Hubble Images Three Debris Disks Around G-type Stars

An image of the circum-stellar disk around HD 207129. The three circled objects are background objects and part of the disk. Image: Hubble Space Telescope, Glenn Schneider et al 2016.

A team using the Hubble Space Telescope has imaged circumstellar disk structures (CDSs) around three stars similar to our Sun. The stars are all G-type solar analogs, and the disks themselves share similarities with our Solar System’s own Kuiper Belt. Studying these CDSs will help us better understand their ring-like structure, and the formation of solar systems.

The team behind the study was led by Glenn Schneider of the Seward Observatory at the University of Arizona. They used the Hubble’s Space Telescope Imaging Spectrograph to capture the images. The stars in the study are HD 207917, HD 207129, and HD 202628.

Theoretical models of circumstellar disk dynamics suggest the presence of CDSs. Direct observation confirms their presence, though not many of these disks are within observational range. These new deep images of three solar analog CDSs are important. Studying the structure of these rings should lead to a better understanding of the formation of solar systems themselves.

A is the observed image of HD 207917. B is the best-fit debris ring model of the same star. Image: Hubble, G. Schneider et. al. 2016.
A is the observed image of HD 207917. B is the best-fit debris ring model of the same star. Image: Hubble, G. Schneider et. al. 2016.

Debris disks like these are separate from protoplanetary disks. Protoplanetary disks are a mixture of both gas and dust which exist around younger stars. They are the source material out of which planetesimals form. Those planetesimals then become planets.

Protoplanetary disks are much shorter-lived than CDSs. Whatever material is left over after planet formation is typically expelled from the host solar system by the star’s radiation pressure.

In circumstellar debris disks like the ones imaged in this study, the solar system is older, and the planets have already formed. CDSs like these have lasted this long by replenishing themselves. Collisions between larger bodies in the solar system create more debris. The resulting debris is continually ground down to smaller sizes by repeated collisions.

This process requires gravitational perturbation, either from planets in the system, or by binary stars. In fact, the presence of a CDSs is a strong hint that the solar system contains terrestrial planets.

A circumstellar disk of debris around a mature stellar system could indicate the presence of Earth-like planets. Credit: NASA/JPL
A circumstellar disk of debris around a mature stellar system could indicate the presence of Earth-like planets. Credit: NASA/JPL

The three disks in this study were viewed at intermediate inclinations. They scatter starlight, and are more easily observed than edge-on disks. Each of the three circumstellar disk structures possess “ring-like components that are more massive analogs of our solar system’s Edgeworth–Kuiper Belt,” according to the study.

The study authors expect that the images of these three disk structures will be studied in more detail, both by themselves and by others in future research. They also say that the James Webb Space Telescope will be a powerful tool for examining CDSs.

Read more: It’s Complicated: Hubble Survey Finds Unexpected Diversity in Dusty Discs Around Nearby Stars

New Horizons Spies Pluto’s Neighbor Quaoar

Now more than a year after its historic flyby of Pluto, the New Horizons spacecraft continues to speed through the Kuiper Belt. It’s currently on a beeline towards its next target of exploration, a KBO called 2014 MU69. But during its travels, New Horizons spotted another KBO, one of Pluto’s pals, Quaoar.

This animated sequence shows composite images of the Kuiper Belt object Quaoar, taken by New Horizons’ Long Range Reconnaissance Imager (LORRI). Click on the image to animate. Credit: NASA/JHUAPL/SwRI.
This animated sequence shows composite images of the Kuiper Belt object Quaoar, taken by New Horizons’ Long Range Reconnaissance Imager (LORRI). Click on the image to animate. Credit: NASA/JHUAPL/SwRI.

When these images were taken (in July 2016), Quaoar was approximately 4 billion miles (6.4 billion kilometers) from the Sun and 1.3 billion miles (2.1 billion kilometers) from New Horizons.

The animated sequence, above, (click the image if it isn’t animating in your browser) shows composite images taken by New Horizons’ Long Range Reconnaissance Imager (LORRI) at four different times over July 13-14: “A” on July 13 at 02:00 Universal Time; “B” on July 13 at 04:08 UT; “C” on July 14 at 00:06 UT; and “D” on July 14 at 02:18 UT. The New Horizons team explained that each composite includes 24 individual LORRI images, providing a total exposure time of 239 seconds and making the faint object easier to see.

Quaoar ( pronounced like “Kwa-war”) is about 690 miles or 1,100 kilometers in diameter, about half the size of Pluto. It was discovered on June 4, 2002 by astronomers Mike Brown and Chad Trujillo from Caltech, and at the time of its discovery, it was the largest object found in the Solar System since the discovery of Pluto. Quaoar’s discovery was one of the things that spurred the discussion of whether Pluto should continue to be classified as a planet or not.

But Quaoar is an interesting object in its own right and the New Horizons team said the oblique views of it that New Horizons can see – where LORRI sees only a portion of Quaoar’s illuminated surface — is very different from the nearly fully illuminated view of it that is visible from Earth. Comparing Quaoar from the two very different perspectives gives mission scientists a valuable opportunity to study the light-scattering properties of Quaoar’s surface.

If you’re thinking, “Why don’t we send a mission to Quaoar, or Sedna or Eris?” you aren’t alone. New Horizons team member Alex Parker has obviously been thinking about it. Parker tweeted that for a New Horizons-like mission it would take about 13 and a half years to reach Quaoar if it could be launched in December 2016. “Otherwise, we have to wait another 11 years for the next Jupiter assist window,” he said.

Um, NASA, can we put this on the schedule for 2027?

In the meantime, the images and data that New Horizons gathered during the Pluto flyby in July 2015 are still trickling back to Earth. The image below is a stunning view of Pluto’s methane snowcaps, visible at the terminator, showing the region north of Pluto’s dark equatorial band informally named Cthulhu Regio, and southwest of the vast nitrogen ice plains informally named Sputnik Planitia. This image was taken about 45 minutes before New Horizons’ closest approach to Pluto on July 14, 2015.

This area is south of Pluto's dark equatorial band informally named Cthulhu Regio, and southwest of the vast nitrogen ice plains informally named Sputnik Planitia. North is at the top; in the western portion of the image, a chain of bright mountains extends north into Cthulhu Regio. New Horizons compositional data indicate the bright snowcap material covering these mountains isn't water, but atmospheric methane that has condensed as frost onto these surfaces at high elevation. Between some mountains are sharply cut valleys – indicated by the white arrows. These valleys are each a few miles across and tens of miles long. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.
This area is south of Pluto’s dark equatorial band informally named Cthulhu Regio, and southwest of the vast nitrogen ice plains informally named Sputnik Planitia. North is at the top; in the western portion of the image, a chain of bright mountains extends north into Cthulhu Regio. New Horizons compositional data indicate the bright snowcap material covering these mountains isn’t water, but atmospheric methane that has condensed as frost onto these surfaces at high elevation. Between some mountains are sharply cut valleys – indicated by the white arrows. These valleys are each a few miles across and tens of miles long. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

See all of the latest photos sent back from our robot in the outer reaches of our Solar System at the New Horizons website.

NASA Approves New Horizons Extended KBO Mission, Keeps Dawn at Ceres

New Horizons trajectory and the orbits of Pluto and 2014 MU69.
New Horizons trajectory and the orbits of Pluto and 2014 MU69.

In an ‘Independence Day’ gift to a slew of US planetary research scientists, NASA has granted approval to nine ongoing missions to continue for another two years this holiday weekend.

The biggest news is that NASA green lighted a mission extension for the New Horizons probe to fly deeper into the Kuiper Belt and decided to keep the Dawn probe at Ceres forever, rather than dispatching it to a record breaking third main belt asteroid.

And the exciting extension news comes just as the agency’s Juno probe is about to ignite a do or die July 4 fireworks display to achieve orbit at Jupiter – detailed here.

“Mission approved!” the researchers gleefully reported on the probes Facebook and Twitter social media pages.

“Our extended mission into the #KuiperBelt has been approved. Thanks to everyone for following along & hopefully the best is yet to come.

Dwarf planet Ceres is shown in this false-color renderings, which highlight differences in surface materials.  The image is centered on Ceres brightest spots at Occator crater. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Dwarf planet Ceres is shown in this false-color renderings, which highlight differences in surface materials. The image is centered on Ceres brightest spots at Occator crater. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The New Horizons spacecraft will now continue on course in the Kuiper Belt towards an small object known as 2014 MU69, to carry out the most distant close encounter with a celestial object in human history.

“Here’s to continued success!”

The spacecraft will rendezvous with the ancient rock on New Year’s Day 2019.

Researchers say that 2014 MU69 is considered as one of the early building blocks of the solar system and as such will be invaluable to scientists studying the origin of our solar system how it evolved.

It was almost exactly one year ago on July 14, 2015 that New Horizons conducted Earth’s first ever up close flyby and science reconnaissance of Pluto – the most distant planet in our solar system and the last of the nine planets to be explored.

Pluto Explored at Last. The New Horizons mission team celebrates successful flyby of Pluto in the moments after closest approach at 7:49 a.m. EDT on July 14, 2015.   New Horizons Principal Investigator Alan Stern of Southwest Research Institute (SwRI), Boulder, CO., left, Johns Hopkins University Applied Physics Laboratory (APL) Director Ralph Semmel, center, and New Horizons Co-Investigator Will Grundy Lowell Observatory hold an enlarged print of an U.S. stamp with their suggested update after Pluto became the final planet in our solar system to be explored by an American space probe (crossing out the words ‘not yet’) - at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.  Credit: Ken Kremer/kenkremer.com
Pluto Explored at Last. The New Horizons mission team celebrates successful flyby of Pluto in the moments after closest approach at 7:49 a.m. EDT on July 14, 2015. New Horizons Principal Investigator Alan Stern of Southwest Research Institute (SwRI), Boulder, CO., left, Johns Hopkins University Applied Physics Laboratory (APL) Director Ralph Semmel, center, and New Horizons Co-Investigator Will Grundy Lowell Observatory hold an enlarged print of an U.S. stamp with their suggested update after Pluto became the final planet in our solar system to be explored by an American space probe (crossing out the words ‘not yet’) – at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. Credit: Ken Kremer/kenkremer.com

The immense volume of data gathered continues to stream back to Earth every day.

“The New Horizons mission to Pluto exceeded our expectations and even today the data from the spacecraft continue to surprise,” said NASA’s Director of Planetary Science Jim Green at NASA HQ in Washington, D.C.

“We’re excited to continue onward into the dark depths of the outer solar system to a science target that wasn’t even discovered when the spacecraft launched.”

This new global mosaic view of Pluto was created from the latest high-resolution images to be downlinked from NASA’s New Horizons spacecraft and released on Sept. 11, 2015. The images were taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). This new mosaic was stitched from over two dozen raw images captured by the LORRI imager and colorized. Annotated with informal place names. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Marco Di Lorenzo/Ken Kremer/kenkremer.com
This new global mosaic view of Pluto was created from the latest high-resolution images to be downlinked from NASA’s New Horizons spacecraft and released on Sept. 11, 2015. The images were taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). This new mosaic was stitched from over two dozen raw images captured by the LORRI imager and colorized. Annotated with informal place names. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Marco Di Lorenzo/Ken Kremer/kenkremer.com

While waiting for news on whether NASA would approve an extended mission, the New Horizons engineering and science team already ignited the main engine four times to carry out four course changes in October and November 2015, in order to preserve the option of the flyby past 2014 MU69 on Jan 1, 2019.

Green noted that mission extensions into fiscal years 2017 and 2018 are not final until Congress actually passes sufficient appropriation to fund NASA’s Planetary Science Division.

“Final decisions on mission extensions are contingent on the outcome of the annual budget process.”

Tough choices were made even tougher because the Obama Administration has cut funding for the Planetary Sciences Division – some of which was restored by a bipartisan majority in Congress for what many consider NASA’s ‘crown jewels.’

NASA’s Dawn asteroid orbiter just completed its primary mission at dwarf planet Ceres on June 30, just in time for the global celebration known as Asteroid Day.

“The mission exceeded all expectations originally set for its exploration of protoplanet Vesta and dwarf planet Ceres,” said NASA officials.

The Dawn science team had recently submitted a proposal to break out of orbit around the middle of this month in order to this conduct a flyby of the main belt asteroid Adeona.

Green declined to approve the Dawn proposal, citing additional valuable science to be gathered at Ceres.

The long-term monitoring of Ceres, particularly as it gets closer to perihelion – the part of its orbit with the shortest distance to the sun — has the potential to provide more significant science discoveries than a flyby of Adeona,” he said.

The funding required for a multi-year mission to Adeona would be difficult in these cost constrained times.

However the spacecraft is in excellent shape and the trio of science instruments are in excellent health.

Dawn arrived at Ceres on March 6, 2015 and has been conducting unprecedented investigation ever since.

Dawn is Earth’s first probe in human history to explore any dwarf planet, the first to explore Ceres up close and the first to orbit two celestial bodies.

The asteroid Vesta was Dawn’s first orbital target where it conducted extensive observations of the bizarre world for over a year in 2011 and 2012.

The mission is expected to last until at least later into 2016, and possibly longer, depending upon fuel reserves.

Due to expert engineering and handling by the Dawn mission team, the probe unexpectedly has hydrazine maneuvering fuel leftover.

Dawn will remain at its current altitude at the Low Altitude Mapping Orbit (LAMO) for the rest of its mission, and indefinitely afterward, even when no further communications are possible.

Green based his decision on the mission extensions on the biannual peer review scientific assessment by the Senior Review Panel.

Dawn was launched in September 2007.

The other mission extensions – contingent on available resources – are: the Mars Reconnaissance Orbiter (MRO), Mars Atmosphere and Volatile EvolutioN (MAVEN), the Opportunity and Curiosity Mars rovers, the Mars Odyssey orbiter, the Lunar Reconnaissance Orbiter (LRO), and NASA’s support for the European Space Agency’s Mars Express mission.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

New Horizons Sends Back First Science On Distant Kuiper Belt Object

This artist's impression shows the New Horizons spacecraft encountering a Pluto-like object in the distant Kuiper Belt. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Steve Gribben)

Even the most curmudgeonly anti-space troll has to admit that the New Horizons mission to Pluto has been an overwhelming success.

It’s not like New Horizons discovered life or anything, but it did bring an otherwise cold, distant lump to life for humanity. Vivid images and detailed scientific data revealed Pluto as a dynamic, changing world, with an active surface and an atmosphere. And we haven’t even received all of the data from New Horizons’ mission to Pluto yet.

Fresh off its historic visit to Pluto, New Horizons is headed for the Kuiper Belt, and just sent back its first science on one of the denizens of the distant belt of objects. The target in this case is 1994 JR1, a 145 km (90 mi.) wide Kuiper Belt Object (KBO). that orbits the Sun at a distance greater than 5 billion km. (3 billion mi.) New Horizons has now observed 1994 JR1 twice, and the team behind the mission has garnered new insights into this KBO based on these observations.

The spacecraft’s Long Range Reconnaissance Imager (LORRI) captured images of 1994 JR1 on April 7th-8th from a distance of 111 million km. (69 million mi.). That’s far closer than the images New Horizons captured in November 2015 from a distance of 280 million km (170 million miles).

This image, taken with the LORRI instrument aboard New Horizons, shows 2 of the 20 images captured in April. The moving dots are 1994 JR1, shown against a backdrop of stationary stars. The circular object in the top left of the image is a reflective artifact of the camera itself, showing LORRI's three support arms. Image: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
This image, taken with the LORRI instrument aboard New Horizons, shows 2 of the 20 images captured in April. The moving dots are 1994 JR1, shown against a backdrop of stationary stars. The circular object in the top left of the image is a reflective artifact of the camera itself, showing LORRI’s three support arms. Image: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

New Horizons science team member Simon Porter, of the Southwest Research Institute (SwRI) in Boulder Colorado, commented on the importance of these images. “Combining the November 2015 and April 2016 observations allows us to pinpoint the location of JR1 to within 1,000 kilometers (about 600 miles), far better than any small KBO,” Porter said.

Porter added that this accurate measurement of the KBO’s orbit allows New Horizons science team members to quash the idea that JR1 is a quasi-satellite of Pluto.

The team was also able to determine, by measuring the light reflected from the surface, that JR1’s rotational period is only 5.4 hours. That’s fast for a KBO. John Spencer, another New Horizons science team member from SwRI, said “This is all part of the excitement of exploring new places and seeing things never seen before.”

Variations in the brightness of light reflected from the  surface of 1994 JR1 allowed science team members to pinpoint the object's  rotation period at 5.4 hours.    Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Variations in the brightness of light reflected from the surface of 1994 JR1 allowed science team members to pinpoint the object’s rotation period at 5.4 hours.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

KBOs are ancient remnants of the early days of the Solar System. Whereas the inner regions of the Solar System were largely swept clean as the planets formed, the Kuiper Belt remained mostly as it is, untouched by the gravity of the planets.

There are trillions of objects in this cold, distant part of the Solar System. The Kuiper Belt itself spans a distance that is 30 to 50 times greater than the distance from the Earth to the Sun. It’s similar to the asteroid belt between Mars and Jupiter, but Kuiper Belt objects are icy, whereas asteroid belt objects are rocky, for the most part.

The New Horizons team has requested a mission extension, and if that extension is approved, the target is already chosen. In August 2015, NASA selected the KBO 2014 MU69, which resides in an orbit almost a billion miles beyond Pluto. There were two potential destinations for the spacecraft after it departed Pluto, and 2014 MU69 was recommended by the New Horizons team, and chosen by NASA.

If New Horizons' mission is extended, this is the path it will take to its next destination, 2014 MU69. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Alex Parker)
If New Horizons’ mission is extended, this is the path it will take to its next destination, 2014 MU69. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Alex Parker)

Choosing New Horizons’ next target early was important for fuel use. Fuel conservation allows the spacecraft to perform the maneuvers necessary to reach 2014 MU69. If all goes well, New Horizons should reach its next target by January 2019.

According to Alan Stern, New Horizons Principal Investigator, there are good reasons to visit 2014 MU69. “2014 MU69 is a great choice because it is just the kind of ancient KBO, formed where it orbits now, that the Decadal Survey desired us to fly by,” he said. “Moreover, this KBO costs less fuel to reach [than other candidate targets], leaving more fuel for the flyby, for ancillary science, and greater fuel reserves to protect against the unforeseen.”

The Decadal Survey in 2003 strongly recommended that flybys of Pluto and small KBOs should be conducted. The KBO is an unexplored region, and these flybys will allow us to sample the diversity of objects in the belt.

If New Horizons makes it to its next target, 2014 MU69, and delivers the types of results it has so far in its journey, it will be an unprecedented success. The kind of success that will make it harder and harder to be a curmudgeonly anti-space troll.

Wait. Who am I kidding.

Haters gonna hate.

Mysterious Pull On Cassini Probe May Help Find Planet Nine

Artist's impression of Planet Nine, blocking out the Milky Way. The Sun is in the distance, with the orbit of Neptune shown as a ring. Credit: ESO/Tomruen/nagualdesign

Finding a ninth planet in our Solar System this late in the game would be fascinating. It would also be somewhat of a surprise, considering our observational capabilities. But new evidence, in the form of small perturbations in the orbit of the Cassini probe, points to the existence of an as-yet undetected planet in our solar system.

Back in January, Konstantin Batygin and Mike Brown, two planetary scientists from the California Institute of Technology, presented evidence supporting the existence of a ninth planet. Their paper showed that some Kuiper Belt Objects (KBOs) display unexpected behaviour. It appears that 6 KBOs are affected by their relationship to a large object, but the KBOs in question are too distant from the known gas giants for them to be responsible. They think that a large, distant planet, in the distant reaches of our Solar System, could be responsible for the unexpected orbital clustering of these KBOs.

The calculated orbit of Planet Nine. Credit: Nature/K. Batygin and M. E. Brown Astronom. J. 151, 22 (2016
The calculated orbit of Planet Nine. Credit: Nature/K. Batygin and M. E. Brown Astronom. J. 151, 22 (2016)

Now, the Ninth Planet idea is gaining steam, and another team of researchers have presented evidence that small perturbations in the orbit of the Cassini spacecraft are caused by the new planet. Agnès Fienga at the Côte d’Azur Observatory in France, and her colleagues, have been working on a detailed model of the Solar System for over a decade. They plugged the hypothetical orbit and size of Planet Nine into their model, to see if it fit.

Planet Nine is calculated to be about 4 times as large as Earth, and 10 times as massive. It’s orbit takes between 10,000 and 20,000 years. A planet that large can only be hiding in so many places, and those places are a long way from Earth. Fienga found a potential home for Planet Nine, some 600 astronomical units (AU) from here. That much mass at that location could account for the perturbations in Cassini’s orbit.

There’s more good news when it comes to Planet Nine. By happy accident, it’s predicted location in the sky is towards the constellation Cetus, in the southern hemisphere. This means that it is in the view of the Dark Energy Survey, a southern hemisphere project that is studying the acceleration of the universe. The Dark Energy Survey is not designed to search for planetary objects, but it has successfully found at least one icy object.

There are other ways that the existence of Planet Nine could be confirmed. If it’s as large as thought, then it will radiate enough internal heat to be detected by instruments designed to study the Cosmic Microwave Background (CMB). There is also an enormous amount of data from multiple experiments and observations done over the years that might contain an inadvertent clue. But looking through it is an enormous task.

As for Brown and Batygin, who initially proposed the existence of Planet Nine based on the behaviour of KBOs, they are already proposing a more specific hunt for the elusive planet. They have asked for a substantial amount of observing time at the Subaru Telescope on Mauna Kea in Hawaii, in order to examine closely the location that Fienga’s solar system model predicts Planet Nine to be at.

For a more detailed look at Batygin’s and Brown’s work analyzing KBOs, read Matt Williams’ article here.

New Horizons Snaps Amazing 3-D View of Pluto’s Mysterious ‘Bladed’ Terrain

The amazing stereo view of a broad area informally named Tartarus Dorsa combines two images from the Ralph/Multispectral Visible Imaging Camera (MVIC) taken about 14 minutes apart on July 14, 2015. The first was taken when New Horizons was 16,000 miles (25,000 kilometers) away from Pluto, the second when the spacecraft was 10,000 miles (about 17,000 kilometers) away.   Credits: NASA/JHUAPL/SwRI
The amazing stereo view of a broad area informally named Tartarus Dorsa combines two images from the Ralph/Multispectral Visible Imaging Camera (MVIC) taken about 14 minutes apart on July 14, 2015. The first was taken when New Horizons was 16,000 miles (25,000 kilometers) away from Pluto, the second when the spacecraft was 10,000 miles (about 17,000 kilometers) away. Credits: NASA/JHUAPL/SwRI

It’s time to whip out your 3-D glasses to enjoy and scrutinize the remarkable detail of spectacular terrain revealed in a new high resolution stereo image of Pluto – King of the Kuiper Belt! – taken by NASA’s New Horizons spacecraft.

The amazing new stereo Plutonian image focuses on an area dominated by a mysterious feature that geologists call ‘bladed’ terrain – seen above – and its unlike anything seen elsewhere in our solar system.

Its located in a broad region of rough highlands informally known as Tartarus Dorsa – situated to the east of the Pluto’s huge heart shaped feature called Tombaugh Regio. The best resolution is approximately 1,000 feet (310 meters).

The stereo view combines a pair of images captured by New Horizons Ralph/Multispectral Visible Imaging Camera (MVIC) science instruments. They were taken about 14 minutes apart on during history making first ever flyby of the Pluto planetary system on July 14, 2015.

The first was taken when New Horizons was 16,000 miles (25,000 kilometers) away from Pluto, the second when the spacecraft was 10,000 miles (about 17,000 kilometers) away.

The blades align from north to south, typically reach up to about 550 yards (500 meters) high and are spaced about 2-4 miles (3-5 kilometers). Thus they are among the planets steepest features. They are “perched on a much broader set of rounded ridges that are separated by flat valley floors,” according to descriptions from the New Horizons science team.

This color image of Pluto taken by NASA’s New Horizons spacecraft shows rounded and bizarrely textured mountains, informally named the Tartarus Dorsa, rise up along Pluto’s terminator and show intricate but puzzling patterns of blue-gray ridges and reddish material in between. This view, roughly 330 miles (530 kilometers) across, combines blue, red and infrared images taken by the Ralph/Multispectral Visual Imaging Camera (MVIC) on July 14, 2015, and resolves details and colors on scales as small as 0.8 miles (1.3 kilometers).   Credits: NASA/JHUAPL/SWRI
This color image of Pluto taken by NASA’s New Horizons spacecraft shows rounded and bizarrely textured mountains, informally named the Tartarus Dorsa, rise up along Pluto’s terminator and show intricate but puzzling patterns of blue-gray ridges and reddish material in between. This view, roughly 330 miles (530 kilometers) across, combines blue, red and infrared images taken by the Ralph/Multispectral Visual Imaging Camera (MVIC) on July 14, 2015, and resolves details and colors on scales as small as 0.8 miles (1.3 kilometers). Credits: NASA/JHUAPL/SWRI

Mission scientists have also noted that the bladed terrain has the texture of “snakeskin” owing to their “scaly raised relief.”

In the companion global image from NASA (below), the bladed terrain is outlined in red and shown to extend quite far to the east of Tombaugh Regio.

The composite image was taken on July 13, 2015, the day before the closest approach flyby, when the probe was farther away thus shows lower resolution. It combines a pair of images from two of the science instruments – a Ralph/Multispectral Visible Imaging Camera (MVIC) color scan and an image from the Long Range Reconnaissance Imager (LORRI).

This global view of Pluto combines a Ralph/Multispectral Visible Imaging Camera (MVIC) color scan and an image from the Long Range Reconnaissance Imager (LORRI), both obtained on July 13, 2015 – the day before New Horizons’ closest approach. The red outline marks the large area of mysterious, bladed terrain extending from the eastern section of the large feature informally named Tombaugh Regio.  Credits: NASA/JHUAPL/SwRI
This global view of Pluto combines a Ralph/Multispectral Visible Imaging Camera (MVIC) color scan and an image from the Long Range Reconnaissance Imager (LORRI), both obtained on July 13, 2015 – the day before New Horizons’ closest approach. The red outline marks the large area of mysterious, bladed terrain extending from the eastern section of the large feature informally named Tombaugh Regio.
Credits: NASA/JHUAPL/SwRI

The MVIC scan was taken from a range of 1 million miles (1.6 million kilometers), at a resolution of 20 miles (32 kilometers) per pixel. The corresponding LORRI image was obtained from roughly the same range, but has a higher spatial resolution of 5 miles (8 kilometers) per pixel, say officials.

Scientists have developed several possible theories about the origins of the bladed terrain, including erosion from evaporating ices or deposition of methane ices.

Measurements from the Linear Etalon Imaging Spectral Array (LEISA) instrument reveal that that this region “is composed of methane (CH4) ice with a smattering of water,” reports New Horizons researcher Orkan Umurhan.

He speculates that “the material making up the bladed terrain is a methane clathrate. A clathrate is a structure in which a primary molecular species (say water, or H2O) forms a crystalline ‘cage’ to contain a guest molecule (methane or CH4, for example).”

But the question of whether that methane ice is strong enough to maintain the steep walled snakeskin features, will take much more research to determine a conclusive answer.

Umurhan suggests that more research could help determine if the “methane clathrates in the icy moons of the outer solar system and also in the Kuiper Belt were formed way back before the solar system formed – i.e., within the protosolar nebula – potentially making them probably some of the oldest materials in our solar system.”

Pluto continues to amaze and surprise us as the data streams back to eagerly waiting scientists on Earth over many more months to come – followed by years and decades of painstaking analysis.

This new global mosaic view of Pluto was created from the latest high-resolution images to be downlinked from NASA’s New Horizons spacecraft and released on Sept. 11, 2015. The images were taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). This new mosaic was stitched from over two dozen raw images captured by the LORRI imager and colorized. Annotated with informal place names. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Marco Di Lorenzo/Ken Kremer/kenkremer.com
This new global mosaic view of Pluto was created from the latest high-resolution images to be downlinked from NASA’s New Horizons spacecraft and released on Sept. 11, 2015. The images were taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). This new mosaic was stitched from over two dozen raw images captured by the LORRI imager and colorized. Annotated with informal place names. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Marco Di Lorenzo/Ken Kremer/kenkremer.com

During New Horizons flyby on July 14, 2015, it discovered that Pluto is the biggest object in the outer solar system and thus the ‘King of the Kuiper Belt.”

The Kuiper Belt comprises the third and outermost region of worlds in our solar system.

Pluto is the last planet in our solar system to be visited in the initial reconnaissance of planets by spacecraft from Earth since the dawn of the Space Age.

New Horizons remains on target to fly by a second Kuiper Belt Object (KBO) on Jan. 1, 2019 – tentatively named PT1, for Potential Target 1. It is much smaller than Pluto and was recently selected based on images taken by NASA’s Hubble Space Telescope.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

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Learn more about NASA Mars rovers, Orion, SLS, ISS, Orbital ATK, ULA, SpaceX, Boeing, Space Taxis, NASA missions and more at Ken’s upcoming outreach events:

Apr 9/10: “NASA and the Road to Mars Human Spaceflight programs” and “Curiosity explores Mars” at NEAF (NorthEast Astronomy and Space Forum), 9 AM to 5 PM, Suffern, NY, Rockland Community College and Rockland Astronomy Club – http://rocklandastronomy.com/neaf.html

Apr 12: Hosting Dr. Jim Green, NASA, Director Planetary Science, for a Planetary sciences talk about “Ceres, Pluto and Planet X” at Princeton University; 7:30 PM, Amateur Astronomers Assoc of Princeton, Peyton Hall, Princeton, NJ – http://www.princetonastronomy.org/

Apr 17: “NASA and the Road to Mars Human Spaceflight programs”- 1:30 PM at Washington Crossing State Park, Nature Center, Titusville, NJ – http://www.state.nj.us/dep/parksandforests/parks/washcros.html

Kuiper Belt Objects Point The Way To Planet 9

Artist's impression of Planet Nine, blocking out the Milky Way. The Sun is in the distance, with the orbit of Neptune shown as a ring. Credit: ESO/Tomruen/nagualdesign

On January 20th, 2016, researchers Konstantin Batygin and Michael E. Brown of Caltech announced that they had found evidence that hinted at the existence of a massive planet at the edge of the Solar System. Based on mathematical modeling and computer simulations, they predicted that this planet would be a super-Earth, two to four times Earth’s size and 10 times as massive. They also estimated that, given its distance and highly elliptical orbit, it would take 10,000 – 20,000 years to orbit the Sun.

Since that time, many researchers have responded with their own studies about the possible existence of this mysterious “Planet 9”. One of the latest comes from the University of Arizona, where a research team from the Lunar and Planetary Laboratory have indicated that the extreme eccentricity of distant Kuiper Belt Objects (KBOs) might indicate that they crossed paths with a massive planet in the past.

For some time now, it has been understood that there are a few known KBOs who’s dynamics are different than those of other belt objects. Whereas most are significantly controlled by the gravity of the gas giants planets in their current orbits (particularly Neptune), certain members of the scattered disk population of the Kuiper Belt have unusually closely-spaced orbits.

The six most distant known objects in the solar system with orbits exclusively beyond Neptune (magenta), including Sedna (dark magenta), all mysteriously line up in a single direction. Also, when viewed in three dimensions, they tilt nearly identically away from the plane of the solar system. Another population of Kuiper belt objects (cyan) are forced into orbits that are perpendicular to the plane of the solar system and clustered in orientation. Batygin and Brown show that a planet with 10 times the mass of the earth in a distant eccentric orbit (orange) anti-aligned with the magenta orbits and perpendicular to the cyan orbits is required to maintain this configuration. Credit: Caltech/R. Hurt (IPAC)
The orbits of Neptune (magenta), Sedna (dark magenta), a series of Kuiper belt objects (cyan), and the hypothetical Planet 9 (orange). Credit: Caltech/R. Hurt (IPAC)

When Batygin and Brown first announced their findings back in January, they indicated that these objects instead appeared to be highly clustered with respect to their perihelion positions and orbital planes. What’s more, their calculation showed that the odds of this being a chance occurrence were extremely low (they calculated a probability of 0.007%).

Instead, they theorized that it was a distant eccentric planet that was responsible for maintaining the orbits of these KBOs. In order to do this, the planet in question would have to be over ten times as massive as Earth, and have an orbit that lay roughly on the same plane (but with a perihelion oriented 180° away from those of the KBOs).

Such a planet not only offered an explanation for the presence of high-perihelion Sedna-like objects – i.e. planetoids that have extremely eccentric orbits around the Sun. It would also help to explain where distant and highly inclined objects in the outer Solar System come from, since their origins have been unclear up until this point.

In a paper titled “Coralling a distant planet with extreme resonant Kuiper belt objects“, the University of Arizona research team – which included Professor Renu Malhotra, Dr. Kathryn Volk, and Xianyu Wang – looked at things from another angle. If in fact Planet 9 were crossing paths with certain high-eccentricity KBOs, they reasoned, it was a good bet that its orbit was in resonance with these objects.

Pluto and its cohorts in the icy-asteroid-rich Kuiper Belt beyond the orbit of Neptune. Credit: NASA
Pluto and its cohorts in the icy-asteroid-rich Kuiper Belt beyond the orbit of Neptune. Credit: NASA

To break it down, small bodies are ejected  from the Solar System all the time due to encounters with larger objects that perturb their orbits. In order to avoid being ejected, smaller bodies need to be protected by orbital resonances. While the smaller and larger objects may pass within each others’ orbital path, they are never close enough that they would able to exert a significant influence on each other.

This is how Pluto has remained a part of the Solar System, despite having an eccentric orbit that periodically cross Neptune’s path. Though Neptune and Pluto cross each others orbit, they are never close enough to each other that Neptune’s influence would force Pluto out of our Solar System. Using this same reasoning, they hypothesized that the KBOs examined by Batygin and Brown might be in an orbital resonance with the Planet 9.

As Dr.  Malhotra, Volk and Wang told Universe Today via email:

“The extreme Kuiper belt objects we investigate in our paper are distinct from the others because they all have very distant, very elliptical orbits, but their closest approach to the Sun isn’t really close enough for them to meaningfully interact with Neptune. So we have these six observed objects whose orbits are currently fairly unaffected by the known planets in our Solar System. But if there’s another, as yet unobserved planet located a few hundred AU from the Sun, these six objects would be affected by that planet.”

After examining the orbital periods of these six KBOs – Sedna, 2010 GB174, 2004 VN112, 2012 VP113, and 2013 GP136 – they concluded that a hypothetical planet with an orbital period of about 17,117 years (or a semimajor axis of about 665 AU), would have the necessary period ratios with these four objects. This would fall within the parameters estimated by Batygin and Brown for the planet’s orbital period (10,000 – 20,000 years).

Animated diagram showing the spacing of the Solar Systems planet’s, the unusually closely spaced orbits of six of the most distant KBOs, and the possible “Planet 9”. Credit: Caltech/nagualdesign
Animated diagram showing the spacing of the Solar Systems planet’s, the unusually closely spaced orbits of six of the most distant KBOs, and the possible “Planet 9”. Credit: Caltech/nagualdesign

Their analysis also offered suggestions as to what kind of resonance the planet has with the KBOs in question. Whereas Sedna’s orbital period would have a 3:2 resonance with the planet, 2010 GB174 would be in a 5:2 resonance, 2994 VN112 in a 3:1, 2004 VP113 in 4:1, and 2013 GP136 in 9:1. These sort of resonances are simply not likely without the presence of a larger planet.

“For a resonance to be dynamically meaningful in the outer Solar System, you need one of the objects to have enough mass to have a reasonably strong gravitational effect on the other,” said the research team. “The extreme Kuiper belt objects aren’t really massive enough to be in resonances with each other, but the fact that their orbital periods fall along simple ratios might mean that they each are in resonance with a massive, unseen object.”

But what is perhaps most exciting is that their findings could help to narrow the range of Planet 9’s possible location. Since each orbital resonance provides a geometric relationship between the bodies involved, the resonant configurations of these KBOs can help point astronomers to the right spot in our Solar System to find it.

But of course, Malhotra and her colleagues freely admit that several unknowns remain, and further observation and study is necessary before Planet 9 can be confirmed:

“There are a lot of uncertainties here. The orbits of these extreme Kuiper belt objects are not very well known because they move very slowly on the sky and we’ve only observed very small portions of their orbital motion. So their orbital periods might differ from the current estimates, which could make some of them not resonant with the hypothetical planet. It could also just be chance that the orbital periods of the objects are related; we haven’t observed very many of these types of objects, so we have a limited set of data to work with.”

Based on a careful study of Saturn's orbit and using mathematical models, French scientists were able to whittle down the search region for Planet Nine to "possible" and "probable" zones. Source: CNRS, Cote d'Azur and Paris observatories. Credit:
Estimates of Planet Nine’s “possible” and “probable” zones. by French scientists based on a careful study of Saturn’s orbit and using mathematical models. Source: CNRS, Cote d’Azur and Paris observatories. Credit: Bob King

Ultimately, astronomers and the rest of us will simply have to wait on further observations and calculations. But in the meantime, I think we can all agree that the possibility of a 9th Planet is certainly an intriguing one! For those who grew up thinking that the Solar System had nine planets, these past few years (where Pluto was demoted and that number fell to eight) have been hard to swallow.

But with the possible confirmation of this Super-Earth at the outer edge of the Solar System, that number could be pushed back up to nine soon enough!

Further Reading: arXiv.org

New Horizons Takes Closest Image Ever of a Kuiper Belt Object

New Horizons’ Long Range Reconnaissance Imager (LORRI) took this image on Nov. 2, 2015 of a 90-mile (150-kilometer)-wide ancient Kuiper Belt Object named 1994 JR1, moving against a background of stars. Credit: NASA/JHUAPL/SwRI

The New Horizons spacecraft is already 209,437,000 km (130,138,000 miles) past Pluto (as of Dec. 4, 2015), making it 5,226,950,000 km (3,247,880,000 miles) from Earth. So, yes, it’s way out there. Recently, it took the closest images ever of a distant Kuiper Belt object, setting a record by a factor of at least 15, according to NASA. The team says this image demonstrates the spacecraft’s ability to observe numerous similar bodies over the next several years.
Continue reading “New Horizons Takes Closest Image Ever of a Kuiper Belt Object”

Who was Gerard Kuiper?

In the outer reaches of the Solar System, beyond the orbit of Neptune, lies a region permeated by celestial objects and minor planets. This region is known as the “Kuiper Belt“, and is named in honor of the 20th century astronomer who speculated about the existence of such a disc decades before it was observed. This disc, he reasoned, was the source of the Solar Systems many comets, and the reason there were no large planets beyond Neptune.

Gerard Kuiper is also regarded by many as being the “father of planetary science”. During the 1960s and 70s, he played a crucial role in the development of infrared airborne astronomy, a technology which led to many pivotal discoveries that would have been impossible using ground-based observatories. At the same time, he helped catalog asteroids, surveyed the Moon, Mars and the outer Solar System, and discovered new moons.

Continue reading “Who was Gerard Kuiper?”

Awesome Blue Skies and Red Surface Ice Found at Pluto – The Other Red Planet

Much to the amazement and delight of scientists, the latest findings about Pluto reveal it possesses hazy blue skies and numerous red colored patches of water ice exposed on the surface of a world also now known as “The Other Red Planet.”

With each passing day, significant discoveries about Pluto continue piling up higher and higher as more and more data gathered and stored from this past summer’s historic flyby by NASA’s New Horizons reaches ground stations back here on Earth.

“Blue skies–Pluto is awesome!” says Alan Stern, New Horizons principal investigator from Southwest Research Institute (SwRI), Boulder, Colorado.

The bluish tint to Pluto’s skies were unexpectedly discovered after researchers examined the first color images of the high altitude atmospheric hazes returned by New Horizons last week that were taken by the probes Ralph/Multispectral Visible Imaging Camera (MVIC).

“Who would have expected a blue sky in the Kuiper Belt?” Stern said in a NASA statement.

During New Horizons flyby on July 14, 2015, it discovered that Pluto is the biggest object in the outer solar system and thus the ‘King of the Kuiper Belt.”

The Kuiper Belt comprises the third and outermost region of worlds in our solar system.

“It’s gorgeous!” exclaims Stern.

Moreover, the source of Pluto’s blue haze is different from Earth’s and more related to Titan, Saturn’s largest moon – currently being explored by NASA’s Cassini mission orbiting Saturn since 2004.

On Earth, the blue sky is caused by light scattering off tiny particles of nitrogen molecules. Whereas on Titan its related to soot-like particles called tholins.

Tholins are generated by a series of very complex sunlight-initiated chemical reactions between nitrogen and methane (CH4) high in the atmosphere. This eventually produces relatively small, soot-like particles of complex hydrocarbons.

“That striking blue tint tells us about the size and composition of the haze particles,” said New Horizons science team researcher Carly Howett, of SwRI, in a statement.

“A blue sky often results from scattering of sunlight by very small particles. On Earth, those particles are very tiny nitrogen molecules. On Pluto they appear to be larger — but still relatively small — soot-like particles we call tholins.”

As the tholins rain down on Pluto, they add to the widespread red surface coloring.

The Ralph instrument was also key in another discovery announced by New Horizons researchers.

Numerous small, exposed regions of water ice on Pluto’s surface were discovered by combining measurements from the Ralph MVIC spectral composition mapper and infrared spectroscopy from the Linear Etalon Imaging Spectral Array (LEISA) instrument.

The strongest signatures of water ice were found in the Virgil Fossa and Viking Terra regions berby the western edge of Pluto’s huge heart-shaped Tombaugh Regio feature – see image below.

Water Ice on Pluto: Regions with exposed water ice are highlighted in blue in this composite image from New Horizons' Ralph instrument, combining visible imagery from the Multispectral Visible Imaging Camera (MVIC) with infrared spectroscopy from the Linear Etalon Imaging Spectral Array (LEISA). The strongest signatures of water ice occur along Virgil Fossa, just west of Elliot crater on the left side of the inset image, and also in Viking Terra near the top of the frame. A major outcrop also occurs in Baré Montes towards the right of the image, along with numerous much smaller outcrops, mostly associated with impact craters and valleys between mountains. The scene is approximately 280 miles (450 kilometers) across. Note that all surface feature names are informal.  Credits: NASA/JHUAPL/SwRI
Water Ice on Pluto: Regions with exposed water ice are highlighted in blue in this composite image from New Horizons’ Ralph instrument, combining visible imagery from the Multispectral Visible Imaging Camera (MVIC) with infrared spectroscopy from the Linear Etalon Imaging Spectral Array (LEISA). The strongest signatures of water ice occur along Virgil Fossa, just west of Elliot crater on the left side of the inset image, and also in Viking Terra near the top of the frame. A major outcrop also occurs in Baré Montes towards the right of the image, along with numerous much smaller outcrops, mostly associated with impact craters and valleys between mountains. The scene is approximately 280 miles (450 kilometers) across. Note that all surface feature names are informal. Credits: NASA/JHUAPL/SwRI

Water ice is only found in certain zones of Pluto for reasons yet to be understood. There may also be a relationship to the tholins, that likewise is yet to be gleaned.

“I’m surprised that this water ice is so red,” says Silvia Protopapa, a science team member from the University of Maryland, College Park. “We don’t yet understand the relationship between water ice and the reddish tholin colorants on Pluto’s surface.”

This new global mosaic view of Pluto was created from the latest high-resolution images to be downlinked from NASA’s New Horizons spacecraft and released on Sept. 11, 2015.   The images were taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers).  This new mosaic was stitched from over two dozen raw images captured by the LORRI imager and colorized.  Annotated with informal place names.  Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Marco Di Lorenzo/Ken Kremer/kenkremer.com
This new global mosaic view of Pluto was created from the latest high-resolution images to be downlinked from NASA’s New Horizons spacecraft and released on Sept. 11, 2015. The images were taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). This new mosaic was stitched from over two dozen raw images captured by the LORRI imager and colorized. Annotated with informal place names. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Marco Di Lorenzo/Ken Kremer/kenkremer.com

As of today, New Horizons remains healthy and is over 3.1 billion miles (5 billion kilometers) from Earth.

The team hopes to fire up the thrusters later this fall to propel the spacecraft toward a second Kuiper Belt Object (KBO) in 2019 tentativley named PT1, for Potential Target 1. It is much smaller than Pluto and was recently selected based on images taken by NASA’s Hubble Space Telescope.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer