Special Guests:
This week, we are excited to welcome Skylias, aka “”Sky”” to the Weekly Space Hangout. Sky is a science communicator on Twitch.tv. She discovered her passion for live streaming science, mainly astronomy/physics on Twitch.tv, while working towards her own science degree. Sky graduated magna cum laude from Regis University with a B.S. in Computer Science. While not in front of the camera or working on future live stream content, Sky enjoys stargazing, learning more about science and history, and spending time with her 5 year old daughter who is known as “”MiniSky.””
Be sure to check out Sky on Twitch here: https://www.twitch.tv/skylias
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Artist's concept of the hypothetical "Planet Nine." Could it have moons? Credit: NASA/JPL-Caltech/Robert Hurt
In the past few decades, thanks to improvements in ground-based and space-based observatories, astronomers have discovered thousands of planets orbiting neighboring and distant stars (aka. extrasolar planets). Strangely enough, it is these same improvements, and during the same time period, that enabled the discovery of more astronomical bodies within the Solar System.
These include the “minor planets” of Eris, Sedna, Haumea, Makemake, and others, but also the hypothesized planetary-mass objects collectively known as Planet 9 (or Planet X). In a new study led by Northern Arizona University and the Lowell Observatory, a team of researchers hypothesize that the Large Synoptic Survey Telescope (LSST) – a next-generation telescope that will go online in 2022 – has a good chance of finding this mysterious planet.
Their study, titled “On the detectability of Planet X with LSST“, recently appeared online. The study was led by David E. Trilling, an astrophysicist from the Northern Arizona University and the Lowell Observatory, and included Eric C. Bellm from the University of Washington and Renu Malhotra of the Lunar and Planetary Laboratory at The University of Arizona.
Artist’s impression of the Large Synoptic Survey Telescope (LSST). Credit: lsst.org
Located on the Cerro Pachón ridge in north-central Chile, the 8.4-meter LSST will conduct a 10-year survey of the sky that will deliver 200 petabytes worth of images and data that will address some of the most pressing questions about the structure and evolution of the Universe and the objects in it. In addition to surveying the early Universe in order to understand the nature of dark matter and dark energy, it will also conduct surveys of the remote areas of the Solar System.
Planet 9/X is one such object. In recent years, the existence of two planetary-mass bodies have been hypothesized to explain the orbital distribution of distant Kuiper Belt Objects. While neither planet is thought to be exceptionally faint, the sky locations of these planets are poorly constrained – making them difficult to pinpoint. As such, a wide area survey is needed to detect these possible planets.
In 2022, the LSST will carry out an unbiased, large and deep survey of the southern sky, which makes it an important tool when it comes to the search of these hypothesized planets. As they state in their study:
“The possibility of undiscovered planets in the solar system has long fascinated astronomers and the public alike. Recent studies of the orbital properties of very distant Kuiper belt objects (KBOs) have identified several anomalies that may be due to the gravitational influence of one or more undiscovered planetary mass objects orbiting the Sun at distances comparable to the distant KBOs.
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” (aka. “Planet X”). Credit: Caltech/nagualdesign
These studies include Trujillo & Sheppard’s 2014 study where they noticed similarities in the orbits of distant Trans-Neptunian Objects (TNOs) and postulated that a massive object was likely influencing them. This was followed by a 2016 study by Sheppard & Trujillo where they suggested that the high perihelion objects Sedna and 2012 VP113 were being influence by an unknown massive planet.
This was followed in 2016 by Konstantin Batygin and Michael E. Brown of Caltech suggesting that an undiscovered planet was the culprit. Finally, Malhotra et al. (2016) noted that the most distant KBOs have near-integer period ratios, which was suggestive of a dynamical resonance with a massive object in the outer Solar System. Between these studies, various mass and distance estimates were formed that became the basis of the search for this planet.
Overall, these estimates indicated that Planet 9/X was a super-Earth with anywhere between 5 to 20 Earth masses, and orbited the Sun at a distance of between 150 – 600 AU. Concurrently, these studies have also attempted to narrow down where this Super-Earth’s orbit will take it throughout the outer Solar System, as evidenced by the perturbations it has on KBOs.
Unfortunately, the predicted locations and brightness of the object are not yet sufficiently constrained for astronomers to simply look in the right place at the right time and pick it out. In this respect, a large area sky survey must be carried out using moderately large telescopes with a very wide field of view. As Dr. Trilling told Universe Today via email:
“The predicted Planet X candidates are not particularly faint, but the possible locations on the sky are not very well constrained at all. Therefore, what you really need to find Planet X is a medium-depth telescope that covers a huge amount of sky. This is exactly LSST. LSST’s sensitivity will be sufficient to find Planet X in almost all its (their) predicted configurations, and LSST will cover around half of the known sky to this depth. Furthermore, the cadence is well-matched to finding moving objects, and the data processing systems are very advanced. If you were going to design a tool to find Planet X, LSST is what you would design.”
The orbits of several KBOs provide indications about the possible existence of Planet 9. Credit: Caltech/R. Hurt (IPAC)
However, the team also acknowledges that within certain parameters, Planet 9/X may not be detectable by the LSST. For example, it is possible that that there is a very narrow slice of predicted Planet 9/X parameters where it might be slightly too faint to be easily detected in LSST data. In addition, there is also a small possibility that irregularities in the Planet 9/X cadence might lead to it being missed.
There is the even the unlikely ways in which Planet 9/X could go undetected in LSST data, which would come down to a simple case of bad luck. However, as Dr. Trilling indicated, the team is prepared for these possibilities and is hopeful they will find Planet 9/X, assuming there’s anything to find:
“The more likely conclusion if planet X is not detected in LSST data is that planet X doesn’t exist – or at least not the kind of planet X that has been predicted. In this case, we’ve got to work harder to understand how the Universe created this pattern of orbits in the outer Solar System that I described above. This is a really fun part of science: make a prediction and test it, and find that the result is rarely what is predicted. So now we’ve got to work harder to understand the universe. Hopefully this new understanding makes new predictions that we then can test, and we repeat the cycle.”
The existence of Planet 9/X has been one of the more burning questions for astronomers in recent years. If its existence can be confirmed, astronomers may finally have a complete picture of the Solar System and its dynamics. If it’s existence can be ruled out, this will raise a whole new series of questions about what is going on in the Outer Solar System!
Close-up of star near a supermassive black hole (artist’s impression). Credit: ESA/Hubble, ESO, M. Kornmesser
At the center of our galaxy resides a Supermassive Black Hole (SMBH) known as Sagittarius A. Based on ongoing observations, astronomers have determined that this SMBH measures 44 million km (27.34 million mi) in diameter and has an estimated mass of 4.31 million Solar Masses. On occasion, a star will wander too close to Sag A and be torn apart in a violent process known as a tidal disruption event (TDE).
These events cause the release of bright flares of radiation, which let astronomers know that a star has been consumed. Unfortunately, for decades, astronomers have been unable to distinguish these events from other galactic phenomena. But thanks to a new study from by an international team of astrophysicists, astronomers now have a unified model that explains recent observations of these extreme events.
Illustration of the supermassive black hole at the center of the Milky Way. Credit: NRAO/AUI/NSF
As Enrico Ramirez-Ruiz – the professor and chair of astronomy and astrophysics at UC Santa Cruz, the Niels Bohr Professor at the University of Copenhagen, and a co-author on the paper – explained in a UCSC press release:
“Only in the last decade or so have we been able to distinguish TDEs from other galactic phenomena, and the new model will provide us with the basic framework for understanding these rare events.”
In most galaxies, SMBHs do not actively consume any material and therefore do not emit any light, which distinguishes them from galaxies that have Active Galactic Nuclei (AGNs). Tidal disruption events are therefore rare, occurring only once about every 10,000 years in a typical galaxy. However, when a star does get torn apart, it results in the release of an intense amount of radiation. As Dr. Dai explained:
“It is interesting to see how materials get their way into the black hole under such extreme conditions. As the black hole is eating the stellar gas, a vast amount of radiation is emitted. The radiation is what we can observe, and using it we can understand the physics and calculate the black hole properties. This makes it extremely interesting to go hunting for tidal disruption events.”
Illustration of emissions from a tidal disruption event shows in cross section what happens when the material from a disrupted star is devoured by a black hole. Credit: Jane Lixin Dai
In the past few years, a few dozen candidates for tidal disruption events (TDEs) have been detected using wide-field optical and UV transient surveys as well as X-ray telescopes. While the physics are expected to be the same for all TDEs, astronomers have noted that a few distinct classes of TDEs appear to exist. While some emit mostly x-rays, others emit mostly visible and ultraviolet light.
As a result, theorists have struggled to understand the diverse properties observed and create a coherent model that can explain them all. For the sake of their model, Dr. Dai and her colleagues combined elements from general relativity, magnetic fields, radiation, and gas hydrodynamics. The team also relied on state-of-the-art computational tools and some recently-acquired large computer clusters funded by the Villum Foundation for Jens Hjorth (head of DARK Cosmology Center), the U.S. National Science Foundation and NASA.
Using the model that resulted, the team concluded that it is the viewing angle of the observer that accounts for the differences in observation. Essentially, different galaxies are oriented randomly with respect to observers on Earth, who see different aspects of TDEs depending on their orientation. As Ramirez-Ruiz explained:
“It is like there is a veil that covers part of a beast. From some angles we see an exposed beast, but from other angles we see a covered beast. The beast is the same, but our perceptions are different.”
Artist’s impression of the Large Synoptic Survey Telescope. Credit: lsst.org
In the coming years, a number of planned survey projects are expected to provide much more data on TDEs, which will help expand the field of research into this phenomena. These include the Young Supernova Experiment (YSE) transient survey, which will be led by the DARK Cosmology Center at the Niels Bohr Institute and UC Santa Cruz, and the Large Synoptic Survey Telescopes (LSST) being built in Chile.
According to Dr. Dai, this new model shows what astronomers can expect to see when viewing TDEs from different angles and will allow them to fit different events into a coherent framework. “We will observe hundreds to thousands of tidal disruption events in a few years,” she said. “This will give us a lot of ‘laboratories’ to test our model and use it to understand more about black holes.”
This improved understanding of how black holes occasionally consume stars will also provide additional tests for general relativity, gravitational wave research, and help astronomers to learn more about the evolution of galaxies.
Saturn, Mars and Jupiter all beckon this summer. Image credit and copyright: Sharin Ahmad (@shahgazer)
Saturn, Mars and Jupiter all beckon this summer. Image credit and copyright: Sharin Ahmad (@shahgazer).
We’re in the midst of a parade of planets crossing the evening sky. Jupiter reached opposition on May 9th, and sits high to the east at dusk. Mars heads towards a fine opposition on July 27th, nearly as favorable as the historic opposition of 2003. And Venus rules the dusk sky in the west after the setting Sun for most of 2018.
June is Saturn’s turn, as the planet reaches opposition this year on June 27th, rising opposite to the setting Sun at dusk.
In classical times, right up until just over two short centuries ago, Saturn represented the very outer limit of the solar system, the border lands where the realm of the planets came to an end. Sir William Herschel extended this view, when he spied Uranus—the first planet discovered in the telescopic era—slowly moving through the constellation Gemini just across the border of Taurus the Bull using a 7-foot reflector (in the olden days, telescopes specs were often quoted referring to their focal length versus aperture) while observing from his backyard garden in Bath, England on the night of March 13th, 1781.
Looking east tonight at sunset… note Vesta to the upper left. Credit: Stellarium.
Orbiting the Sun once every 29.5 years, Saturn is the slowest moving of the naked eye planets, fitting for a planet named after Father Time. Saturn slowly loops from one astronomical constellation along the zodiac to the next eastward, moving through one about every two years.
The path of Saturn through 2018. Image credit: Starry Night Education software.
2018 sees Saturn in the constellation Sagittarius the Archer, just above the ‘lid’ of the Teapot asterism, favoring the southern hemisphere for this apparition. Saturn won’t cross the celestial equator northward again until 2026. Not that that should discourage northern hemisphere viewers from going after this most glorious of planets. A low southerly declination also means that Saturn is also up in the evening in the summertime up north, a conducive time for observing. Taking 29-30 years to complete one lap around the ecliptic as seen from our Earthly vantage point, Saturn also makes a great timekeeper with respect to personal life milestones… where were you back in 1989, when Saturn occupied the same spot along the ecliptic?
Saturn also shows the least variation of all the planets in terms of brightness and size, owing to its immense distance 9.5 AU from the Sun, and consequently 8.5 to 10.5 AU from the Earth. Saturn actually just passed its most distant aphelion since 1959 on April 17th, 2018 at 10.066 AU from the Sun.
Saturn’s in 2018 Dates with Destiny
Saturn sits just 1.6 degrees south of the waning gibbous Moon tonight. The Moon will lap it again one lunation later on June 28th. Note that the brightest of the asteroids, +5.7 magnitude 4 Vesta is nearby in northern Sagittarius, also reaching opposition on June 19th. Can you spy Vesta with the naked eye from a dark sky site? 4 Vesta passes just 4 degrees from Saturn on September 23rd, and both flirt with the galactic plane and some famous deep sky targets, including the Trifid and Lagoon Nebulae.
Saturn reaches quadrature 90 degrees east of the Sun on September 25th, then ends its evening apparition when it reaches solar conjunction on New Year’s Day, 2019.
Saturn is well clear of the Moon’s path for most of this year, but stick around: starting on December 9th, 2018, the slow-moving planet will make a great target for the Moon, which will begin occulting it for every lunation through the end of 2019.
It’s ironic: Saturn mostly hides its beauty to unaided eye. Presenting a slight saffron color in appearance, it never strays much from magnitude -0.2 to +1.4 in brightness. One naked eye observation to watch for is a sudden spurt in brightness known as the opposition surge or Seeliger Effect. This is a retro reflector type effect, caused by all those tiny iceball moonlets in the rings reaching 100% illumination at once. Think of how the Full Moon is actually 3 to 4 times brighter than the 50% illuminated Quarter Moon… all those little peaks, ridges and crater rims no longer casting shadows do indeed add up.
Saturn in all its glory (note the moons Enceladus and Tethys, too!). Image credit and copyright: Efrain Morales.
And this effect is more prominent in recent years for another reason: Saturn’s rings passed maximum tilt (26.7 degrees) with respect to our line of sight just last year, and are still relatively wide open in 2018. They’ll start slimming down again over the next few oppositions, reaching edge-on again in 2028.
Even using a pair of 7×50 hunting binoculars on Saturn, you can tell that something is amiss. You’re getting the same view that Galileo had through his spyglass, the pinnacle of early 17th century technology. He could tell that something about the planet was awry, and drew sketches showing an oblong world with coffee cup handles on the side. Crank up the magnification using even a small 60 mm refractor, and the rings easily jump into view. This is what makes Saturn a star party staple, an eye candy feast capable of drawing the aim of all the telescopes down the row.
If seeing and atmospheric conditions allow, crank up the magnification up to 150x or higher, and the dark groove of the Cassini division snaps into view. Can you see the shadow of the disk of Saturn, cast back onto the plane of the rings? The shadow of the planet hides behind it near opposition, then becomes most prominent towards quadrature, when we get to peek around its edge. Can you spy the limb of the planet itself, through the Cassini Gap?
Though the disk of Saturn is often featureless, tiny swirls of white storms do occasionally pop up. Astrophotographer Damian Peach noted just one such short-lived storm on the ringed planet this past April 2018.
Saturn’s retinue of moons are also interesting to follow in there own right. The first one you’ll note is +8.5 magnitude smog-shrouded Titan. Larger in diameter than Mercury, Titan would easily be a planet in its own right, were it liberated from its primary’s domain.
Though Saturn has 62 known moons, only six in addition to Titan are in range of a modest backyard telescope: Enceladus, Rhea, Dione, Mimas, Tethys and Iapetus. Two-faced Iapetus is especially interesting to follow, as it varies two full magnitudes in brightness during its 79 day orbit. Arthur C. Clarke originally placed the final monolith in 2001: A Space Odyssey on this moon, its artificial coating a beacon to astronomers. Today, we know from flybys carried out by NASA’s Cassini spacecraft that the leading hemisphere of Iapetus is coated with dark in-falling material, originating from the dark Phoebe ring around Saturn.
Owners of large light bucket telescopes may also want to try from two fainter +15th magnitude moons: Hyperion and Phoebe.
Fun fact: Saturn’s moons can also cast shadows back on the planet itself, much like the Galilean moons do on Jupiter… the catch, however, is that these events only occur around equinox season in the years around when Saturn’s rings are edge-on. This next occurs starting in 2026.
Cassini finished up its thrilling 20 year mission just last year, with a dramatic plunge into Saturn itself. It will be a while before we return again, perhaps in the next decade if NASA selects a nuclear-powered helicopter to explore Titan. Until then, be sure to explore Saturn this summer, from your Earthbound backyard.
Virgin Galactic’s VSS Unity conducted her second powered test flight on Tuesday, May 29th. With six flights under their belts, the VG crews are planning for more in 2024. Credit: Virgin Galactic
When it comes to the dream of commercial space exploration and space tourism, a few names really stand out. In addition to Elon Musk and Jeff Bezos, you have Richard Branson – the founder and CEO of the Virgin Group. For years, Branson has sought to make space tourism a reality through Virgin Galactic, which would take passengers into suborbit using his SpaceShipTwo class of rocket planes.
Unfortunately, Virgin Galactic suffered a number of setbacks in recent years, at the same time that competitors like SpaceX and Blue Origin emerged as competitors. However, the VSS Unity (part of the Virgin Galactic fleet) recently conducted its second powered test flight from the Mojave Air and Space Port on Tuesday, May 29th. While this test is years behind schedule, it marks a significant step towards Branson’s realization of flying customers to space.
This was the second time that the VSS Unity flew since 2014, when the VSS Enterprise suffered a terrible crash while attempting to land, killing one pilot and injuring the other. The first propulsive test took place two months ago after several additional tests were performed on the craft. And with that last success, Virgin Galactic moved ahead with its second powered test earlier this week.
The focus of the latest test flight was to learn more about how the spaceship handles at supersonic speeds. It was also intended to test the control system’s performance when the vehicle was closer to its ultimate commercial configuration. As the company stated, “This involved shifting the vehicle’s center of gravity rearward via the addition of passenger seats and related equipment.”
This statement is a possible indication that the test program is reaching the final stretch before Virgin Galactic allows passengers on the vehicle. However, the company will need to conduct a full-duration flight (which will include a full-duration burn of its rocket motor) before that can happen. This latest test involved only a partial rocket burn, but nevertheless demonstrated the spacecraft’s capabilities at supersonic speed.
The company live-tweeted the entire event, which began at 8:34 AM with the VSS Unity and its carrier mothership (VMS Eve) taxing out to the runway for final checks. For this flight, the pilots were Dave Mackay and Mark “Forger” Stucky while CJ Sturckow and Nicola Pecile piloted of the carrier aircraft. At 8:42 AM (PDT), both craft lifted off, with the company tweeting, “We have take-off. VMS Eve & VSS Unity have taken to the skies and have begun their climb.”
By 9:43 AM, the company announced that the VSS Unity had detached from the VMS Eve and was “flying free”. What followed was a series of live-tweets that indicated the ignition of the VSS Unity’s rocket motor, the shutting down of the motor, and the raising of the tail fins to the “feathered” re-entry position. By 9:55 AM, the company announced a smooth landing for the VSS Unity, signaling the end of the test.
Branson, who was at the Mojave Air and Space Port for the test, released the following statement shortly thereafter:
“It was great to see our beautiful spaceship back in the air and to share the moment with the talented team who are taking us, step by step, to space. Seeing Unity soar upwards at supersonic speeds is inspiring and absolutely breathtaking. We are getting ever closer to realizing our goals. Congratulations to the whole team!”
Branson was also at the center to take in a tour of the facilities of The Spaceship Company (TSC), a sister company of Virgin Galactic that is responsible for developing Virgin Galactic’s future fleet. While there, Branson viewed the next two spaceships that TSC is currently manufacturing, as well as the production facilities for TSC’s spaceship rocket motors.
With the latest test flight complete, the company’s teams will be reviewing the data from this flight and making preparations for the next flight. No indication has been given as to when that will be, or if this test flight will include a full-duration burn of the motor. However, Branson was very happy with the test results, stating:
“Today we saw VSS Unity in her natural environment, flying fast under rocket power and with a nose pointing firmly towards the black sky of space. The pathway that Unity is forging is one that many thousands of us will take over time, and will help share a perspective that is crucial to solving some of humanity’s toughest challenges on planet Earth.”
Artists’ impression of Moon Base Alpha, SpaceX’s envisioned lunar outpost supplied with the BFR. Credit: SpaceX
Meanwhile, Bezos continues to pursue his plans for sending passengers into orbit using his fleet of New Shepard rockets. And of course, Musk continues to pursue the idea of sending tourists to the Moon and Mars using his Big Falcon Rocket (BFR). And with many other private aerospace ventures looking to provide trips into orbit or to the surface of the Moon, there is sure to be no shortage of options for going into space in the near future!
And be sure to check out this video of the VSS Unity’s second test flight, courtesy of Virgin Galactic:
NASA Photographer Bill Ingalls's camera after it was caught in brushfire caused by the launch of the NASA/German GRACE-FO from Vandenberg Air Force Base on May 22, 2018. Credits: NASA/Bill Ingalls
NASA photographers have always understood that taking pictures of space launches is a risky business. No one is more familiar with this than Bill Ingalls, a NASA photographer who has taking pictures for the agency for the past 30 years. Both within the agency and without, his creativity and efforts are well known, as his ability to always know exactly where to set up his cameras to get the perfect shots.
Which naturally begs the question, what happened to the camera featured in the image above? This photograph, which shows one of Ingalls remote cameras thoroughly-melted, has been making the rounds on social media of late. As the accompanying gif (seen below) shows, the camera was not far from the launch pad and was then quickly consumed by the resulting fire.
As Ingalls explained in a recent NASA press release, the destruction of the camera was the result of an unexpected brush fire that was triggered when flames from the launching rocket set some of the nearby grass on fire.
“I had six remotes, two outside the launch pad safety perimeter and four inside,” he said. “Unfortunately, the launch started a grass fire that toasted one of the cameras outside the perimeter.”
The event he was photographing was the launch of the NASA/German Gravity Recovery and Climate Experiment Follow-on (GRACE-FO) satellite, which took place at Vandenberg Air Force Base on May 22nd, 2018. As part of a partnership between NASA and the German Research Center for Geosciences (GFZ), this satellite is the successor to the original GRACE mission, which began orbiting Earth on March 17th, 2002.
Unfortunately, the launch triggered a brush fire which engulfed the camera and cause its body to melt. Firefighters reported to the scene to put out the fire, who then met Ingalls where he returned to the site. Luckily for Ingalls, and the viewing public, he was able to force open the body and retrieve the memory card, which had not been damaged. As a result, the footage of the fire as it approached the camera was caught.
NASA Photographer Bill Ingalls’s remote camera setup before the NASA/German GRACE-FO launch from Vandenberg Air Force Base on May 22, 2018. Credits: NASA/Bill Ingalls
Oddly enough, this camera was the one posted furthest from the launch pad, about 400 meters (a quarter of a mile) away. The four other cameras that were set up inside the perimeter were undamaged, as was the other remote camera. But before anyone starts thinking that this remote was the unfortunate one, the “toasty” camera, as Ingalls calls it, is likely to put on display at NASA Headquarters in Washington, DC.
In the meantime, Ingalls will be traveling to Kazakhstan to photograph the June 3rd landing of the International Space Station’s Expedition 55 crew. He anticipates that that assignment, unlike this last one, will have no surprises!
Artist’s impression of the pulsar PSR B1957+20 (seen in the background) through the cloud of gas enveloping its brown dwarf star companion. Credit: Dr. Mark A. Garlick; Dunlap Institute for Astronomy & Astrophysics, University of Toronto
Astronomy can be a tricky business, owing to the sheer distances involved. Luckily, astronomers have developed a number of tools and strategies over the years that help them to study distant objects in greater detail. In addition to ground-based and space-based telescopes, there’s also the technique known as gravitational lensing, where the gravity of an intervening object is used to magnify light coming from a more distant object.
Recently, a team of Canadian astronomers used this technique to observe an eclipsing binary millisecond pulsar located about 6500 light years away. According to a study produced by the team, they observed two intense regions of radiation around one star (a brown dwarf) to conduct observations of the other star (a pulsar) – which happened to be the highest resolution observations in astronomical history.
The study, titled “Pulsar emission amplified and resolved by plasma lensing in an eclipsing binary“, recently appeared in the journal Nature. The study was led by Robert Main, a PhD astronomy student at the University of Toronto’s Dunlap Institute for Astronomy & Astrophysics, and included members from the Canadian Institute for Theoretical Astrophysics, the Perimeter Institute for Theoretical Physics, and the Canadian Institute for Advanced Research.
The system they observed is known as the “Black Widow Pulsar”, a binary system that consists of a brown dwarf and a millisecond pulsar orbiting closely to each other. Because of their close proximity to one another, scientists have determined that the pulsar is actively siphoning material from its brown dwarf companion and will eventually consume it. Discovered in 1988, the name “Black Widow” has since come to be applied to other similar binaries.
The observations made by the Canadian team were made possible thanks to the rare geometry and characteristics of the binary – specifically, the “wake” or comet-like tail of gas that extends from the brown dwarf to the pulsar. As Robert Main, the lead author of the paper, explained in a Dunlap Institute press release:
“The gas is acting like a magnifying glass right in front of the pulsar. We are essentially looking at the pulsar through a naturally occurring magnifier which periodically allows us to see the two regions separately.”
Like all pulsars, the “Black Widow” is a rapidly rotating neutron star that spins at a rate of over 600 times a second. As it spins, it emits beams of radiation from its two polar hotspots, which have a strobing effect when observed from a distance. The brown dwarf, meanwhile, is about one third the diameter of the Sun, is located roughly two million km from the pulsar and orbits it once every 9 hours.
Image of the pulsar surrounded by its bow shock. White rays indicate particles of matter and antimatter being spewed from the star. Its companion star is too close to the pulsar to be visible at this scale. Credit: NASA/CXC/M.Weiss
Because they are so close together, the brown dwarf is tidally-locked to the pulsar and is blasted by strong radiation. This intense radiation heats one side of the relatively cool brown dwarf to temperatures of about 6000 °C (10,832 °F), the same temperature as our Sun. Because of the radiation and gases passing between them, the emissions coming from the pulsar interfere with each other, which makes them difficult to study.
However, astronomers have long understood that these same regions could be used as “interstellar lenses” that could localize pulsar emission regions, thus allowing for their study. In the past, astronomers have only been able to resolve emission components marginally. But thanks to the efforts of Main and his colleagues, they were able observing two intense radiation flares located 20 kilometers apart.
In addition to being an unprecedentedly high-resolution observation, the results of this study could provide insight into the nature of the mysterious phenomena known as Fast Radio Bursts (FRBs). As Main explained:
“Many observed properties of FRBs could be explained if they are being amplified by plasma lenses. The properties of the amplified pulses we detected in our study show a remarkable similarity to the bursts from the repeating FRB, suggesting that the repeating FRB may be lensed by plasma in its host galaxy.”
It is an exciting time for astronomers, where improved instruments and methods are not only allowing for more accurate observations, but also providing data that could resolve long-standing mysteries. It seems that every few days, fascinating new discoveries are being made!
NASA's New Horizons spacecraft captured this image of Sputnik Planitia — a glacial expanse rich in nitrogen, carbon monoxide and methane ices — that forms the left lobe of a heart-shaped feature on Pluto’s surface. SwRI scientists studied the dwarf planet’s nitrogen and carbon monoxide composition to develop a new theory for its formation. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Pluto has been the focus of a lot of attention for more than a decade now. This began shortly after the discovery of Eris in the Kuiper Belt, one of many Kuiper Belt Objects (KBOs) that led to the “Great Planetary Debate” and the 2006 IAU Resolution. Interest in Pluto also increased considerably thanks to the New Horizons mission, which conducted the first flyby of this “dwarf planet” in July of 2015.
The data this mission provided on Pluto is still proving to be a treasure trove for astronomers, allowing for new discoveries about Pluto’s surface, composition, atmosphere, and even formation. For instance, a new study produced by researchers from the Southwest Research Institute (and supported by NASA Rosetta funding) indicates that Pluto may have formed from a billion comets crashing together.
The first Kuiper Belt is home to more than 100,000 asteroids and comets there over 62 miles (100 km) across. Credit: JHUAPL
The origin of Pluto is something that astronomers have puzzled over for some time. An early hypothesis was that it was an escaped moon of Neptune that had been knocked out of orbit by Neptune’s current largest moon, Triton. However, this theory was disproven after dynamical studies showed that Pluto never approaches Neptune in its orbit. With the discovery of the Kuiper Belt in 1992, the true of origin of Pluto began to become clear.
Essentially, while Pluto is the largest object in the Kuiper Belt, it is similar in orbit and composition to the icy objects that surround it. On occasion, some of these objects are kicked out of the Kuiper Belt and become long-period comets in the Inner Solar System. To determine if Pluto formed from billions of KBOs, Dr. Glein and Dr. Waite Jr. examined data from the New Horizons mission on the nitrogen-rich ice in Sputnik Planitia.
This large glacier forms the left lobe of the bright Tombaugh Regio feature on Pluto’s surface (aka. Pluto’s “Heart”). They then compared this to data obtained by the NASA/ESA Rosetta mission, which studied the comet 67P/Churyumov–Gerasimenko (67P) between 2014 and 2016. As Dr. Glein explained:
“We’ve developed what we call ‘the giant comet’ cosmochemical model of Pluto formation. We found an intriguing consistency between the estimated amount of nitrogen inside the glacier and the amount that would be expected if Pluto was formed by the agglomeration of roughly a billion comets or other Kuiper Belt objects similar in chemical composition to 67P, the comet explored by Rosetta.”
New Horizon’s July 2015 flyby of Pluto captured this iconic image of the heart-shaped region called Tombaugh Regio. Credit: NASA/JHUAPL/SwRI
This research also comes up against a competing theory, known as the “solar model”. In this scenario, Pluto formed from the very cold ices that were part of the protoplanetary disk, and would therefore have a chemical composition that more closely matches that of the Sun. In order to determine which was more likely, scientists needed to understand not only how much nitrogen is present at Pluto now (in its atmosphere and glaciers), but how much could have leaked out into space over the course of eons.
They then needed to come up with an explanation for the current proportion of carbon monoxide to nitrogen. Ultimately, the low abundance of carbon monoxide at Pluto could only be explained by burial in surface ices or destruction from liquid water. In the end, Dr. Glein and Dr. Waite Jr.’s research suggests that Pluto’s initial chemical makeup, which was created by comets, was modified by liquid water, possibly in the form of a subsurface ocean.
“This research builds upon the fantastic successes of the New Horizons and Rosetta missions to expand our understanding of the origin and evolution of Pluto,” said Dr. Glein. “Using chemistry as a detective’s tool, we are able to trace certain features we see on Pluto today to formation processes from long ago. This leads to a new appreciation of the richness of Pluto’s ‘life story,’ which we are only starting to grasp.”
While the research certainly offers an interesting explanation for how Pluto formed, the solar model still satisfies some criteria. In the end, more research will be needed before scientists can conclude how Pluto formed. And if data from the New Horizons or Rosetta missions should prove insufficient, perhaps another to New Frontiers mission to Pluto will solve the mystery!
This is a proposed LEGO set designed by Matthew Nolan and Valerie Roche (co-designer of the Saturn V set), consisting of three separate modules:
Block 5 Variant Falcon 9
For starters, you’ll get a Block 5 variant of the SpaceX Falcon 9 rocket, with its 9 Merlin engines, black interstage and titanium gridfins. The legs actually move up and down and lock in place for that rapid landing and easy reusablity. It also comes with a detachable upper stage with a variety of cargos. You can put a communications satellite into the detachable fairing, or a Dragon 2 capsule that’s ready to re-enter the Earth’s atmosphere with its heat shield. 371 bricks
Falcon 9 Block 5. Credit Matthew Nolan and Valerie RocheDragon 2 Capsule. Credit Matthew Nolan and Valerie Roche
Falcon Heavy
Then there’s a completely separate Falcon Heavy with its three detachable cores, each of which has its own landing legs. It has a detachable second stage with its Merlin Vacuum Engines and fuel tanks. At the top there’s a payload fairing, and inside that – this is the best part – there’s a tiny Tesla Roadster as a payload, so you can fly your car to space, just like Elon Musk. 453 bricks
Falcon HeavyTesla Roadster and Starman. Credit Matthew Nolan and Valerie Roche
Transporter/Erector/Launcher
And last but not least, the set comes with a SpaceX Transporter/Erector/Launcher that can hold and display either the Falcon 9 or the Falcon Heavy. You can clamp in either rocket and then raise or lower it, ready for launch. 759 bricks
Falcon Heavy on the Transporter. Credit Matthew Nolan and Valerie Roche
If LEGO does decide to build this awesome set, it’ll consist of 1,583 pieces, and measure 64 cm high when fully constructed at 1:110 scale.
Now, I know you’re wondering where you can buy one of these, but you can’t. Instead, you’ve got to help convince LEGO that this is a set that they should consider putting into production at LEGO Ideas. At the time that I’m writing this article, they’ve gotten 3440 supporters to join the campaign. Because of all the support, LEGO has extended their campaign twice, and now they’ve got 589 days left to reach the 10,000 supporters.
