Check out this wonderful time-lapse video from the project SKYGLOW, which includes great views of the night sky: A Meteorite Explodes Over the Mojave in This Incredible Timelapse Video – Gizmodo
A couple of other Skyglow videos:
Check out this wonderful time-lapse video from the project SKYGLOW, which includes great views of the night sky: A Meteorite Explodes Over the Mojave in This Incredible Timelapse Video – Gizmodo
A couple of other Skyglow videos:
Harvard College astrophysics student Nina Hooper gives a TEDx talk on the potential of asteroid mining: Spotlight TEDx Talk: How asteroid mining could help us live in space – TEDx Innovations Blog
Imagine a world with ubiquitous, affordable space travel, where getting in a spaceship is no stranger than getting in an airplane. Harvard undergraduate Nina Hooper, an astrophysics student, shows how mining asteroids for platinum could be the way to make space travel cheap and accessible to civilians.
Nina Hooper is a Harvard College student from Melbourne, Australia studying astrophysics. She loves traveling and adventure and is working towards what she believes is the ultimate adventure – going to space. She is also a private pilot, a songwriter and a major foodie. Nina intends to pursue a graduate degree in aerospace and astrospace engineering either in the US or UK.
The latest NASA “Space to Ground” report on activities related to the International Space Station:
Update: A TMRO Space Pod on ISS research: Why do we blow money on the International Space Station? – Space Pod 2/2/16 – TMRO
Former Canadian astronaut Robert Thirsk chats to TMRO correspondent Lisa Stojanovski about how International Space Station research benefits Earth and how it can inspire the next generation of astronauts.
The latest ESO (European Southern Observatory) report:
Astronomers have used the ALMA and IRAM telescopes to make the first direct measurement of the temperature of the large dust grains in the outer parts of a planet-forming disc around a young star. By applying a novel technique to observations of an object nicknamed the Flying Saucer they find that the grains are much colder than expected: −266 degrees Celsius. This surprising result suggests that models of these discs may need to be revised.
The international team, led by Stephane Guilloteau at the Laboratoire d’Astrophysique de Bordeaux, France, measured the temperature of large dust grains around the young star 2MASS J16281370-2431391 in the spectacular Rho Ophiuchi star formation region, about 400 light-years from Earth.
This star is surrounded by a disc of gas and dust — such discs are called protoplanetary discs as they are the early stages in the creation of planetary systems. This particular disc is seen nearly edge-on, and its appearance in visible light pictures has led to its being nicknamed the Flying Saucer.
The astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe the glow coming from carbon monoxide molecules in the 2MASS J16281370-2431391 disc. They were able to create very sharp images and found something strange — in some cases they saw a negative signal! Normally a negative signal is physically impossible, but in this case there is an explanation, which leads to a surprising conclusion.
This video takes us on a journey to the young star 2MASS J16281370-2431391 in the spectacular Rho Ophiuchi star formation region, about 400 light-years from Earth. This star is surrounded by a disc of gas and dust — a protoplanetary disc, the early stage in the creation of a planetary system. This particular disc is seen nearly edge-on, and its appearance in visible light pictures has led to its being nicknamed the Flying Saucer.
The final close-up infrared view of the Flying Saucer comes from the NASA/ESA Hubble Space Telescope.
Lead author Stephane Guilloteau takes up the story:
“This disc is not observed against a black and empty night sky. Instead it’s seen in silhouette in front of the glow of the Rho Ophiuchi Nebula. This diffuse glow is too extended to be detected by ALMA, but the disc absorbs it. The resulting negative signal means that parts of the disc are colder than the background. The Earth is quite literally in the shadow of the Flying Saucer!”
The team combined the ALMA measurements of the disc with observations of the background glow made with the IRAM 30-metre telescope in Spain . They derived a disc dust grain temperature of only −266 degrees Celsius (only 7 degrees above absolute zero, or 7 Kelvin) at a distance of about 15 billion kilometres from the central star . This is the first direct measurement of the temperature of large grains (with sizes of about one millimetre) in such objects.
This temperature is much lower than the −258 to −253 degrees Celsius (15 to 20 Kelvin) that most current models predict. To resolve the discrepancy, the large dust grains must have different properties than those currently assumed, to allow them to cool down to such low temperatures.
“To work out the impact of this discovery on disc structure, we have to find what plausible dust properties can result in such low temperatures. We have a few ideas — for example the temperature may depend on grain size, with the bigger grains cooler than the smaller ones. But it is too early to be sure,” adds co-author Emmanuel di Folco (Laboratoire d’Astrophysique de Bordeaux).
If these low dust temperatures are found to be a normal feature of protoplanetary discs this may have many consequences for understanding how they form and evolve.
For example, different dust properties will affect what happens when these particles collide, and thus their role in providing the seeds for planet formation. Whether the required change in dust properties is significant or not in this respect cannot yet be assessed.
Low dust temperatures can also have a major impact for the smaller dusty discs that are known to exist. If these discs are composed of mostly larger, but cooler, grains than is currently supposed, this would mean that these compact discs can be arbitrarily massive, so could still form giant planets comparatively close to the central star.
Further observations are needed, but it seems that the cooler dust found by ALMA may have significant consequences for the understanding of protoplanetary discs.
Here’s a sample:
Emily Lakdawalla at the Planetary Society talks about the images: Fun with a new data set: Chang’e 3 lander and Yutu rover camera data – The Planetary Society
The latest results from the New Horizons probe:
Data from NASA’s New Horizons spacecraft point to more prevalent water ice on Pluto’s surface than previously thought.
This false-color image, derived from observations in infrared light by the Ralph/Linear Etalon Imaging Spectral Array (LEISA) instrument, shows where the spectral features of water ice are abundant on Pluto’s surface. It is based on two LEISA scans of Pluto obtained on July 14, 2015, from a range of about 67,000 miles (108,000 kilometers).
The scans, taken about 15 minutes apart, were stitched into a combined multispectral Pluto “data cube” covering the full hemisphere visible to New Horizons as it flew past Pluto. A data cube like this is a three-dimensional array in which an image of Pluto is formed at each LEISA-sensitive wavelength.
Water ice is Pluto’s crustal “bedrock,” the canvas on which its more volatile ices paint their seasonally changing patterns. Initial New Horizons maps of Pluto’s water ice bedrock compared LEISA spectra with a pure water ice template spectrum, resulting in the map at left.
A disadvantage of that technique is that water ice’s spectral signature is easily masked by methane ice, so that map was only sensitive to areas that were especially rich in water ice and/or depleted in methane. The much more sensitive method used on the right involves modeling the contributions of Pluto’s various ices all together. This method, too, has limitations in that it can only map ices included in the model, but the team is continually adding more data and improving the model.
The new map shows exposed water ice to be considerably more widespread across Pluto’s surface than was previously known — an important discovery. But despite its much greater sensitivity, the map still 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 (far north on the encounter hemisphere). This indicates that at least in these regions, Pluto’s icy bedrock is well hidden beneath a thick blanket of other ices such as methane, nitrogen and carbon monoxide.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
This image from NASA’s New Horizons spacecraft is the first look at Pluto’s atmosphere in infrared wavelengths, and the first image of the atmosphere made with data from the New Horizons Ralph/Linear Etalon Imaging Spectral Array (LEISA) instrument.
In this image, sunlight is coming from above and behind Pluto. The image was captured on July 14, 2015, while New Horizons was about 112,000 miles (180,000 kilometers) away. The image covers LEISA’s full spectral range (1.25 to 2.5 microns), which is divided into thirds, with the shortest third being put into the blue channel, middle third into the green channel, and longest into the red channel. North in this image is around the 10 o’clock position.
The blue ring around Pluto is caused by sunlight scattering from haze particles common in Pluto’s atmosphere; scientists believe the haze is a photochemical smog resulting from the action of sunlight on methane and other molecules, producing a complex mixture of hydrocarbons such as acetylene and ethylene. These hydrocarbons accumulate into small particles – a fraction of a micrometer in size – which scatter sunlight to make the blue haze. The new infrared image, when combined with earlier images made at shorter, visible wavelengths, gives scientists new clues into the size distribution of the particles.
The whitish patches around Pluto’s limb in this image are sunlight bouncing off more reflective or smoother areas on Pluto’s surface – with the largest patch being the western section of the informally named Cthulhu Regio. Future LEISA observations returned to Earth should capture the remainder of the haze, missing from the lower section of the image.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.
This NASA JPL video points to highlights in the night sky for February:
Set your alarm! Five planets will be visible in the early morning sky until Feb. 20. Plus, learn what other celestial objects will be visible this month.
1. Monday, Feb. 1, 2016: 2-3:30 PM PST (5-6:30 PM EST; 4-5:30 PM CST): We welcome back DR. JOHN BRANDENBURG Mars update and his challenge for a debate.
2. Tuesday, Feb. 2, 2016,7-8:30 PM PST (10-11:30 PM EST, 9-10:30 PM CST): We welcome back ROBERT (BOB) ZIMMERMAN for space news updates and more.
4. Sunday, Feb., 2016: 12-1:30 PM PST (3-4:30 PM EST, 2-3:30 PM CST): We welcome back JIM FUNARO to tell us about the upcoming Contact Conference.
The Space Show is a project of the One Giant Leap Foundation.
The latest episode of the TMRO.tv live show is now in the archive: Is there such a thing as Safe Space travel? – TMRO
This week we ask the questions, “Is there such a thing as safe space travel? Than there ever be safe space travel? And would you fly to space now or after we make it safer?”
News topics examined:
* Belintersat 1 Launch via Long March 3B
* JASON-3 Launch via Falcon 9 1.1
* IRNSS 1E Launch via PSLV
* Intelsat 29e Launch via Ariane 5
* Drones Flying Out of Spaceport America
* Curiosity suffers a sampling system hiccup
* Blue Origin Update
* Recovered Falcon 9 booster fires again at Cape Canaveral
* Planet Nine? Not so fast… Planet X?
TMRO is viewer supported:
TMRO Live Shows are crowd funded. If you like this episode consider contributing to help us to continue to improve. Head over to http://www.patreon.com/tmro for information, goals and reward levels. Don’t forget to check out our SpacePod campaign as well over at http://www.patreon.com/spacepod
Here’s the latest Space to Ground report on activities related to the Int. Space Station this week:
The movie was produced by members of Dawn’s framing camera team at the German Aerospace Center, DLR, using images from Dawn’s high-altitude mapping orbit. During that phase of the mission, which lasted from August to October 2015, the spacecraft circled Ceres at an altitude of about 900 miles (1,450 kilometers).
“The simulated overflight shows the wide range of crater shapes that we have encountered on Ceres. The viewer can observe the sheer walls of the crater Occator, and also Dantu and Yalode, where the craters are a lot flatter,” said Ralf Jaumann, a Dawn mission scientist at DLR.
Dawn is the first mission to visit Ceres, the largest object in the main asteroid belt between Mars and Jupiter. After orbiting asteroid Vesta for 14 months in 2011 and 2012, Dawn arrived at Ceres in March 2015. The spacecraft is currently in its final and lowest mapping orbit, at about 240 miles (385 kilometers) from the surface.
Dawn’s mission is managed by the Jet Propulsion Laboratory for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants, visit:
Presented by Encompass New Opera Theatre
Breathtaking images of the galaxies and outer space ignite this modern tale of a young man who dreams of space travel and flying to Mars. Guided by a mysterious stranger who challenges his views on creation and fuels his desire to become an astronaut, the young man discovers romance and a drive to succeed, which catapults his blast off into space, transforming his life. With stunning projections, an exciting percussive score for chamber orchestra, and gorgeous vocal music, The Astronaut’s Tale is a luminous glimpse at a multidimensional universe and the majesty of outer space.
Music by Charles Fussell
Libretto by Jack Larson
Directed by Nancy Rhodes
Conducted by Nicholas DeMaison
Sets by Stephen H. Carmody
Projections by Lianne Arnold
Costumes by Angela Huff
Lighting by Sarah Johnston
Additional details about the work can be found at The Astronaut’s Tale – Encompass New Opera Theatre.
The end of January and the beginning of February bring anniversaries of US space program catastrophes. Today marks 30 years since the Space Shuttle Challenger disaster that led to the deaths of Francis R. Scobee, Michael J. Smith, Ronald McNair, Ellison Onizuka, Judith Resnik, Gregory Jarvis, and Christa McAuliffe.
And next Monday, Feb. 1st, will mark the 13th anniversary of the Space Shuttle Columbia disaster in which Rick D. Husband, William C. McCool, Michael P. Anderson, Kalpana Chawla, David M. Brown, Laurel Clark, and Ilan Ramon were killed.
ESO (European Southern Oberservatory) has a new report out:
Many galaxies are chock-full of dust, while others have occasional dark streaks of opaque cosmic soot swirling in amongst their gas and stars. However, the subject of this new image, snapped with the OmegaCAM camera on ESO’s VLT Survey Telescope in Chile, is unusual — the small galaxy, named IC 1613, is a veritable clean freak! IC 1613 contains very little cosmic dust, allowing astronomers to explore its contents with great clarity. This is not just a matter of appearances; the galaxy’s cleanliness is vital to our understanding of the Universe around us.Max Wolf discovered IC 1613’s faint glow in 1906. In 1928, his compatriot Walter Baade used the more powerful 2.5-metre telescope at the Mount Wilson Observatory in California to successfully make out its individual stars. From these observations, astronomers figured out that the galaxy must be quite close to the Milky Way, as it is only possible to resolve single pinprick-like stars in the very nearest galaxies to us.
Astronomers have since confirmed that IC 1613 is indeed a member of the Local Group, a collection of more than 50 galaxies that includes our home galaxy, the Milky Way. IC 1613 itself lies just over 2.3 million light-years away from us. It is relatively well-studied due to its proximity; astronomers have found it to be an irregular dwarf that lacks many of the features, such as a starry disc, found in some other diminutive galaxies.
This sequence starts with a broad view of the rather faint constellation of Cetus (The Sea Monster). As we zoom, we close in on a faint, but nearby galaxy, IC 1613. The final detailed image, captured with the OmegaCAM camera on ESO’s VLT Survey Telescope in Chile, shows an unusually clean small galaxy. IC 1613 contains very little cosmic dust, allowing astronomers to explore its contents with great clarity. Credit: ESO/A. Fujii/Digitised Sky Survey 2. Music: Johan B. Monell (www.johanmonell.com)
However, what IC 1613 lacks in form, it makes up for in tidiness. We know IC 1613’s distance to a remarkably high precision, partly due to the unusually low levels of dust lying both within the galaxy and along the line of sight from the Milky Way — something that enables much clearer observations .
The second reason we know the distance to IC 1613 so precisely is that the galaxy hosts a number of notable stars of two types: Cepheid variables and RR Lyrae variables . Both types of star rhythmically pulsate, growing characteristically bigger and brighter at fixed intervals (eso1311).
As we know from our daily lives on Earth, shining objects such as light bulbs or candle flames appear dimmer the further they are away from us. Astronomers can use this simple piece of logic to figure out exactly how far away things are in the Universe— so long as they know how bright they really are, referred to as their intrinsic brightness.
Cepheid and RR Lyrae variables have the special property that their period of brightening and dimming is linked directly to their intrinsic brightness. So, by measuring how quickly they fluctuate astronomers can work out their intrinsic brightness. They can then compare these values to their apparent measured brightness and work out how far away they must be to appear as dim as they do.
Stars of known intrinsic brightness can act like standard candles, as astronomers say, much like how a candle with a specific brightness would act as a good gauge of distance intervals based on the observed brightness of its flame’s flicker.
Using standard candles — such as the variable stars within IC 1613 and the less-common Type Ia supernova explosions, which can seen across far greater cosmic distances — astronomers have pieced together a cosmic distance ladder, reaching deeper and deeper into space.
Decades ago, IC 1613 helped astronomers work out how to utilise variable stars to chart the Universe’s grand expanse. Not bad for a little, shapeless galaxy.
This video sequence takes a close look at a new image, captured with the OmegaCAM camera on ESO’s VLT Survey Telescope in Chile, showing an unusually clean small galaxy. IC 1613 contains very little cosmic dust, allowing astronomers to explore its contents with great clarity. Credit: ESO. Music: Johan B. Monell (www.johanmonell.com)
 OmegaCAM is a 32-CCD, 256-million-pixel camera mounted on the 2.6-metre VLT Survey Telescope at Paranal Observatory in Chile. Click here to view more images taken by OmegaCAM.
 Cosmic dust is made of various heavier elements, such as carbon and iron, as well as larger, grainier molecules. Not only does dust block out light, making dust-shrouded objects harder to see, it also preferentially scatters bluer light. As a result, cosmic dust makes objects appear redder when seen through our telescopes than they are in reality. Astronomers can factor out this reddening when studying objects. Still, the less reddening, the more precise an observation is likely to be.
 Other than the two Magellanic Clouds, IC 1613 is the only irregular dwarf galaxy in the Local Group in which RR Lyrae type variable stars have been identified.
1. Monday, January 25, 2016: 2-3:30 PM PST (5-6:30 PM EST; 4-5:30 PM CST): This is an Indiegogo Co-Host Perk Show featuring TOM MAROTTA with his two guests, CHARLES MILLER and JOSHUA JENKINS. Their topic is March Storm 2016.
3.SPECIAL TIME: Friday, January 29, 2016, 2016; 2-3:30 PM PST (5-6:30 PM EST; 4-5:30 PM CST) We welcome back FRANK WHITE with STEVE ROITFELD of Steve Roitfeld Productions to discuss The Overview Effect and the film about the subject.
4. Sunday, Jan. 31, 2016: 12-1:30 PM PST (3-4:30 PM EST, 2-3:30 PM CST): OPEN LINES. All space and STEM topics are welcome. First time callers are welcome and wanted.
The Space Show is a project of the One Giant Leap Foundation.
Here’s a cool time-lapse video of satellite imagery showing the big snow storm over the east coast: NASA’s GEOS-5 provides a satellite view of historic winter storm – Global Modeling and Assimilation Office Research Site
This one is from NOAA:
Here’s a sat image of the blizzard during Saturday morning (Jan.23rd): 2016 Blizzard by Moonlight – NASA
A massive winter storm system pummeled the eastern United States in late January 2016, with two low-pressure systems merging into a potent nor’easter that dropped heavy snow from Virginia to New England. By late afternoon on Jan. 23, snowfall totals were approaching records in several states, and hurricane-force winds were battering the coastlines and leading to serious flooding. The storm was expected to continue through the morning of Jan. 24.
The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite acquired this image of the storm system at 2:15 a.m. EST on Jan. 23. It was composed through the use of the VIIRS “day-night band,” which detects faint light signals such as city lights, moonlight, airglow, and auroras. In the image, the clouds are lit from above by the nearly full Moon and from below by the lights of the heavily populated East Coast. The city lights are blurred in places by cloud cover.
Here’s an image of the storm as seen from the space station: Scott Kelly on Twitter:
“Massive #snowstorm blanketing #EastCoast clearly visible from @Space_Station! Stay safe! #blizzard2016 #YearInSpace”
And here is a satellite image showing the East Coast this morning after the clouds have cleared: NASA Sees Dawn and Records Breaking as Major Winter Storm Departs -NASA
The latest NASA report on activities related to the Int. Space Station:
A cool “liquid ping-pong” demo on the station:
A couple of commercial program developments at KSC:
The NASA/ESA Hubble Telescope collaboration releases this report about a beautiful cluster of bright young stars:
Single stars are often overlooked in favour of their larger cosmic cousins — but when they join forces, they create truly breathtaking scenes to rival even the most glowing of nebulae or swirling of galaxies. This NASA/ESA Hubble Space Telescope image features the star cluster Trumpler 14. One of the largest gatherings of hot, massive and bright stars in the Milky Way, this cluster houses some of the most luminous stars in our entire galaxy.
Around 1100 open clusters have so far been discovered within the Milky Way, although many more are thought to exist. Trumpler 14 is one of these, located some 8000 light-years away towards the centre of the well-known Carina Nebula.
This short sequence zooms in on the open young cluster of stars, Trumpler 14. One of the largest gatherings of hot, massive and bright stars in the Milky Way, this cluster houses some of the most luminous stars in our entire galaxy. Credit: ESO, DSS, ESA/Hubble, Risinger (skysurvey.org) Music: Johan B. Monell
At a mere 500 000 years old — a small fraction of the Pleiades open cluster’s age of 115 million years — Trumpler 14 is not only one of the most populous clusters within the Carina Nebula, but also the youngest. However, it is fast making up for lost time, forming stars at an incredible rate and putting on a stunning visual display.
This region of space houses one of the highest concentrations of massive, luminous stars in the entire Milky Way — a spectacular family of young, bright, white-blue stars. These stars are rapidly working their way through their vast supplies of hydrogen, and have only a few million years of life left before they meet a dramatic demise and explode as supernovae. In the meantime, despite their youth, these stars are making a huge impact on their environment. They are literally making waves!
As the stars fling out high-speed particles from their surfaces, strong winds surge out into space. These winds collide with the surrounding material, causing shock waves that heat the gas to millions of degrees and trigger intense bursts of X-rays. These strong stellar winds also carve out cavities in nearby clouds of gas and dust, and kickstart the formation of new stars.
The peculiar arc-shaped cloud visible at the very bottom of this image is suspected to be the result of such a wind. This feature is thought to be a bow shock created by the wind flowing from the nearby star Trumpler 14 MJ 218. Astronomers have observed this star to be moving through space at some 350 000 kilometres per hour, sculpting the surrounding clumps of gas and dust as it does so.
Astronomers estimate that around 2000 stars reside within Trumpler 14, ranging in size from less than one tenth to up to several tens of times the mass of the Sun. The most prominent star in Trumpler 14, and the brightest star in this image, is the supergiant HD 93129Aa . It is one of the most brilliant and hottest stars in our entire galaxy.
 HD 93129Aa is part of the binary star system HD 93129AaAb consisting of HD 93129Aa and HD 93129Ab. HD 93129Aa is an O-type star that is approximately two and a half million times brighter than the Sun, and has a mass 80 times greater. It forms a close binary with another massive star within the open cluster, meaning that the two orbit around a shared centre of mass. With a surface temperature of over 50 000 degrees, HD 93129Aa is one of the hottest O-type stars in the entire Milky Way.
The big space news of the day is the possibility of a big new planet in our solar system:
Caltech researchers have found evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer solar system. The object, which the researchers have nicknamed Planet Nine, has a mass about 10 times that of Earth and orbits about 20 times farther from the sun on average than does Neptune (which orbits the sun at an average distance of 2.8 billion miles). In fact, it would take this new planet between 10,000 and 20,000 years to make just one full orbit around the sun.The researchers, Konstantin Batygin and Mike Brown, discovered the planet’s existence through mathematical modeling and computer simulations but have not yet observed the object directly.
“This would be a real ninth planet,” says Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy. “There have only been two true planets discovered since ancient times, and this would be a third. It’s a pretty substantial chunk of our solar system that’s still out there to be found, which is pretty exciting.”Brown notes that the putative ninth planet—at 5,000 times the mass of Pluto—is sufficiently large that there should be no debate about whether it is a true planet. Unlike the class of smaller objects now known as dwarf planets, Planet Nine gravitationally dominates its neighborhood of the solar system. In fact, it dominates a region larger than any of the other known planets—a fact that Brown says makes it “the most planet-y of the planets in the whole solar system.”
Batygin and Brown describe their work in the current issue of the Astronomical Journal and show how Planet Nine helps explain a number of mysterious features of the field of icy objects and debris beyond Neptune known as the Kuiper Belt.
“Although we were initially quite skeptical that this planet could exist, as we continued to investigate its orbit and what it would mean for the outer solar system, we become increasingly convinced that it is out there,” says Batygin, an assistant professor of planetary science. “For the first time in over 150 years, there is solid evidence that the solar system’s planetary census is incomplete.”The road to the theoretical discovery was not straightforward. In 2014, a former postdoc of Brown’s, Chad Trujillo, and his colleague Scott Sheppard published a paper noting that 13 of the most distant objects in the Kuiper Belt are similar with respect to an obscure orbital feature. To explain that similarity, they suggested the possible presence of a small planet. Brown thought the planet solution was unlikely, but his interest was piqued.
He took the problem down the hall to Batygin, and the two started what became a year-and-a-half-long collaboration to investigate the distant objects. As an observer and a theorist, respectively, the researchers approached the work from very different perspectives—Brown as someone who looks at the sky and tries to anchor everything in the context of what can be seen, and Batygin as someone who puts himself within the context of dynamics, considering how things might work from a physics standpoint. Those differences allowed the researchers to challenge each other’s ideas and to consider new possibilities. “I would bring in some of these observational aspects; he would come back with arguments from theory, and we would push each other. I don’t think the discovery would have happened without that back and forth,” says Brown. ” It was perhaps the most fun year of working on a problem in the solar system that I’ve ever had.”
Fairly quickly Batygin and Brown realized that the six most distant objects from Trujillo and Shepherd’s original collection all follow elliptical orbits that point in the same direction in physical space. That is particularly surprising because the outermost points of their orbits move around the solar system, and they travel at different rates.
“It’s almost like having six hands on a clock all moving at different rates, and when you happen to look up, they’re all in exactly the same place,” says Brown. The odds of having that happen are something like 1 in 100, he says. But on top of that, the orbits of the six objects are also all tilted in the same way—pointing about 30 degrees downward in the same direction relative to the plane of the eight known planets. The probability of that happening is about 0.007 percent. “Basically it shouldn’t happen randomly,” Brown says. “So we thought something else must be shaping these orbits.”
The first possibility they investigated was that perhaps there are enough distant Kuiper Belt objects—some of which have not yet been discovered—to exert the gravity needed to keep that subpopulation clustered together. The researchers quickly ruled this out when it turned out that such a scenario would require the Kuiper Belt to have about 100 times the mass it has today.
That left them with the idea of a planet. Their first instinct was to run simulations involving a planet in a distant orbit that encircled the orbits of the six Kuiper Belt objects, acting like a giant lasso to wrangle them into their alignment. Batygin says that almost works but does not provide the observed eccentricities precisely. “Close, but no cigar,” he says.
Then, effectively by accident, Batygin and Brown noticed that if they ran their simulations with a massive planet in an anti-aligned orbit—an orbit in which the planet’s closest approach to the sun, or perihelion, is 180 degrees across from the perihelion of all the other objects and known planets—the distant Kuiper Belt objects in the simulation assumed the alignment that is actually observed.
“Your natural response is ‘This orbital geometry can’t be right. This can’t be stable over the long term because, after all, this would cause the planet and these objects to meet and eventually collide,'” says Batygin. But through a mechanism known as mean-motion resonance, the anti-aligned orbit of the ninth planet actually prevents the Kuiper Belt objects from colliding with it and keeps them aligned. As orbiting objects approach each other they exchange energy. So, for example, for every four orbits Planet Nine makes, a distant Kuiper Belt object might complete nine orbits. They never collide. Instead, like a parent maintaining the arc of a child on a swing with periodic pushes, Planet Nine nudges the orbits of distant Kuiper Belt objects such that their configuration with relation to the planet is preserved.
“Still, I was very skeptical,” says Batygin. “I had never seen anything like this in celestial mechanics.”
But little by little, as the researchers investigated additional features and consequences of the model, they became persuaded. “A good theory should not only explain things that you set out to explain. It should hopefully explain things that you didn’t set out to explain and make predictions that are testable,” says Batygin.
And indeed Planet Nine’s existence helps explain more than just the alignment of the distant Kuiper Belt objects. It also provides an explanation for the mysterious orbits that two of them trace. The first of those objects, dubbed Sedna, was discovered by Brown in 2003. Unlike standard-variety Kuiper Belt objects, which get gravitationally “kicked out” by Neptune and then return back to it, Sedna never gets very close to Neptune. A second object like Sedna, known as 2012 VP113, was announced by Trujillo and Shepherd in 2014. Batygin and Brown found that the presence of Planet Nine in its proposed orbit naturally produces Sedna-like objects by taking a standard Kuiper Belt object and slowly pulling it away into an orbit less connected to Neptune.
But the real kicker for the researchers was the fact that their simulations also predicted that there would be objects in the Kuiper Belt on orbits inclined perpendicularly to the plane of the planets. Batygin kept finding evidence for these in his simulations and took them to Brown. “Suddenly I realized there are objects like that,” recalls Brown. In the last three years, observers have identified four objects tracing orbits roughly along one perpendicular line from Neptune and one object along another. “We plotted up the positions of those objects and their orbits, and they matched the simulations exactly,” says Brown. “When we found that, my jaw sort of hit the floor.”
“When the simulation aligned the distant Kuiper Belt objects and created objects like Sedna, we thought this is kind of awesome—you kill two birds with one stone,” says Batygin. “But with the existence of the planet also explaining these perpendicular orbits, not only do you kill two birds, you also take down a bird that you didn’t realize was sitting in a nearby tree.”
Where did Planet Nine come from and how did it end up in the outer solar system? Scientists have long believed that the early solar system began with four planetary cores that went on to grab all of the gas around them, forming the four gas planets—Jupiter, Saturn, Uranus, and Neptune. Over time, collisions and ejections shaped them and moved them out to their present locations. “But there is no reason that there could not have been five cores, rather than four,” says Brown. Planet Nine could represent that fifth core, and if it got too close to Jupiter or Saturn, it could have been ejected into its distant, eccentric orbit.
Batygin and Brown continue to refine their simulations and learn more about the planet’s orbit and its influence on the distant solar system. Meanwhile, Brown and other colleagues have begun searching the skies for Planet Nine. Only the planet’s rough orbit is known, not the precise location of the planet on that elliptical path. If the planet happens to be close to its perihelion, Brown says, astronomers should be able to spot it in images captured by previous surveys. If it is in the most distant part of its orbit, the world’s largest telescopes—such as the twin 10-meter telescopes at the W. M. Keck Observatory and the Subaru Telescope, all on Mauna Kea in Hawaii—will be needed to see it. If, however, Planet Nine is now located anywhere in between, many telescopes have a shot at finding it.
“I would love to find it,” says Brown. “But I’d also be perfectly happy if someone else found it. That is why we’re publishing this paper. We hope that other people are going to get inspired and start searching.”
In terms of understanding more about the solar system’s context in the rest of the universe, Batygin says that in a couple of ways, this ninth planet that seems like such an oddball to us would actually make our solar system more similar to the other planetary systems that astronomers are finding around other stars. First, most of the planets around other sunlike stars have no single orbital range—that is, some orbit extremely close to their host stars while others follow exceptionally distant orbits. Second, the most common planets around other stars range between 1 and 10 Earth-masses.
“One of the most startling discoveries about other planetary systems has been that the most common type of planet out there has a mass between that of Earth and that of Neptune,” says Batygin. “Until now, we’ve thought that the solar system was lacking in this most common type of planet. Maybe we’re more normal after all.”
Brown, well known for the significant role he played in the demotion of Pluto from a planet to a dwarf planet adds, “All those people who are mad that Pluto is no longer a planet can be thrilled to know that there is a real planet out there still to be found,” he says. “Now we can go and find this planet and make the solar system have nine planets once again.”
The paper is titled “Evidence for a Distant Giant Planet in the Solar System.”