ALMA Captures Never-Before-Seen Details of Protoplanetary Disk

ALMA’s best image of a protoplanetary disk to date. This picture of the nearby young star TW Hydrae reveals the classic rings and gaps that signify planets are in formation in this system. Credit: S. Andrews (Harvard-Smithsonian CfA); B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)
ALMA’s best image of a protoplanetary disc to date. This picture of the nearby young star TW Hydrae reveals the classic rings and gaps that signify planets are in formation in this system.
ALMA’s best image of a protoplanetary disk to date. This picture of the nearby young star TW Hydrae reveals the classic rings and gaps that signify planets are in formation in this system. Credit: S. Andrews (Harvard-Smithsonian CfA); B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)

TW Hydrae is a special star. Located 175 light years from Earth in the constellation Hydra the Water Snake, it sits at the center of a dense disk of gas and dust that astronomers think resembles our solar system when it was just 10 million years old. The disk is incredibly clear in images made using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, which employs 66 radio telescopes sensitive to light just beyond that of infrared.  Spread across more than 9 miles (15 kilometers), the ALMA array acts as a gigantic single telescope that can make images 10 times sharper than even the Hubble Space Telescope.

This photo of the ALMA antennas on the Chajnantor Plateau in Chile, more than 16,000 feet (5000 meters) above sea level, was taken a few days before the start of ALMA Early Science and shows only one cluster of the 66 dishes. ALMA views the sky in "submillimeter" light, a slice of the spectrum invisible to the human eye that lies between infrared and radio waves. Credit: ALMA (ESO/NAOJ/NRAO)/W. Garnier (ALMA)
This photo of the ALMA antennas on the Chajnantor Plateau in Chile, more than 16,000 feet (5000 meters) above sea level, was taken a few days before the start of ALMA Early Science and shows only one cluster of the 66 dishes. ALMA views the sky in submillimeter light, a slice of the spectrum invisible to the human eye that lies between infrared and radio waves. Credit: ALMA (ESO/NAOJ/NRAO)/W. Garnier (ALMA)

Astronomers everywhere point their telescopes at TW Hydrae because it’s the closest infant star in the sky. With an age of between 5 and 10 million years, it’s not even running on hydrogen fusion yet, the process by which stars convert hydrogen into helium to produce energy. TW Hydrae shines from the energy released as it contracts through gravity. Fusion and official stardom won’t begin until it’s dense enough and hot enough for fusion to fire up in its belly.

ALMA image of the planet-forming disk around the young, sun-like star TW Hydrae. The inset image (upper right) zooms in on the gap nearest to the star, which is at the same distance as the Earth is from the sun, and may show an infant version of our home planet emerging from the dust and gas. The additional concentric light and dark features represent other planet-forming regions farther out in the disk. Credit: S. Andrews (Harvard-Smithsonian CfA), ALMA (ESO/NAOJ/NRAO)
ALMA image of the planet-forming disk around the young, sun-like star TW Hydrae. The inset image (upper right) zooms in on the gap nearest to the star, which is at the same distance as the Earth is from the sun, and may show an infant version of our home planet emerging from the dust and gas. The additional concentric light and dark features represent other planet-forming regions farther out in the disk. Credit: S. Andrews (Harvard-Smithsonian CfA), ALMA (ESO/NAOJ/NRAO)

We see most protoplanetary disks at various angles, but TW’s has a face-on orientation as seen from Earth, giving astronomers a rare, undistorted view of the complete disk around the star. The new images show amazing detail, revealing a series of concentric bright rings of dust separated by dark gaps. There’s even indications that a planet with an Earth-like orbit has begun clearing an orbit.

“Previous studies with optical and radio telescopes confirm that TW Hydrae hosts a prominent disk with features that strongly suggest planets are beginning to coalesce,” said Sean Andrews with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, USA and lead author on a paper published today in the Astrophysical Journal Letters.

Blurry as it is, the detail here is staggering. It shows a gap about 93 million miles from the central starsuggesting that a planet with a similar orbit to Earth is forming there. Credit: S. Andrews (Harvard-Smithsonian CfA); B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)
The model (at left) of a protoplanetary disk shows a newly forming star at the center of a saucer-shaped dust cloud. At right, a close up of TW Hydrae taken by ALMA shows a gap about 93 million miles from the central star, suggesting that a planet with a similar orbit to Earth is forming there. Credit: (Left: L. Calcada). Right: S. Andrews (Harvard-Smithsonian CfA); B. Saxton (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO)

Pronounced gaps that show up in the photos above are located at 1.9 and 3.7 billion miles (3-6 billion kilometers) from the central star, similar to the average distances from the sun to Uranus and Pluto in the solar system. They too are likely to be the results of particles that came together to form planets, which then swept their orbits clear of dust and gas to sculpt the remaining material into well-defined bands. ALMA picks up the faint emission of submillimeter light emitted by dust grains in the disk, revealing details as small as 93 million miles (150 million kilometers) or the distance of Earth from the sun

This image compares the size of the solar system with HL Tauri and its surrounding protoplanetary disc. Although the star is much smaller than the Sun, the disc around HL Tauri stretches out to almost three times as far from the star as Neptune is from the Sun. Credit:ALMA (ESO/NAOJ/NRAO)
This image compares the size of the solar system with HL Tauri and its surrounding protoplanetary disc. Although the star is much smaller than the Sun, the disc around HL Tauri stretches out to almost three times as far from the star as Neptune is from the Sun. Credit:ALMA (ESO/NAOJ/NRAO)

“This is the highest spatial resolution image ever of a protoplanetary disk from ALMA, and that won’t be easily beaten in the future!” said Andrews.

Earlier ALMA observations of another system, HL Tauri, show that even younger protoplanetary disks — a mere 1 million years old — look remarkably similar.  By studying the older TW Hydrae disk, astronomers hope to better understand the evolution of our own planet and the prospects for similar systems throughout the Milky Way.

Jupiter Just Got Nailed By Something

Austrian amateur astronomer Gerrit Kernbauer recorded these brief flash of light at Jupiter's limb on March 17, 2016. It was confirmed by another amateur video observation made by John McKeon of Ireland. Credit: Gerrit Kernbauer
Austrian amateur astronomer Gerrit Kernbauer recorded these brief flash of light at Jupiter's limb on March 17, 2016. It was confirmed by another amateur video observation made by John McKeon of Ireland. Credit: Gerrit Kernbauer
Austrian amateur astronomer Gerrit Kernbauer recorded these brief flash of light at Jupiter’s limb on March 17, 2016. It was confirmed by another amateur video observation made by John McKeon of Ireland. Credit: Gerrit Kernbauer

Jupiter may be the biggest planet, but it sure seems to get picked on. On March 17, amateur astronomer Gerrit Kernbauer of Mödling, Austria, a small town just south of Vienna, was filming Jupiter through his 7.8-inch (200mm) telescope. 10 days later he returned to process the videos and discovered a bright flash of light at Jupiter’s limb.


Possible asteroid or comet impact on Jupiter on March 17

“I was observing and filming Jupiter with my Skywatcher Newton 200 telescope, writes Kernbauer. “The seeing was not the best, so I hesitated to process the videos. Nevertheless, 10 days later I looked through the videos and I found this strange light spot that appeared for less than one second on the edge of the planetary disc. Thinking back to Shoemaker-Levy 9, my only explanation for this is an asteroid or comet that enters Jupiter’s high atmosphere and burned up/explode very fast.”

Comet Shoemaker-Levy 9 broke up into many fragments (upper left photo) which later slammed into Jupiter's southern hemisphere one after another to create a string of dark blotches in July 1994. Credit: NASA/ESA
Comet Shoemaker-Levy 9 broke up into many fragments (upper left photo) which later slammed into Jupiter’s southern hemisphere one after another to create a string of dark blotches in July 1994. Credit: NASA/ESA

The flash certainly looks genuine, plus we know this has happened at Jupiter before. Kernbauer mentions the first-ever confirmed reported comet impact that occurred in July 1994. Comet Shoemaker-Levy 9, shattered to pieces from strong tidal forces when it passed extremely close to the planet in 1992, returned two years later to collide with Jupiter — one fragment at a time.  21 separate fragments pelted the planet, leaving big, dark blotches in the cloud tops easily seen in small telescopes at the time.


Video of possible Jupiter impact flash by John McKeon on March 17, 2016

Not long after Kernbauer got the word out, a second video came to light taken by John McKeon from near Dublin, Ireland using his 11-inch (28 cm) telescope. And get this. Both videos were taken in the same time frame, making it likely they captured a genuine impact.

With the advent of cheap video cameras, amateurs have kept a close eye on the planet, hoping to catch sight of more impacts. Two factors make Jupiter a great place to look for asteroid / comet collisions. First, the planet’s strong gravitational influence is able to draw in more comets and asteroids than smaller planets. Second, its powerful gravity causes small objects to accelerate faster, increasing their impact energy.

According to Bad Astronomy blogger Phil Plait: “On average (and ignoring orbital velocity), an object will hit Jupiter with roughly five times the velocity it hits Earth, so the impact energy is 25 times as high.” Simply put, it doesn’t take something very big to create a big, bright bang when it slams into Jove’s atmosphere.

It wasn’t long before the next whacking. 15 years to be exact.

This impact spot, discovered in 2009 by Anthony Wesley, was also visible in amateur telescopes. Credit: NASA, ESA, and H. Hammel (Space Science Institute, Boulder, Colo.), and the Jupiter Impact Team
This impact spot, discovered in 2009 by Anthony Wesley, was also visible in amateur telescopes. Credit: NASA, ESA, and H. Hammel (Space Science Institute, Boulder, Colo.), and the Jupiter Impact Team

On July 19, 2009, Australian amateur Anthony Wesley was the first to record a brand new dark scar near Jupiter’s south pole using a low-light video camera on his telescope. Although no one saw or filmed the impact itself, there was no question that the brand new spot was evidence of the aftermath: NASA’s Infrared Telescope Facility at Mauna Kea picked up a bright spot at the location in infrared light.


Jupiter impact event recorded by Christopher Go on June 3, 2010

Once we started looking closely, the impacts kept coming. Wesley hit a second home run on June 3, 2010 with video of an impact flash, later confirmed on a second video made by Christopher Go. This was quickly followed by another flash filmed by Japanese amateur astronomer Masayuki Tachikawa on August 20, 2010.


Jupiter impact flash on August 20, 2010 by Masayuki Tachikawa

Prior to this month’s event, amateur Dan Petersen visually observed a impact flash lasting 1-2 seconds in his 12-inch (30.5 cm) scope on September 10, 2012, which was also confirmed on webcam by George Hall.

Keep ’em comin’!

See Historic Comet BA14 Up Close In These New Radar Images

These radar images of comet P/2016 BA14 were taken on March 23, 2016, by scientists using an antenna of NASA's Deep Space Network at Goldstone, California. At the time, the comet was about 2.2 million miles (3.5 million kilometers) from Earth. Credit: NASA/JPL-Caltech/GSSR
These radar images of comet P/2016 BA14 were taken on March 23, 2016, by scientists using an antenna of NASA's Deep Space Network at Goldstone, California. At the time, the comet was about 2.2 million miles (3.5 million kilometers) from Earth. Credit: NASA/JPL-Caltech/GSSR
These radar images of comet P/2016 BA14 were taken on March 23, 2016, by scientists using an antenna of NASA’s Deep Space Network at Goldstone, California. At the time, the comet was about 2.2 million miles (3.5 million kilometers) from Earth. Credit: NASA/JPL-Caltech/GSSR

On March 22, Comet P/2016 BA14 (Pan-STARRS) flew just 2.2 million miles (3.5 million kilometers) from Earth, making it the third closest comet ever recorded. The last time a comet appeared on our doorstep was in 1770, when Lexell’s Comet breezed by at about half that distance. Through a telescope, comet BA14 looked (and still looks) like a faint star, though time exposures reveal a short, weak tail. With an excellent map and large amateur telescope you might still find it making a bead across the Big Dipper and constellation Bootes tonight through the weekend.


Flyby Comet Imaged by Radar

While normal telescopes show few details, NASA’s Goldstone Solar System Radar in California’s Mojave Desert pinged P/2016 BA14 with radar over three nights during closest approach and created a series of crisp, detailed images from the returning echoes. They show a bigger comet than expected — about 3,000 feet (one kilometer) across —  and resolve features as small as 26 feet (8 meters) across.

“The radar images show that the comet has an irregular shape: looks like a brick on one side and a pear on the other,” said Shantanu Naidu, a researcher at NASA’s Jet Propulsion Laboratory. “We can see quite a few signatures related to topographic features such as large flat regions, small concavities and ridges on the surface of the nucleus.”

I honestly thought we’d see a more irregular shape assuming that astronomers were correct in thinking that BA14 broke off from its parent 252P/LINEAR though it’s possible it happened so long ago that the “damage” has been repaired by vaporizing ice softening its contours.

Comets are as dark as charcoal but appear light only because the sun illuminates them against the blackness of outer space. I shone a flashlight on a charcoal briquette (left) to simulate comet lighting. The same charcoal when viewed in normal light appears black. Credit: Bob King
Comets are as dark as charcoal but appear light only because the sun illuminates them against the blackness of outer space. I shone a flashlight on a charcoal briquette (left) to simulate comet lighting. The same charcoal when viewed in normal light appears black. Credit: Bob King

Radar also shows that the comet is rotating on its axis once every 35 to 40 hours. While radar eyes focused on BA14, Vishnu Reddy, of the Planetary Science Institute, Tucson, Arizona, used the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii to examine the comet in infrared light. He discovered its dark surface reflects less than 3% of the sunlight that falls on it. The infrared data is expected to yield clues of the comet’s composition as well.

Illustration of Comet 67P/C-G brought down to Earth in the city of Los Angeles, Calif. Compare to the same image (below) as viewed in space. Credit: ESA and anosmicovni
Illustration of Comet 67P/Churyumov-Gerasimenko brought down to Earth in the city of Los Angeles, Calif. Not only can we appreciate its size but also its truly dark surface.  Credit: ESA and anosmicovni

Comets are exceptionally dark objects often compared to the appearance of a fresh asphalt road or parking lot. They appear bright in photos because seen against the blackness of space, they’re still reflective enough to stand out. Comet 67P/Churyumov-Gerasimenko, still the apple of the orbiter Rosetta’s eye, is similarly dark, reflecting about 4% of sunlight.

What makes comets so dark even though they composed primarily of ice? Astronomers believe a comet grows a dark ‘skin’ both from accumulated dust and irradiation of its pristine ices by cosmic rays. Cosmic rays loosen oxygen atoms from water ice, freeing them to combine with simple carbon molecules present on comets to form larger, more complex and darker compounds resembling tars and crude oil. Dust settles on a comet’s surface after it’s set free from ice that vaporizes in sunlight.

Comet 67P/C-G photographed from a distance of just 7.5 miles (12 kilometers) on March 19, 2016 by Rosetta's Navcam. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0.
What a view! Comet 67P/C-G photographed from a distance of just 7.5 miles (12 kilometers) on March 19, 2016 by Rosetta’s Navcam. The largest boulder to the right is Cheops, which stands about 82 feet (25 meters) high. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

I live in Minnesota, where our annual State Fair features every kind of deep-fried food you can imagine: deep-fried Twinkies, deep-fried fruit, deep-fried bacon and even deep-fried Smores. Just now, I can’t shake the thought that comets are just another deep-fried confection made of pristine, 4.5-billion-year-old ice toasted by eons of sunlight and cosmic bombardment.

ExoMars Mission Narrowly Avoids Exploding Booster

The ExoMars craft releases the Schiaparelli lander in October in this artist's view. Credit: ESA
At least nine moving objects, all thought to be related to a possible explosion of the Breeze-M upper stage after separation from the ExoMars spacecraft, move across the sky in this animation. ExoMars is further ahead and outside the frame. Credit and copyright: OASI Observatory team; D. Lazzaro, S. Silva / ESA
At least nine moving objects, all thought to be related to a possible explosion of the Breeze-M upper stage after separation from the ExoMars spacecraft, move across the sky in this animation made late on March 14. ExoMars is further ahead and outside the frame. Credit and copyright: OASI Observatory team; D. Lazzaro, S. Silva / ESA

On March 14, the ExoMars mission successfully lifted off on a 7-month journey to the planet Mars but not without a little surprise. The Breeze-M upper booster stage, designed to give the craft its final kick toward Mars, exploded shortly after parting from the probe. Thankfully, it wasn’t close enough to damage the spacecraft.

Michel Denis, ExoMars flight director at the European Space Operations, Center in Darmstadt, Germany, said that the two craft were many kilometers apart at the time of the breakup, so the explosion wouldn’t have posed a risk. Still, the mission team won’t be 100% certain until all the science instruments are completely checked over in the coming weeks.

All went well during the takeoff and final separation of the probe, but then something odd happened. Breeze-M was supposed to separate cleanly into two pieces — the main body and a detachable fuel tank — and maneuver itself to a graveyard or “junk” orbit, where rockets and spacecraft are placed at the end of their useful lives, so they don’t cause trouble with operational satellites.

But instead of two pieces, tracking photos taken at the OASI Observatory in Brazil not long after the stage and probe separated show  a cloud of debris, suggesting an explosion occurred that shattered the booster to pieces. There’s more to consider. Space probes intended to either land or be crashed into planets have to pass through strict sterilization procedures that rocket boosters aren’t subject to. Assuming the Breeze-M shrapnel didn’t make it to its graveyard orbit, there exists the possibility some of it might be heading for Mars. If any earthly bugs inhabit the remains, it could potentially lead to unwanted consequences on Mars.

And this isn’t the first time a Russian Breeze-M has blown up.

According to Russian space observer Anatoly Zak in a recent article in Popular Mechanics, a Breeze-M that delivered a Russian spy satellite into orbit last December exploded on January 16. Propellant in one of its fuel tanks may not have been properly vented into space; heated by the sun, the tank’s contents likely combusted and ripped the stage apart. A similar incident occurred in October 2012.

The ExoMars craft releases the Schiaparelli lander in October in this artist's view. Credit: ESA
Artist view of the ExoMars craft releasing the Schiaparelli lander in October. Credit: ESA

For now, we’ll embrace the good news that the spacecraft, which houses the Trace Gas Orbiter (TGO) and the Schiaparelli lander, are underway to Mars and in good health.

ExoMars is a joint venture between the European Space Agency (ESA) and the Russian Federal Space Agency (Roscosmos). One of the mission’s key goals is to follow up on the methane detection made by ESA’s Mars Express probe in 2004 to understand where the gas comes from. Mars’ atmosphere is 95% carbon dioxide with the remaining 5% divided among nitrogen, argon, oxygen and others including small amounts of methane, a gas that on Earth is produced largely by living creatures.

NASA researchers using telescopes right here on Earth also detected multiple methane plumes coming from the surface on Mars in 2003. Credit: Trent Schindler/NASA
NASA researchers using telescopes right here on Earth also detected multiple methane plumes coming from the surface on Mars in 2003. Credit: Trent Schindler/NASA

Scientists want to know how martian methane got into the atmosphere. Was it produced by biology or geology? Methane, unless it is continuously produced by a source, only survives in the Martian atmosphere for a few hundreds of years because it quickly breaks down to form water and carbon dioxide. Something is refilling the atmosphere with methane but what?

TGO will also look at potential sources of other trace gases such as volcanoes and map the planet’s surface. It can also detect buried water-ice deposits, which, along with locations identified as sources of the trace gases, could influence the choice of landing sites of future missions.

The orbiter will also act as a data relay for the second ExoMars mission — a rover and stationary surface science platform scheduled for launch in May 2018 and arriving in early 2019.

Schiaparelli will demonstrate the capability of ESA and European industry to perform a controlled landing on the surface of Mars. Credit: ESA
Schiaparelli will demonstrate the capability of ESA and European industry to perform a controlled landing on the surface of Mars. It will also gather data on Mars’ atmosphere. Credit: ESA

On October 16, when the spacecraft is still 559,000 miles (900,000 kilometers) from the Red Planet, the Schiaparelli lander will separate from the orbiter and three days later parachute down to the Martian surface. The orbiter will take measurements of the planet’s atmosphere (including methane) as well as any atmospheric electrical fields.

Clouds gather over Mars' Hellas Basin in this photo taken March 23. The Red Planet has intrigued humankind for centuries. Credit: Anthony Wesley
Clouds gather over Mars’ Hellas Basin in this photo taken March 23. The Red Planet has intrigued humankind for centuries. Credit: Anthony Wesley

Mars is a popular place. There are currently five active orbiters there: two European (Mars Express and Mars Odyssey), two American (Mars Reconnaissance Orbiter and MAVEN), one Indian (Mars Orbiter Mission) and two rovers (Opportunity and Curiosity) with another lander and orbiter en route!

Best NASA Images Yet Of Ceres’ Brightest Spot

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The bright central spots near the center of Occator Crater are shown in enhanced color in this view from NASA’s Dawn spacecraft. The view was produced by combining the highest resolution images taken in February 2016 at an image scale of 115 feet (35 meters) per pixel with color images obtained in September 2015 at a lower resolution added. Click for a highest-res view. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

Ah, dome sweet dome. Scientists from NASA’s Dawn mission unveiled new images from the spacecraft’s lowest orbit at Ceres, including highly anticipated views of Occator Crater, at the 47th annual Lunar and Planetary Science Conference in The Woodlands, Texas, on Tuesday. The new images, taken from Dawn’s low-altitude mapping orbit (LAMO) of 240 miles (385 kilometers) above Ceres, reveal a dome in a smooth-walled pit in the bright center of the crater. Linear fractures crisscross the top and flanks of the dome with still more fractures slicing across the nearby plains.

Occator Crater, measuring 57 miles (92 kilometers) across and 2.5 miles (4 kilometers) deep, contains the brightest area on Ceres. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI
Occator Crater, measuring 57 miles (92 kilometers) across and 2.5 miles (4 kilometers) deep, contains the brightest area on Ceres. This photo has been exposed to show detail in the crater and landscape, so the bright spots are overexposed. The closeup photos on the other hand are correctly exposed to show detail in the spots but necessarily underexpose the landscape and make it look very dark. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

“Before Dawn began its intensive observations of Ceres last year, Occator Crater looked to be one large bright area. Now, with the latest close views, we can see complex features that provide new mysteries to investigate,” said Ralf Jaumann, planetary scientist and Dawn co-investigator at the German Aerospace Center (DLR) in Berlin. “The intricate geometry of the crater interior suggests geologic activity in the recent past, but we will need to complete detailed geologic mapping of the crater in order to test hypotheses for its formation.”

The bright central spots near the center of Occator Crater are shown in enhanced color in this view from NASA's Dawn spacecraft. The view was produced by combining the highest resolution images taken in February 2016 (at image scales 115 feet (35 meters) per pixel of 35 meters with color images obtained in September 2015 at a lower resolution. Click for a highest-res view. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI
Black and white view of the bright spots in Occator Crater. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

Like me, you’ve probably been anticipating LAMO for months, when we’d finally get our clearest view of the famous “bright spots”. Spectral observations have shown that the patches are consistent with a magnesium sulfate called hexahydrite that resembles the more familiar Epsom salts here on Earth. Scientists think these salt-rich areas were residue left behind when water-ice sublimated in the past. Impacts from asteroids could have broken into Ceres’ crust and possibly unearthed salt-rich ices. Exposed to the vacuum of space, the ice would have sublimated (vaporized), leaving the salt behind.

This global map shows the surface of Ceres in enhanced color, encompassing infrared wavelengths beyond human visual range. Images taken using infrared (965 nanometers), green (555 nanometers) and blue (438 nanometers) spectral filters were combined to create this view. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI
This global map shows the surface of Ceres in enhanced color, including infrared wavelengths beyond human visual range. Photos were taken using infrared, green and blue filters and combined to create this view. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

The team also released an enhanced color map of the surface of Ceres that reveals a diversity of surface materials and how they relate to Ceres’ landforms. The dwarf planet doesn’t have as many large impact basins as scientists expected, but the number of smaller craters generally matches their predictions. The blue material highlighted in the color map is related to flows, smooth plains and mountains, which appear to be very young surface features.

“Although impact processes dominate the surface geology on Ceres, we have identified specific color variations on the surface indicating material alterations that are due to a complex interaction of the impact process and the subsurface composition,” Jaumann said. “Additionally, this gives evidence for a subsurface layer enriched in ice and volatiles.”

 This map shows a portion of the northern hemisphere of Ceres with neutron counting data acquired by the gamma ray and neutron detector (GRaND) instrument aboard NASA's Dawn spacecraft. These data reflect the concentration of hydrogen in the upper yard (or meter) of regolith, the loose surface material on Ceres. The color information is based on the number of neutrons detected per second by GRaND. Counts decrease with increasing hydrogen concentration. The color scale of the map is from blue (lowest neutron count) to red (highest neutron count). Lower neutron counts near the pole suggest the presence of water ice within about a yard (meter) of the surface at high latitudes.

This map shows part of Ceres’ northern hemisphere with neutron counting data from Dawn’s gamma ray and neutron detector (GRaND) instrument and reflect the concentration of hydrogen in the upper yard (or meter) of regolith, the loose surface material on Ceres. Colors are based on the number of neutrons detected per second by GRaND. Counts decrease with increasing hydrogen concentration. The color scale of the map is from blue (lowest neutron count) to red (highest neutron count). Lower neutron counts near the pole suggest the presence of water ice within about a yard (meter) of the surface at high latitudes. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

We’re learning more about that subsurface ice thanks to Dawn’s Gamma Ray and Neutron Detector (GRaND). Neutrons and gamma rays produced by cosmic rays interacting with the topmost yard (meter) of the loose rock and dust called regolith provide a fingerprint of Ceres’ chemical makeup. Lower counts indicate the presence of hydrogen, and since water’s rich in hydrogen (H2o), the results from GRanD suggest concentrations of water ice in the near-surface at high latitudes.

“Our analyses will test a longstanding prediction that water ice can survive just beneath Ceres’ cold, high-latitude surface for billions of years,” said Tom Prettyman, the lead for GRaND and Dawn co-investigator at the Planetary Science Institute, Tucson, Arizona.

Ceres’ Oxo Crater (right) is the only place on the dwarf planet where water has been detected on the surface so far. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI
Ceres’ Oxo Crater (right) is the only place on the dwarf planet where water has been detected on the surface so far. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

Dawn scientists also reported that the Visual and Infrared Mapping Spectrometer (VIR) has detected water at Oxo Crater, a young, 6-mile-wide (9-kilometer-wide) feature in Ceres’ northern hemisphere. This water could either be bound up in minerals or exist as ice and may have been exposed during a landslide or impact or a combination of the two events.  Oxo is the only place on Ceres where water has been detected at the surface so far.

Ceres' Haulani Crater (21 miles, 34 kilometers wide) is shown in these views from the visible and infrared mapping spectrometer (VIR) aboard NASA's Dawn spacecraft. These views reveal variations in the region's brightness, mineralogy and temperature at infrared wavelengths. The image at far left shows brightness variations in Haulani. Light with a wavelength of 1200 nanometers is shown in blue, 1900 nanometers in green and 2300 nanometers in red. The view at center is a false color image, highlighting differences in the types of rock and ejected material around the crater. Scientists see this as evidence that the material in this area is not uniform, and that the crater's interior has a different composition than its surroundings.
Ceres’ Haulani Crater (21 miles, 34 kilometers wide) is shown in these views made with VIR. They reveal variations in the region’s brightness, mineralogy and temperature at infrared wavelengths in the types of rock and ejected material around the crater. Scientists see this as evidence that the material in this area is not uniform, and that the crater’s interior has a different composition than its surroundings. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

Not only have scientists found evidence of possible extensive subsurface ice, but the composition of the surface is variable. Using VIR, which measures mineral composition by how those minerals reflect sunlight, they found that Haulani Crater shows a different proportion of surface materials than its surroundings. While the surface of Ceres is mostly made of a mixture of materials containing carbonates and phyllosilicates (clays), their relative proportion varies across the surface.

“False-color images of Haulani show that material excavated by an impact is different than the general surface composition of Ceres. The diversity of materials implies either that there is a mixed layer underneath, or that the impact itself changed the properties of the materials,” said Maria Cristina de Sanctis, the VIR instrument lead scientist.

All these cool stuff we’re finding out about this small body makes it nearly as exciting as Pluto. Taking a closer look is the best form of education.

Stunning Conjunction of Mars and Beta Scorpii This Week

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Face south tomorrow morning at the start of dawn and you might have to look twice for Beta Scorpii. Bright Mars stands right next to the star and will pass very close to the star on Wednesday morning, March 16. Diagram: Bob King, source: Stellarium

Planets can sneak up on you. Especially the ones that don’t rise till you’re in bed. Take Mars for instance. It’s been ambling east along the morning zodiac all winter long; today it enters Scorpius, rising around 1:30 a.m. Not two days later, the planet will have a spectacularly close conjunction with Beta Scorpii, the topmost star in the scorpion’s head.

This close up of the head of Scorpius shows Mars' progress over the next three mornings. Positions are shown for 5:30 a.m. CDT. Diagram: Bob King, source: Stellarium
This close up of the head of Scorpius shows Mars’ progress over the next three mornings. Positions are shown for 5:30 a.m. CDT. Diagram: Bob King, source: Stellarium

Also known as Graffias, Beta shines at magnitude +2.6  next to the fiery, zero-magnitude Mars. With their striking color contrast, the two would make a superb ring setting: a tiny diamond nestled next to a plump garnet. They’ll be together for several mornings, their separation changing each day: 15 arc minutes on Tuesday (1/2 the diameter of the Full Moon); 9 arc minutes when closest on Wednesday and back out to 23 minutes on Thursday.

In a telescope, diminutive Mars pairs up with gorgeous Graffias. Diagram: Bob King , source: Stellarium
In a telescope, diminutive Mars pairs up with gorgeous Graffias. North is up and left. Beta-1, the brighter of the two, has an additional 1oth magnitude companion half an arc-second away, while Beta-2 is also double with a faint companion 1/10th of arc second distant. That’s not all. Beta-1 is an exceedingly close binary — making Graffias at least a five-star system!  Diagram: Bob King , source: Stellarium

It’s a gas to see two celestial objects approach so closely, but this conjunction offers a rare treat. Did you know that Beta is one of the finest double stars in the sky? It has a fifth magnitude companion 14 arc seconds northeast of the primary. Any telescope will split this jewel and show Mars in the same field of view at both high and low magnifications. That’s just so cool — I sure hope you’ll get to see them.

Mars, in gibbous phase, is still small but starting to show its larger surface features in modest-sized telescopes. This photo, taken on March 13th, shows the  prominent Mare  Acidalium in the planet's northern hemisphere (top) and a hint of the north polar cap. Sinus Aurorae and Mare Erythraeum dominate the south. Credit: Anthony Wesley
Mars, in gibbous phase, is still small but its larger surface features are now visible in modest-sized telescopes. This photo, taken on March 13th, shows Mare Acidalium in the planet’s northern hemisphere (top) and a hint of the north polar cap. Sinus Aurorae and Mare Erythraeum dominate the south. Click for a Mars map. Credit: Anthony Wesley

Mars now measures 10 arc seconds in diameter, small for sure, but big enough to see the larger dark markings and a hint of the north polar cap. The planet is heading for opposition on May 22nd, when it will shine at magnitude -2.0 (brighter than Sirius) with a disk 18.4 arc seconds across, its biggest and closest since 2005.

Let this week’s lovely conjunction serve as a warm-up to the forthcoming season of Mars.

 

18 Billion Solar Mass Black Hole Rotates At 1/3 Speed Of Light

Black-hole-powered galaxies called blazars are the most common sources detected by NASA's Fermi Gamma-ray Space Telescope. They are sources of neutrinos and cosmic rays. Credits: M. Weiss/CfA
Black-hole-powered galaxies called blazars are the most common sources detected by NASA's Fermi Gamma-ray Space Telescope. They are sources of neutrinos and cosmic rays. Credits: M. Weiss/CfA

Way up in the constellation Cancer there’s a 14th magnitude speck of light you can claim in a 10-inch or larger telescope. If you saw it, you might sniff at something so insignificant, yet it represents the final farewell of chewed up stars as their remains whirl down the throat of an 18 billion solar mass black hole, one of the most massive known in the universe.

Black-hole-powered galaxies called blazars are the most common sources detected by NASA's Fermi Gamma-ray Space Telescope. As matter falls toward the supermassive black hole at the galaxy's center, some of it is accelerated outward at nearly the speed of light along jets pointed in opposite directions. When one of the jets happens to be aimed in the direction of Earth, as illustrated here, the galaxy appears especially bright and is classified as a blazar. Credits: M. Weiss/CfA
Artist’s view of a black hole-powered blazar (a type of quasar) lighting up the center of a remote galaxy. As matter falls toward the supermassive black hole at the galaxy’s center, some of it is accelerated outward at nearly the speed of light along jets pointed in opposite directions. When one of the jets happens to be aimed in the direction of Earth, as illustrated here, the galaxy appears especially bright and is classified as a blazar.
Credits: M. Weiss/CfA

Astronomers know the object as OJ 287, a quasar that lies 3.5 billion light years from Earth. Quasars or quasi-stellar objects light up the centers of many remote galaxies. If we could pull up for a closer look, we’d see a brilliant, flattened accretion disk composed of heated star-stuff spinning about the central black hole at extreme speeds.

An illustration of the binary black hole system in OJ287. The predictions of the model are verified by observations. Credit: University of Turku
An illustration of the binary black hole system, OJ 287, showing the massive black hole surrounded by an accretion disk. A second, smaller black hole is believed to orbit the larger. When it intersects the larger’s disk coming and going, astronomers see a pair of bright flares. The predictions of the model are verified by observations. Credit: University of Turku

As matter gets sucked down the hole, jets of hot plasma and energetic light shoot out perpendicular to the disk. And if we’re so privileged that one of those jet happens to point directly at us, we call the quasar a “blazar”. Variability of the light streaming from the heart of a blazar is so constant, the object practically flickers.

Long exposures made with the Hubble Space Telescope showing brilliant quasars flaring in the hearts of six distant galaxies. Credit: NASA/ESA
Long exposures made with the Hubble Space Telescope showing brilliant quasars flaring in the hearts of six distant galaxies. Credit: NASA/ESA

A recent observational campaign involving more than two dozen optical telescopes and NASA’s space based SWIFT X-ray telescope allowed a team of astronomers to measure very accurately the rotational rate the black hole powering OJ 287 at one third the maximum spin rate — about 56,000 miles per second (90,000 kps) —  allowed in General Relativity  A careful analysis of these observations show that OJ 287 has produced close-to-periodic optical outbursts at intervals of approximately 12 years dating back to around 1891. A close inspection of newer data sets reveals the presence of double-peaks in these outbursts.

Illustration of a gradually precessing orbit similar to the precessing orbit of the smaller smaller black hole orbiting the larger in OJ 287. Credit: Willow W / Wikipedia
Illustration of a gradually precessing orbit similar to the precessing orbit of the smaller smaller black hole orbiting the larger in OJ 287. Credit: Willow W / Wikipedia

To explain the blazar’s behavior, Prof. Mauri Valtonen of the University of Turku (Finland) and colleagues developed a model that beautifully explains the data if the quasar OJ 287 harbors not one buy two unequal mass black holes — an 18 billion mass one orbited by a smaller black hole.

OJ 287 is visible due to the streaming of matter present in the accretion disk onto the largest black hole. The smaller black hole passes through the larger’s the accretion disk during its orbit, causing the disk material to briefly heat up to very high temperatures. This heated material flows out from both sides of the accretion disk and radiates strongly for weeks, causing the double peak in brightness.

The orbit of the smaller black hole also precesses similar to how Mercury’s orbit precesses. This changes when and where the smaller black hole passes through the accretion disk.  After carefully observing eight outbursts of the black hole, the team was able to determine not only the black holes’ masses but also the precession rate of the orbit. Based on Valtonen’s model, the team predicted a flare in late November 2015, and it happened right on schedule.

OJ 287 has been fluctuating around 13.5-140 magnitude lately. You can spot in a 10-inch or larger scope in Cancer not far from the Beehive Cluster. Click the image for a detailed AAVSO finder chart. Diagram: Bob King, source: Stellarium
OJ 287 has been fluctuating around 13.5-140 magnitude lately. You can spot it in a 10-inch or larger scope in Cancer not far from the Beehive Cluster. Click the image for a detailed AAVSO finder chart. Diagram: Bob King, source: Stellarium

The timing of this bright outburst allowed Valtonen and his co-workers to directly measure the rotation rate of the more massive black hole to be nearly 1/3 the speed of light. I’ve checked around and as far as I can tell, this would make it the fastest spinning object we know of in the universe. Getting dizzy yet?

Russian Crowdfunded Satellite May Soon Become Brightest “Star” in the Sky

Illustration of the “Beacon” inflating from its canister after reaching orbit. The Mayak Project used the Russian version of Kickstarter called Boomstarter to fund the project. Credit: cosmomayak.ru / Mayak Project
Artist’s view of the proposed Mayak (Beacon) satellite fully unfurled and orbiting Earth. Credit: cosmomayak.ru / Mayak Project

We may soon look up and see a satellite brighter than the space station and even Venus gliding across the night sky if a Russian crowdfunding effort succeeds. An enthusiastic team of students from Moscow University of Mechanical Engineering are using Boomstarter, the Russian equivalent of Kickstarter, to raise the money needed to build and launch a pyramid-shaped satellite made of highly reflective material they’re calling Mayak, Russian for “Beacon”.


Young engineers at Moscow University explain the Mayak Project

To date they’ve collected more than $23,000 or 1.7 million rubles. Judging from the video, the team has built the canister that would hold the satellite (folded up inside) and performed a high-altitude test using a balloon. If funding is secured, Beacon is scheduled to launch on a Soyuz-2 rocket from the Baikonur Cosmodrome in the second quarter of this year.

Illustration of the “Beacon” unfurling from its canister when it reaches orbit. The Mayak Project used the Russian version of Kickstarter called Boomstarter to fund the project. Credit: cosmomayak.ru / Mayak Project
Illustration of the “Beacon” inflating from its canister after reaching orbit. The Mayak Project used the Russian version of Kickstarter called Boomstarter to fund the project. Credit: cosmomayak.ru / Mayak Project

Once in orbit, Beacon will inflate into a pyramid with a surface area of 172 square feet (16 square meters). Made of reflective metallized film 20 times thinner than a human hair, the satellite is expected to become the brightest man-made object in orbit ever. That title is currently held by the International Space Station which can shine as brightly as magnitude -3 or about three times fainter than Venus. The brightest satellites, the Iridiums, can flare to magnitude -8 (as bright as the crescent moon) but only for a few seconds before fading back to invisibility. They form a “constellation” of  some 66 satellites that provide data and voice communications.

A student at the Mayak Lab in Moscow describes the container used to hold the reflective "Beacon" satellite. Credit:
A student at the Mayak Lab in Moscow describes the container used to hold the reflective “Beacon” satellite. Credit: cosmomayak.ru / Mayak Project

A concurrently-developed mobile app would allow users to know when Beacon would pass over a particular location. The students hope to achieve more than just track a bright, moving light across the sky. According to their website, the goal of the project is the “popularization of astronautics and space research in Russia, as well as improving the attractiveness of science and technology education among young people.” They want to show that almost anyone can build and send a spacecraft into orbit, not just corporations and governments.

Further, the students hope to test aerodynamic braking in the atmosphere and find out more about the density of air at orbital altitudes. Interested donors can give anywhere from 300 rubles (about $5) up 300,000 ($4,000). The more money, the more access you’ll have to the group and news of the satellite’s progress; the top donor will get invited to watch the launch on-site.

Moscow University students release the satellite on a test run. Credit: cosmomayak.ru / Mayak Project
Liftoff! Moscow University students release the satellite on a test run. Credit: cosmomayak.ru / Mayak Project

Once finished with the Mayak Project, the team wants to built another version that uses that atmosphere for braking its speed and returning it — and future satellites — safely back to Earth without the need for retro-rockets.

I think all these goals are worthy, and I admire the students’ enthusiasm. I only hope that satellite launching doesn’t become so cheap and popular that we end up lighting up the night sky even further. What do you think?

Clouds Seen On Pluto For First Time

Recent images sent by NASA's New Horizons spacecraft show possible clouds floating over the frozen landscape including the streaky patch at right. Credit: NASA/JHUAPL/SwR
Recent images sent by NASA's New Horizons spacecraft show possible clouds floating over the frozen landscape including the streaky patch at right. Credit: NASA/JHUAPL/SwR
Recent images sent by NASA’s New Horizons spacecraft show possible clouds floating over the frozen landscape including the hazy streak right of center. Credit: NASA/JHUAPL/SwRI

I think we were all blown away when the New Horizons spacecraft looked back at Pluto’s dark side and returned the first photos of a surprisingly complex, layered atmosphere. Colorless nitrogen along with a small percentage of methane make up Pluto’s air. Layers of haze are likely created when the two gases react in sunlight to form tiny, soot-like particles called tholins. These can ultimately grow large enough to settle toward the surface and coat and color Pluto’s icy exterior.

Close up of the back side of Pluto taken by New Horizons shows multiple layers of haze in its mostly nitrogen atmosphere. Credit:
Close up of the back side of Pluto taken by New Horizons shows multiple layers of haze in its mostly nitrogen atmosphere. Credit: NASA/JHUAPL/SwRI

Now it seems Pluto’s atmosphere is capable of doing even more — making clouds! In an e-mail exchange with New Scientist, Lowell Observatory astronomer Will Grundy discusses the possibility that streaks and small condensations within the hazes might be individual clouds. Grundy also tracked a feature as it passed over different parts of the Plutonian landscape below, strongly suggesting a cloud.  If confirmed, they’d be the first-ever clouds seen on the dwarf planet, and a sign this small 1,473-mile-wide (2,370 km) orb possesses an even more complex atmosphere than imagined.

Faint arrows along Pluto's limb point to possible clouds in a low altitude haze layer. More distinct possible clouds are arrowed at left. Credit: NASA/JHUAPL/SwR
Faint arrows along Pluto’s limb point to possible clouds in a low altitude haze layer. More distinct possible clouds are arrowed at left. Credit: NASA/JHUAPL/SwRI
The smooth expanse of the informally named Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. The backlighting highlights more than a dozen layers of haze in Pluto's tenuous but distended atmosphere.
15 minutes after its closest approach, New Horizons snapped this image of the smooth expanse of Sputnik Planum (right) flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. The backlighting highlights more than a dozen layers of haze in Pluto’s tenuous but distended atmosphere. Credit: NASA/JHUAPL/SwRI

Given the onion-like layers of haze and potential clouds, perhaps we shouldn’t be surprise that it snows on Pluto. The New Horizons team announced the discovery this week of a chain of exotic snowcapped mountains stretching across the dark expanse of the informally named Cthulhu Regio. Cthulhu, pronounced kuh-THU-lu and named for a character in American horror writer H.P. Lovecraft’s books, stretches nearly halfway around Pluto’s equator, starting from the west of the vast nitrogen ice plain, Sputnik Planum. At 1,850 miles (3,000 km) long and 450 miles (750 km) wide, Cthulhu is a bit larger than the state of Alaska. But ever so much colder!

A section of Cthulhu Regio boasts peaks covered in methane frost or snow.
The upper slopes of Cthulhu’s highest peaks are coated with a bright material that contrasts sharply with the dark red color of the surrounding plains. Scientists think it’s methane ice condensed from Pluto’s atmosphere. The far right panel shows the distribution of methane ice on the surface. Credit: NASA/JHUAPL/SwRI

Cthulhu’s red color probably comes from a covering of dark tholins formed when methane interacts with sunlight. But new close-up images reveal that the region’s highest mountains appear coated with a much brighter material. Scientists think it’s methane, condensed as ice onto the peaks from Pluto’s atmosphere.

“That this material coats only the upper slopes of the peaks suggests methane ice may act like water in Earth’s atmosphere, condensing as frost at high altitude,” said John Stansberry, a New Horizons science team member.

Compositional data from the New Horizon’s Ralph/Multispectral Visible Imaging Camera (MVIC), shown in the right panel in the image above, shows that the location of the bright ice on the mountain peaks correlates almost exactly with the distribution of methane ice, shown in false color as purple.

New Horizons still has plenty of images stored on its hard drive, so we’re likely to see more clouds, frosty peaks and gosh-knows-what-else as the probe speeds ever deeper into space while returning daily postcards from its historic encounter.

Spotlight On Pluto’s Frozen Polar Canyons

This enhanced color view Long canyons run vertically across the polar area—part of the informally named Lowell Regio, named for Percival Lowell, who founded Lowell Observatory and initiated the search that led to Pluto’s discovery. The widest of the canyons is about 45 miles (75 kilometers) wide and runs close to the north pole. Roughly parallel subsidiary canyons to the east and west are approximately 6 miles (10 kilometers) wide.
This enhanced color view Long canyons run vertically across the polar area—part of the informally named Lowell Regio, named for Percival Lowell, who founded Lowell Observatory and initiated the search that led to Pluto’s discovery. The widest of the canyons is about 45 miles (75 kilometers) wide and runs close to the north pole. Roughly parallel subsidiary canyons to the east and west are approximately 6 miles (10 kilometers) wide.
This enhanced color view shows long canyons running vertically across Pluto’s north polar region — part of the informally named Lowell Regio, named for Percival Lowell, who founded Lowell Observatory and initiated the search that led to Pluto’s discovery. The widest of the canyons is about 45 miles (75 km) wide and runs close to the north pole. Roughly parallel secondary canyons to the east and west are approximately 6 miles (10 km) wide. Click for a hi-res view. Credit: NASA/JHUAPL/SRI

Pluto’s frozen nitrogen custard “heart” has certainly received its share of attention. Dozens of wide and close-up photos homing on this fascinating region rimmed by mountains and badlands have been relayed back to Earth by NASA’s New Horizons probe after last July’s flyby. For being only 1,473 miles (2,370 km) in diameter, Pluto displays an incredible diversity of landscapes.

Annotated version of Pluto's north polar region.
Annotated version showing sinuous valleys, canyons and depressions and irregular-shaped pits. Credit: NASA/JHUAPL/SRI with additional annotations by the author

This week, the New Horizons team shifted its focus northward, re-releasing an enhanced color image of the north polar area that was originally part of a high-resolution full-disk photograph of Pluto. Inside of the widest canyon, you can trace the sinuous outline of a narrower valley similar in outward appearance to the Moon’s Alpine Valleycut by a narrow, curvy rill that once served as a conduit for lava.

A composite of enhanced color images of Pluto (lower right) and Charon (upper left), taken by NASA's New Horizons spacecraft as it passed through the Pluto system on July 14, 2015. This image highlights the striking differences between Pluto and Charon. The color and brightness of both Pluto and Charon have been processed identically to allow direct comparison of their surface properties, and to highlight the similarity between Charon's polar red terrain and Pluto's equatorial red terrain. Pluto and Charon are shown with approximately correct relative sizes, but their true separation is not to scale.
A composite of enhanced color images of Pluto (lower right) and Charon, taken by NASA’s New Horizons spacecraft on July 14, 2015. This image highlights the striking differences between Pluto and Charon. The color and brightness of both Pluto and Charon have been processed identically to allow direct comparison of their surface properties, and to highlight the similarity between Charon’s polar red terrain and Pluto’s equatorial red terrain. Pluto and Charon are shown with approximately correct relative sizes, but their separation is not to scale. Credit: NASA/JHUAPL/SRI

We see multiple canyons in Pluto’s polar region, their walls broken and degraded compared to canyons seen elsewhere on the planet. Signs that they may be older and made of weaker materials and likely formed in ancient times when Pluto was more tectonically active. Perhaps they’re related to that long-ago dance between Pluto and its largest moon Charon as the two transitioned into their current tidally-locked embrace.

Cropped version showing three, odd-shaped pits that may reflect sinking of Pluto's crust. Credit:
Cropped version with arrows pointing to three, odd-shaped pits that may reflect sinking of Pluto’s crust. Credit: NASA/JHUAPL/SRI

In the lower right corner of the image, check out those funky-shaped pits that resemble the melting outlines of boot prints in the snow. They reach 45 miles (70 km) across and 2.5 miles (4 km) deep and may indicate locations where subsurface ice has melted or sublimated (vaporized) from below, causing the ground to collapse.

Notice the variation in color across the landscape from yellow-orange to pale blue. High elevations show up in a distinctive yellow, not seen elsewhere on Pluto, with lower elevations and latitudes a bluish gray. New Horizons’ infrared measurements show abundant methane ice across the Lowell Region, with relatively little nitrogen ice. The yellow terrains may be older methane deposits that have been more processed by solar UV light than the bluer terrain. The color variations are especially striking in the area of the collapse pits.

The new map shows exposed water ice to be considerably more widespread across Pluto's surface than was previously known - an important discovery.
The new map shows exposed water ice at Pluto to be considerably more widespread across its surface than was previously known. Its greatest concentration lies in the red-hued regions (in visual light) to the west of Tombaugh Regio, the large, heart-shaped feature. Credit: NASA/JHUAPL/SRI

Pluto’s icy riches include not only methane and nitrogen but also water, which forms the planet’s bedrock. NASA poetically refers to the water ice as “the canvas on which (Pluto’s) more volatile ices paint their seasonally changing patterns”. Recent images made in infrared light shows little or no water ice in the informally named places called Sputnik Planum (the left or western region of Pluto’s “heart”) and Lowell Regio. This indicates that at least in these regions, Pluto’s bedrock remains well hidden beneath a thick blanket of other ices such as methane, nitrogen and carbon monoxide.

To delve more deeply into Pluto, visit the NASA’s photojournal archive, where you’ll find 130 photos (and counting!) of the dwarf planet and its satellites.