, which is estimated to be 26 miles (42 kilometers) long and 22 miles (36 kilometers) wide.
Although the overall surface color of Nix is neutral grey in the image, the newfound region has a distinct red tint. Hints of a bull’s-eye pattern lead scientists to speculate that the reddish region is a crater. "Additional compositional data has already been taken of Nix, but is not yet downlinked. It will tell us why this region is redder than its surroundings," said mission scientist Carly Howett, Southwest Research Institute, Boulder, Colorado. She added, "This observation is so tantalizing, I’m finding it hard to be patient for more Nix data to be downlinked."
Meanwhile, the sharpest image yet received from New Horizons of Pluto’s satellite Hydra shows that its irregular shape resembles the state of Michigan. The new image was made by the Long Range Reconnaissance Imager (LORRI) on July 14, 2015 from a distance of 143,000 miles (231,000 kilometers), and shows features as small as 0.7 miles (1.2 kilometers) across. There appear to be at least two large craters, one of which is mostly in shadow. The upper portion looks darker than the rest of Hydra, suggesting a possible difference in surface composition. From this image, mission scientists have estimated that Hydra is 34 miles (55 kilometers) long and 25 miles (40 kilometers) wide.
In ranking Pluto's moons, they present a different order of the list depending on whether you go by relative size or distance from Pluto. From innermost to outermost, they are ranked Charon, Styx, Nix, Kerberos, and Hydra, while by largest to smallest they are ranked Charon, Hydra, Nix, Kerberos and Styx.
Kerberos and Styx are, presumably, in the New Horizons data somewhere, however it could be some time before we get our first look at these tiny objects.
7. The portrait of a binary planet
The best composite of both Pluto and Charon together, as New Horizons would have seen it on approach. Although the two images were captured separately - Pluto on July 13 and Charon on July 14 - they have been positioned here and processed to present them as the correct size, at the correct relative distance from their orbital barycenter, and with the right colour to show what the pair really looks like.
8. Which way do the winds blow on Pluto?
Wind streaks? Credit: NASA/JHUAPL/SWRI
Although the science team has not yet found plumes on Pluto's surface, but what they're seeing here in this image looks very much like wind streaks - material being deposited or eroded away by wind.
However, according to the team, the sizes of these streaks in the image are roughly the same size as the errors that crop up in the images due to data compression. Thus, further data downloads are needed to confirm if they are real or simply image artifacts.
9. Shining light on Pluto's atmosphere
After New Horizons made its flyby, it pivoted to look back towards Pluto and Charon, to watch as the Sun set through Pluto's atmosphere (and Charon's, if it possesses one). The video below shows an artist's impression of what that would look like from New Horizons' perspective.
The graph to the right of the animation gives two different scenarios the science team modeled - the blue line represents what they expect to see if Pluto's atmosphere is more dynamic, red is if it is more stagnant. The data it collected shows that it follows neither case, but it is much closer to the stagnant scenario. This result would seem to indicate that the atmosphere contains a significant amount of hydrocarbons, similar (perhaps) to Titan's atmosphere.
This graph shows how the signal received by New Horizons from the Goldstone Deep Space Communication Complex was altered by Pluto's atmosphere. Credit: NASA/JHUAPL/SWRI
At the same time, the Goldstone antennas of NASA's Deep Space Network were sending signals towards Pluto, which New Horizons would pick up as it passed "behind" Pluto and Charon, to "see" that signal through Pluto's atmosphere. The above graph shows how that signal was diminished as the spacecraft passed into Pluto's shadow and then strengthened again as it emerged on the other side. This gives further clues about the structure of Pluto's atmosphere.
10. The Icy, Frozen Plains of Pluto
A closeup of a region in the heart-shaped Tombaugh Regio - named after Pluto's discoverer - shows the complex terrain of Sputnik Planum. Credit: NASA/JHUAPL/SWRI
Next to the mountainous region revealed on Wednesday is the region above, showing just how contrasted different areas of Pluto's surface can be.
"This terrain is not easy to explain," said Jeff Moore, leader of the New Horizons Geology, Geophysics and Imaging Team (GGI), in a NASA statement. "The discovery of vast, craterless, very young plains on Pluto exceeds all pre-flyby expectations."
According to the NASA press release:
This fascinating icy plains region - resembling frozen mud cracks on Earth - has been informally named “Sputnik Planum” (Sputnik Plain) after the Earth’s first artificial satellite. It has a broken surface of irregularly-shaped segments, roughly 12 miles (20 kilometers) across, bordered by what appear to be shallow troughs. Some of these troughs have darker material within them, while others are traced by clumps of hills that appear to rise above the surrounding terrain. Elsewhere, the surface appears to be etched by fields of small pits that may have formed by a process called sublimation, in which ice turns directly from solid to gas, just as dry ice does on Earth.
Scientists have two working theories as to how these segments were formed. The irregular shapes may be the result of the contraction of surface materials, similar to what happens when mud dries. Alternatively, they may be a product of convection, similar to wax rising in a lava lamp. On Pluto, convection would occur within a surface layer of frozen carbon monoxide, methane and nitrogen, driven by the scant warmth of Pluto’s interior.
The hills seen in this view may be formations pushed up from below, or they could be erosion-resistant formations that are being exposed as the icescape around them is eroded away.
11. A flyover of Pluto's mountains
According to NASA:
This simulated flyover of Pluto’s Norgay Montes (Norgay Mountains) and Sputnik Planum (Sputnik Plain) was created from New Horizons closest-approach images. Norgay Montes have been informally named for Tenzing Norgay, one of the first two humans to reach the summit of Mount Everest. Sputnik Planum is informally named for Earth’s first artificial satellite. The images were acquired by the Long Range Reconnaissance Imager (LORRI) on July 14 from a distance of 48,000 miles (77,000 kilometers). Features as small as a half-mile (1 kilometer) across are visible. Credit: NASA/JHUAPL/SWRI
12. Closeup of Sputnik Planum, in Pluto's frozen heart
According to NASA:
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.
13. Pluto's frozen heart has a carbon monoxide core
These concentric lines in Pluto's "heart" - named Tombaugh Regio after dwarf planet's discoverer - outline a region that's rich in carbon monoxide. Credit: NASA-JHUAPL-SWRI
According to NASA:
Peering closely at the “heart of Pluto,” in the western half of what mission scientists have informally named Tombaugh Regio (Tombaugh Region), New Horizons’ Ralph instrument revealed evidence of carbon monoxide ice. The contours indicate that the concentration of frozen carbon monoxide increases towards the center of the “bull’s eye.” These data were acquired by the spacecraft on July 14 and transmitted to Earth on July 16.
14. A glimpse at Pluto's moon, Nix
Pluto's third-largest moon, after Charon and Hydra, Nix emerges from the darkness. Credit: NASA-JHUAPL-SWRI
Four different moons are known to circle around Pluto and Charon, Hydra, Nix, Kerberos and Styx (in order of size). An image of Hydra was revealed on Wednesday, and now Nix has been revealed. This tiny moon is estimated at around 40 km across, and this image is very likely looking down the axis of an elongated moon.
15. Charon closeup reveals craters and a "Mountain in a Moat".
A zoomed in section of Charon's surface, captured by New Horizons 6:30 a.m. EDT on July 14, 2015, reveals striking surface features on this icy moon. Credits: NASA-JHUAPL-SwRI
According to NASA:
The image shows an area approximately 200 miles (300 kilometers) from top to bottom, including few visible craters.
"The most intriguing feature is a large mountain sitting in a moat," said Jeff Moore with NASA’s Ames Research Center, Moffett Field, California, who leads New Horizons’ Geology, Geophysics and Imaging team. "This is a feature that has geologists stunned and stumped."
This image gives a preview of what the surface of this large moon will look like in future close-ups from NASA's New Horizons spacecraft. This image is heavily compressed; sharper versions are anticipated when the full-fidelity data from New Horizons' Long Range Reconnaissance Imager (LORRI) are returned to Earth.
16. Pluto's young, mostly crater-less surface is remarkable.
A zoomed-in view of a location to the south of the "Heart" of Pluto, also released on Wednesday, showing tall mountains, some up to 3,500 metres tall, on the surface of Pluto. Credits: NASA/JHUAPL/SWRI with edits by author
Why is this remarkable?
Pluto and Charon are in the middle of the Kuiper Belt, a band of space around the Sun with an array of icy/rocky objects floating around, similar to the asteroid belt between Mars and Jupiter. That alone should mean there's enough "stuff" floating around that will periodically smack into nearly every region of Pluto's surface, but seeing as every other object in the solar system with a static surface is littered with craters, there should be far more seen in these close-up images.
Since it is unlikely that Pluto has simply been lucky enough to avoid impacts, the surface of the dwarf planet must be renewed on a fairly regular basis. This means that Pluto is geologically active. That is, there must be some kind of heating process going on inside it that will cause phenomena like geysers or up-welling of water - something to bring fresh material to the surface of Pluto to fill in craters and erase them from the surface.
This is a mystery that may take some time to resolve.
Also to note in this image, some of the mountains present in this image are up to 3,500 metres tall, or roughly the height of some of the peaks in the Canadian Rockies.
17. Charon reveals a similar youthful appearance
High Resolution image of Pluto's moon Charon, released on Wednesday, rivals the one taken of Pluto the day before. Some of the chasms on the surface are up to 7 to 9 kilometres deep. Credits: NASA/JHUAPL/SWRI
Just as on Pluto, Charon also shows some cratering, but not as much as was thought - revealing that it, too, appears to be geologically active.
What's the big deal here?
Other geologically-active icy bodies in our solar system - such as Europa and Enceladus - are in orbit of massive gas giant planets. Enceladus' orbit around around Saturn, for example, is not a perfect circle. The elliptical path it traces around the planet takes it farther away at some points and closer in at others, and this means that the moon experiences different gravitational pull from the planet at different points in its orbit. This causes the moon to "flex," which causes frictional heating inside the moon, quite probably supporting a warm ocean of liquid salt water underneath its icy crust, but also causing plumes of water vapour to shoot out above the surface. Some of this water vapour goes into producing Saturn's E ring, but parts of it also rain back down on the moon, covering the surface with fresh ice and snow, which renews the surface terrain.
If this is what's happening with Pluto and Charon, the question becomes: without a gas giant to cause tidal forces inside the pair, what would be the source of the geological activity?
In addition, this image reveals extensive canyons and chasms, some of which reach to depths of 7 to 9 kilometres below the surface - or up to 5 times the depth of the Grand Canyon here on Earth!
18. The features on Pluto now have unofficial names straight out of our darkest nightmares
In an effort to distinguish one "dark spot" from another, names like Balrog and Cthulhu showed up as identifiers in one of the latest images of Pluto's surface.
Courtesy: Mika McKinnon and Emily Lakdawalla, Image Credit: Björn Jónsson/NASA-JHUAPL-SWRI
The list so far, drawn from names suggested by the public months ago on OurPluto.org), includes:
- Balrog: a creature of shadow and dark fire from Tolkien's world of Middle Earth, Gandalf the Grey faced down this "flame of Udûn" at Moria's Bridge of Khazad-dûm
- Cthulhu: one of the Great Old Ones described by H.P. Lovecraft, this elder god slumbers at the bottom of the ocean, waiting for the time when it will awake and destroy the world
- Hun-Came and Vucub-Came: "One-Death" and "Seven-Death," respectively, these Mayan death gods ruled over the Mayan underworld, Xibalba, and were defeated by the mythical Hero Twins.
- Krun: "The Mountain-of-Flesh," Overlord of the Underworld in the Mandaean faith. The Mandaeans are the last surviving Gnostic group from late antiquity
- Meng-p’o: from Chinese mythology, this Buddhist goddess gives the Bittersweet Broth of Oblivion to souls preparing for reincarnation, so they will forget their previous life
- Ala: Earth and Underworld goddess of the Igbo people in southeastern Nigeria
A similar naming convention has popped up for Charon, with the moon's dark polar region earning the nickname "Mordor" from the mission team.
What's with all the "dark" names? Pluto was named in 1934, based on the suggestion of an 11-year-old Oxford girl named Venetia Burney, after the Roman god of the Underworld. The trend continued with the discovery of Charon, since although the name was apparently chosen by astronomer James Christy (who discovered Charon in 1978) to honour his wife, Charlene, it coincided with the name of the mythical Greek figure that would ferry souls across the River Styx into Hades. Since then, everything associated with Pluto has taken on the name of mythical figures of death, destruction or darkness.
I did a quick mapping of the #Charon Mordor region imaged by @NewHorizons2015 @NASANewHorizons pic.twitter.com/swNQ1bKkGl
— Dr. Bruce Betts (@RandomSpaceFact) July 15, 2015
19. Pluto's terrain is coated in a layer of frozen methane and nitrogen.
This colourful image shows patterns of infrared light absorption by methane on Pluto's surface - ranging from no absorption (green) to medium-strong absorption (blue) to the strongest absorption (red). Credits: NASA/JHUAPL/SWRI
According to NASA:
The latest spectra from New Horizons Ralph instrument reveal an abundance of methane ice, but with striking differences from place to place across the frozen surface of Pluto.
"We just learned that in the north polar cap, methane ice is diluted in a thick, transparent slab of nitrogen ice resulting in strong absorption of infrared light," said New Horizons co-investigator Will Grundy, Lowell Observatory, Flagstaff, Arizona. In one of the visually dark equatorial patches, the methane ice has shallower infrared absorptions indicative of a very different texture. "The spectrum appears as if the ice is less diluted in nitrogen,” Grundy speculated “or that it has a different texture in that area."
20. Pluto's moon, Hydra, is smaller and brighter than we thought
This pixelated bright object is Hydra, the outermost of Pluto's five moons, taken during the flyby on Tuesday, July 14. Credits: NASA/JHUAPL/SWRI
Discovered in 2005, Hydra was categorized as Pluto's second-largest moon, at an estimated 58 kms wide (just slightly larger than 56 km-wide Nyx), however this new image that arrived on Earth on Wednesday may bump it down in the rankings. Based on this view from New Horizons, the very first direct image taken of the tiny moon, the new estimate puts it at 43 km by 33 km, possibly making Nyx the second largest. New data and images returned of Nyx (due sometime soon), may revise its size estimate as well, so the jury's still out on this one.
It's clear now that Hydra is so bright because its surface is largely composed of water ice, and this is just the lowest resolution look at the moon, at the moment. Future downloads from the spacecraft will reveal it in even more striking detail.
21. The New Horizons team is incredibly excited about these findings
NASA held a press briefing at 3 p.m. ET on Wednesday, July 15, to discuss the above findings. Watch below to get a deeper sense of what these discoveries mean, and to share in the excitement the team is experiencing in the aftermath of this incredible mission.
22. Pluto maintains its place as King of the Kuiper Belt
Based on data collected by New Horizons, Pluto and Charon's sizes have been locked down - Pluto at 2370 km (slightly larger than thought) and Charon at 1208 km.
Highest resolution images of Pluto and Charon so far, noting their confirmed diameters. Credit: NASA-JHUAPL-SWRI, with edits by author.
With this confirmation, Pluto retains its seat as the largest object in the Kuiper belt, beating out fellow dwarf planet Eris by at least 32 kilometres.
This doesn't change Pluto's status from dwarf planet to planet, though. Not only does Pluto sometimes count the ice giant Neptune as being in "its neighborhood," even if you were to count Pluto and Charon as a binary planet, adding their masses together for consideration, they are still outweighed by the massive chunks of ice floating around in this portion of the solar system.
23. False-colour images reveal the varied terrain on these distant worlds:
False-colour composite images of Pluto and Charon, taken on July 13 and enhanced to show off differences in terrain and features on the surface. Credit: NASA/JHUAPL/SwRI
By combining three different filter images from New Horizons' Ralph instrument, the science team was able to produce these images of Pluto and Charon.
According to NASA:
The new color images reveal that the “heart” of Pluto actually consists of two remarkably different-colored regions. In the false-color image, the heart consists of a western lobe shaped like an ice cream cone that appears peach color in this image. A mottled area on the right (east) side looks bluish. A mid-latitude band appears in shades ranging from pale blue through red. Even within the northern polar cap, in the upper part of the image, various shades of yellow-orange indicate subtle compositional differences.
The surface of Charon is viewed using the same exaggerated color. The red on the dark northern polar cap of Charon is attributed to hydrocarbon and other molecules, a class of chemical compounds called tholins. The mottled colors at lower latitudes point to the diversity of terrains on Charon.
Tholins are important because they have been found elsewhere in the solar system, such as on Earth in its primordial past, and more recently on Saturn's moon, Titan. These molecules, which are formed when ultraviolet light from the Sun interacts with compounds like methane, can form an effective barrier against UV light, similar to how ozone does this here on Earth. While not having anything directly to do with biological life, their presence could protect biological life - were it to develop there - from exposure to deadly solar radiation.
Also, due to the way Pluto's thin, tenuous atmosphere interacts with the solar wind, ionized nitrogen is blown out in a plume towards the dark side of the planet. Since Charon orbits directly through a portion of this plume, it very likely picks up some of these ions, which would be deposited on its surface.
24. Geological features identified on the surfaces of Pluto and Charon
Credit: NASA/JHUAPL/SwRI
Credit: NASA/JHUAPL/SwRI
25. Pre-encounter images better and better with each day
New Horizons' closest pre-encounter view of Pluto, taken from 766,000 km away on July 13 - the closest image we will see of the dwarf planet until Wednesday. Credits: NASA-JHUAPL-SWRI
July 12, 2015 views of Charon and Pluto, with colour data added from New Horizons' Ralph instrument.
Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Black and white LORRI images from July 13, 2015.
Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Images from New Horizons' LORRI instrument, showing how the surface details have revealed themselves over the past 3 months. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
RELATED: Check out the latest briefings and commentary on these findings from the New Horizons team!
Watch Amy Shira Teitel, from the New Horizons team, in the video series Pluto in a Minute:
Sources: NASA | JHU APL | OurPluto.org | Wikipedia | DeliriumsRealm | GodChecker.com
