Aquarius the "Water Bearer" is a large but faint constellation in the Southern sky. Credit: Stellarium
Welcome back to Constellation Friday! Today, we will be dealing with one of the best-known constellations, that “watery” asterism and section of the sky known as Aquarius. Cue the soundtrack from Hair!
In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of all the-then known constellations. This work (known as the Almagest) would remain the definitive guide to astronomy and astrology for over a thousand years. Among the 48 constellations listed in this book was Aquarius, a constellation of the zodiac that stretches from the celestial equator to the southern hemisphere.
An artist's illustration of the MOM orbiter at Mars. Image: By Nesnad - Own work, GFDL, https://commons.wikimedia.org/w/index.php?curid=29435816
Science—like literature and the arts—helps nations cooperate together, even when they’re in conflict politically. The USA and Russia are in conflict over the Ukraine and Syria, yet both nations still cooperate when it comes to the International Space Station. With that in mind, it’s great to see other nations—in this case India—taking on a greater role in space exploration and sharing their scientific results.
India’s Mars Orbiter Mission (MOM) probe has been in orbit around Mars since September 2014, after being launched in November 2013. Though the Indian Space Research Organization (ISRO) has released plenty of pictures of the surface of Mars, they haven’t released any scientific data. Until now.
A beautiful full-disc image of Mars captured by MOM. Image: ISRO/MOM.
In September 2015, MOM’s orbit was adjusted to bring it to within 260 km of Mars’ surface, significantly closer to the surface than the usual 400 km altitude. This manoeuver allowed one of MOM’s six instruments, the Mars Exospheric Neutral Composition Analyzer (MENCA), to measure the atmospheric composition at different altitudes. The sensor measured carbon dioxide, oxygen, nitrogen and carbon monoxide to see how they were distributed at different altitudes.
MOM’s activity at Mars is important for a couple of reasons. Its results confirm the results of other probes that have studied Mars’ atmosphere. And confirmation is an important part of science. But there’s another reason why MOM is important, and this centres around the search for evidence of life on the Red Planet.
Methane is considered a marker for the presence of life. It’s not an absolute indicator that life is or was present, but it’s a good hint. One of MOM’s sensors is the Methane Sensor for Mars (MSM.) Methane has been detected in Mars’ atmosphere before, but these could have been spikes, and not a strong indicator of living processes. If MSM provides stronger data indicating a consistent methane presence, that would be very interesting.
Releasing these results is also vindication for ISRO. In 2008, ISRO released data from their lunar mission, Chandrayaan-1, showing the presence of water on the Moon. Those results, which were gathered with an instrument called Chandra’s Altitudinal Composition Explorer (CHACE) were rejected by several scientific publications, on the grounds that the results were contaminated. Only when they were confirmed by another of Chandrayaan-1’s instruments—the Moon Mineralogy Mapper (M3)—were the results accepted.
But MOM’s MENCA instrument is based on the CHACE instrument aboard Chandrayaan-1, so ISRO feels that MENCA’s success in the atmosphere at Mars vindicates CHACE’s results on the Moon. And rightly so.
You can read a blog post by Syed Maqbool Ahmed at the Planetary Society, where he talks about the success of MOM’s MENCA, and how it vindicates ISRO’s earlier results with CHACE that showed the presence of water on the Moon.
MOM is India’s first interplanetary mission, and is expected to last until its fuel runs out, which could take many years. India is the first Asian nation to make it to another planet, and the first of any nation to make it to Mars on their first attempt. Not bad for a mission that was initially considered to be only a technology demonstration mission.
A team of astronomers from UCLA searched for "technosignatures" in the Kepler field data. Credit and Copyright: Danielle Futselaar
Very recently, a team of scientists from the Commonwealth Scientific and Industrial Research Organization (CSIRO) achieved an historic first by being able to pinpoint the source of fast radio bursts (FRBs). With the help of observatories around the world, they determined that these radio signals originated in an elliptical galaxy 6 billion light years from Earth. But as it turns out, this feat has been followed by yet another historic first.
In all previous cases where FRBs were detected, they appeared to be one-off events, lasting for mere milliseconds. However, after running the data from a recent FRB through a supercomputer, a team of scientists at McGill University in Montreal have determined that in this instance, the signal was repeating in nature. This finding has some serious implications for the astronomical community, and is also considered by some to be proof of extra-terrestrial intelligence.
FRBs have puzzled astronomers since they were first detected in 2007. This event, known as the Lorimer Burst, lasted a mere five milliseconds and appeared to be coming from a location near the Large Magellanic Cloud, billions of light years away. Since that time, a total of 16 FRBs have been detected. And in all but this one case, the duration was extremely short and was not followed up by any additional bursts.
The NSF’s Arecibo Observatory, which is located in Puerto Rico, is the world largest radio telescope. Credit: NAIC
Because of their short duration and one-off nature, many scientists have reasoned that FRBs must be the result of cataclysmic events – such as a star going supernova or a neutron star collapsing into a black hole. However, after sifting through data obtained by the Arecibo radio telescope in Puerto Rico, a team of students from McGill University – led by PhD student Paul Scholz – determined that an FRB detected in 2012 did not conform to this pattern.
In an article published in Nature, Scholz and his associates describe how this particular signal – FRB 121102 – was followed by several bursts with properties that were consistent with the original signal. Running the data which was gathered in May and June through a supercomputer at the McGill High Performance Computing Center, they determined that FRB 121102 had emitted a total of 10 new bursts after its initial detection.
This would seem to indicate that FRBs have more than just one cause, which presents some rather interesting possibilities. As Paul Scholz told Universe Today via email:
“All previous Fast Radio Bursts have only been one-time events, so a lot of explanations for them have involved a cataclysmic event that destroys the source of the bursts, such as a neutron star collapsing into a black hole. Our discovery of repeating bursts from FRB 121102 shows that the source cannot have been destroyed and it must have been due to a phenomenon that can repeat, such as bright pulses from a rotating neutron star.”
The Parkes Telescope in New South Wales, Australia. Credit: Roger Ressmeyer/Corbis
Another possibility which is making the rounds is that this signal is not natural in origin. Since their discovery, FRBs and other “transient signals” – i.e. seemingly random and temporary signals – from the Universe have been the subject of speculation. As would be expected, there have been some who have suggested that they might be the long sought-after proof that extra-terrestrial civilizations exist.
For example, in 1967, after receiving a strange reading from a radio array in a Cambridge field, astrophysicist Jocelyn Bell Burnell and her team considered the possibility that what they were seeing was an alien message. This would later be shown to be incorrect – it was, in fact, the first discovery of a pulsar. However, the possibility these signals are alien in origin has remained fixed in the public (and scientific) imagination.
This has certainly been the case since the discovery of FRBs. In an article published by New Scientistsin April of 2015 – titled “Cosmic Radio Plays An Alien Tune” – writer and astrophysicist Sarah Scoles explores the possibility of whether or not the strange regularity of some FRBs that appeared to be coming from within the Milky Way could be seen as evidence of alien intelligence.
However, the likelihood that these signals are being sent by extra-terrestrials is quite low. For one, FRBs are not an effective way to send a message. As Dr. Maura McLaughlin of West Virginia University – who was part of the first FRB discovery – has explained, it takes a lot of energy to make a signal that spreads across lots of frequencies (which is a distinguishing feature of FRBs).
For decades, scientists have been exploring the possibility that radio bursts are signals from alien civilizations. Credit: AdamBurn/DeviantArt
And if these bursts came from outside of our galaxy, which certainly seems to be the case, they would have to be incredibly energetic to get this far. As Dr. McLaughlin explained to Universe Today via email:
“The total amount of power required to produce just one FRB pulse is as much as the Sun produces in a month! Although we might expect extraterrestrial civilizations to send short-duration signals, sending a signal over the very wide radio bandwidths over which FRBs are detected would require an improbably immense amount of energy. We expect that extraterrestrial civilizations would transmit over a very narrow range of radio frequencies, much like a radio station on Earth.
But regardless of whether these signals are natural or extra-terrestrial in origin, they do present some rather exciting possibilities for astronomical research and our knowledge of the Universe. Moving forward, Scholz and his team hope to identify the galaxy where the radio bursts originated, and plans to use test out some recently-developed techniques in the process.
“Next we would like to localize the source of the bursts to identify the galaxy that they are coming from,” he said. “This will let us know about the environment around the source. To do this, we need to use radio interferometry to get a precise enough sky location. But, to do this we need to detect a burst while we are looking at the source with such a radio telescope array. Since the source is not always bursting we will have to wait until we get a detection of a burst while we are looking with radio interferometry. So, if we’re patient, eventually we should be able to pinpoint the galaxy that the bursts are coming from.”
In the end, we may find that rapid burst radio waves are a more common occurrence than we thought. In all likelihood, they are being regularly emitted by rare and powerful stellar objects, ones which we’ve only begun to notice. As for the other possibility? Well, we’re not saying it’s aliens, but we’re quite sure others will be!
Illustris simulation, showing the distribution of dark matter in 350 million by 300,000 light years. Galaxies are shown as high-density white dots (left) and as normal, baryonic matter (right). Credit: Markus Haider/Illustris
Mapping the Universe with satellites and ground-based observatories have not only provided scientists with a pretty good understanding of its structure, but also of its composition. And for some time now, they have been working with a model that states that the Universe consists of 4.9% “normal” matter (i.e. that which we can see), 26.8% “dark matter” (that which we can’t), and 68.3% “dark energy”.
From what they have observed, scientists have also concluded that the normal matter in the Universe is concentrated in web-like filaments, which make up about 20% of the Universe by volume. But a recent study performed by the Institute of Astro- and Particle Physics at the University of Innsbruck in Austria has found that a surprising amount of normal matter may live in the voids, and that black holes may have deposited it there.
In a paper submitted to the Royal Astronomical Society, Dr. Haider and his team described how they performed measurements of the mass and volume of the Universe’s filamentary structures to get a better idea of where the Universe’s mass is located. To do this, they used data from the Illustris project – a large computer simulation of the evolution and formation of galaxies.
The Big Bang Theory: A history of the Universe starting from a singularity and expanding ever since. Credit: grandunificationtheory.com
As an ongoing research project run by an international collaboration of scientists (and using supercomputers from around the world), Illustris has created the most detailed simulations of our Universe to date. Beginning with conditions roughly 300,000 years after the Big Bang, these simulations track how gravity and the flow of matter changed the structure of the cosmos up to the present day, roughly 13.8 billion years later.
The process begins with the supercomputers simulating a cube of space in the universe, which measures some 350 million light years on each side. Both normal and dark matter are dealt with, particularly the gravitational effect that dark matter has on normal matter. Using this data, Haider and his team noticed something very interesting about the distribution of matter in the cosmos.
Essentially, they found that about 50% of the total mass of the Universe is compressed into a volume of 0.2%, consisting of the galaxies we see. A further 44% is located in the enveloping filaments, consisting of gas particles and dust. The remaining 6% is located in the empty spaces that fall between them (aka. the voids), which make up 80% of the Universe.
However, a surprising faction of this normal matter (20%) appears to have been transported there, apparently by the supermassive black holes located at the center of galaxies. The method for this delivery appears to be in how black holes convert some of the matter that regularly falls towards them into energy, which is then delivered to the sounding gas, leading to large outflows of matter.
Artist’s impression of a supermassive black holes at the hearts of a galaxy. Credit: NASA/JPL-Caltech
These outflows stretch for hundreds of thousands of lights years beyond the host galaxy, filling the void with invisible mass. As Dr. Haider explains, these conclusions supported by this data are rather startling. “This simulation,” he said, “one of the most sophisticated ever run, suggests that the black holes at the center of every galaxy are helping to send matter into the loneliest places in the universe. What we want to do now is refine our model, and confirm these initial findings.”
The findings are also significant because they just may offer an explanation to the so-called “missing baryon problem”. In short, this problem describes how there is an apparent discrepancy between our current cosmological models and the amount of normal matter we can see in the Universe. Even when dark matter and dark energy are factored in, half of the remaining 4.9% of the Universe’s normal matter still remains unaccounted for.
For decades, scientists have been working to find this “missing matter”, and several suggestions have been made as to where it might be hiding. For instance, in 2011, a team of students at the Monash School of Physics in Australia confirming that some of it was in the form of low-density, high energy matter that could only be observed in the x-ray wavelength.
In 2012, using data from the Chandra X-ray Observatory, a NASA research team reported that our galaxy, and the nearby Large and Small Magellanic Clouds, were surrounded by an enormous halo of hot gas that was invisible at normal wavelengths. These findings indicated that all galaxies may be surrounded by mass that, while not visible to the naked eye, is nevertheless detectable using current methods.
And just days ago, researchers from the Commonwealth Scientific and Industrial Research Organization (CSIRO) described how they had used fast radio bursts (FRBs) to measure the density of cosmic baryons in the intergalactic medium – which yielded results that seem to indicate that our current cosmological models are correct.
Factor in all the mass that is apparently being delivered to the void by supermassive black holes, and it could be that we finally have a complete inventory of all the normal matter of the Universe. This is certainly an exciting prospect, as it means that one of the greatest cosmological mysteries of our time could finally be solved.
Now if we could just account for the “abnormal” matter in the Universe, and all that dark energy, we’d be in business!
The globular cluster Messier 5, one of the oldest belonging to the Milky Way. Credit: NASA/ESA/HST
In the late 18th century, Charles Messier was busy hunting for comets in the night sky, and noticed several “nebulous” objects. After initially mistaking them for the comets he was seeking, he began to compile a list of these objects so other astronomers would not make the same mistake. Known as the Messier Catalog, this list consists of 100 objects, consisting of distant galaxies, nebulae, and star clusters.
Among the many famous objects in this catalog is the M5 globular star cluster (aka. NGC 5904). Located in the galactic halo within the Serpens Constellation, this cluster of stars is almost as old as the Universe itself (13 billion years)! Though very distant from Earth and hard to spot, it is a favorite amongst amateur astronomers who swear by its beauty.
Researchers at the CSIRO have managed to pinpoint the location of an FRB for the first time, yielding valuable information about our universe. Credit: csiro.au
In July of 2012, researchers at the CERN laboratory made history when they announced the discovery of the Higgs Boson. Though its existence had been hypothesized for over half a century, confirming its existence was a major boon for scientists. In discovering this one particle, the researchers were also able to confirm the Standard Model of particle physics. Much the same is true of our current cosmological model.
For decades, scientists been going by the theory that the Universe consists of about 70% dark energy, 25% dark matter and 5% “luminous matter” – i.e. the matter we can see. But even when all the visible matter is added up, there is a discrepancy where much of it is still considered “missing”. But thanks to the efforts of a team from the Commonwealth Scientific and Industrial Research Organization (CSIRO), scientists now know that we have it right.
This began on April 18th, 2015, when the CSIRO’s Parkes Observatory in Australia detected a fast radio burst (FRB) coming from space. An international alert was immediately issued, and within a few hours, telescopes all around the world were looking for the signal. The CSIRO team began tracking it as well with the Australian Telescope Compact Array (ATCA) located at the Paul Wild Observatory (north of Parkes).
Image showing the field of view of the Parkes radio telescope (left) and zoom-ins on the area where the signal came from (left). Credit: D. Kaplan (UWM), E. F. Keane (SKAO).
With the help of the National Astronomical Observatory of Japan’s (NAOJ) Subaru telescope in Hawaii, they were able to pinpoint where the signal was coming from. As the CSIRO team described in a paper submitted to Nature, they identified the source, which was an elliptical galaxy located 6 billion light years from Earth.
This was an historic accomplishment, since pinpointing the source of FRBs have never before been possible. Not only do the signals last mere milliseconds, but they are also subject to dispersion – i.e. a delay caused by how much material they pass through. And while FRBs have been detected in the past, the teams tracking them have only been able to obtain measurements of the dispersion, but never the signal’s redshift.
Redshift occurs as a result of an object moving away at relativistic speeds (a portion of the speed of light). For decades, scientists have been using it to determine how fast other galaxies are moving away from our own, and hence the rate of expansion of the Universe. Relying on optical data obtained by the Subaru telescope, the CSIRO team was able to obtain both the dispersion and the redshift data from this signal.
As stated in their paper, this information yielded a “direct measurement of the cosmic density of ionized baryons in the intergalactic medium”. Or, as Dr. Simon Johnston – of the CSIRO’s Astronomy and Space Science division and the co-author of the study – explains, the team was not only to locate the source of the signal, but also obtain measurements which confirmed the distribution of matter in the Universe.
“Until now, the dispersion measure is all we had,” he said. “By also having a distance we can now measure how dense the material is between the point of origin and Earth, and compare that with the current model of the distribution of matter in the Universe. Essentially this lets us weigh the Universe, or at least the normal matter it contains.”
Dr. Evan Keane of the SKA Organization, and lead author on the paper, was similarly enthused about the team’s discovery. “[W]e have found the missing matter,” he said. “It’s the first time a fast radio burst has been used to conduct a cosmological measurement.”
As already noted, FRB signals are quite rare, and only 16 have been detected in the past. Most of these were found by sifting through data months or years after the signal was detected, by which time it would be impossible for any follow-up observations. To address this, Dr. Keane and his team developed a system to detect FRBs and immediately alert other telescopes, so that the source could be pinpointed.
Artists impression of the SKA-mid dishes in Africa shows how they may eventually look when completed. Credit: skatelescope.org
It is known as the Square Kilometer Array (SKA), an international effort led by the SKA Organization to build the world’s largest radio telescope. Combining extreme sensitivity, resolution and a wide field of view, the SKA is expected to trace many FRBs to their host galaxies. In so doing, it is hoped the array will provide more measurements confirming the distribution of matter in the Universe, as well as more information on dark energy.
In the end, these and other discoveries by the SKA could have far-reaching consequences. Knowing the distribution of matter in the universe, and improving our understanding of dark matter (and perhaps even dark energy) could go a long way towards developing a Theory Of Everything (TOE). And knowing how all the fundamental forces of our universe interact will go a long way to finally knowing with certainty how it came to be.
These are exciting time indeed. With every step, we are peeling back the layers of our universe!
The constellation Apus, located in the Southern Hemisphere. Credit: astropixels.com
Welcome back to Constellation Friday! Today, we will be dealing with the beautiful bird-of-paradise itself, the Apus constellation!
The Southern Hemisphere is replete with beautiful stars and constellations, enough to keep a stargazing enthusiast busy for a lifetime. For countless centuries, the indigenous peoples of South America, South Africa, Australia and the South Pacific have looked up at these stars and drawn inspiration. However, to European astronomers, they remained uncharted and unknown until the 16th century.
It was during this time that Flemish astronomer Petrus Plancius designated twelve constellations, using asterisms found in the southern skies. One such constellation was Apus, a faint constellation in the southern sky that is named for the bird-of-paradise – a beautiful bird that is indigenous to the South Pacific. Today, it is one of the 88 constellations defined by the International Astronomic Union (IAU).
Name and Meaning:
The name Apus is derived from Greek word apous, which literally means “no feet”. The name applies to a species of bird that is indigenous to Indonesia, Papua New Guinea, and Eastern Australia (which was believed at one time to have no feet). Its original name on Plancius’ charts was “Apis Indica” – the Latin term for “Indian Bee” (presumably an error for “avis”, which means bird).
This faint southern constellation of Apus was one of the original twelve created by Plancius, based on observations provided by Pieter Dirkszoon Keyser and Frederick de Houtman – two Dutch explorers/navigators who mapped the southern sky around Australia between 1595 and 1597.
It was included on a celestial globe published in 1597 or 1598 in Amsterdam by Plancius and his associate, Flemish cartographer and engraver Jodocus Hondius. After it’s introduction on Plancius’ globe, it also appeared in Uranometria, a star atlas published by Johann Bayer – a German celestial catrographer – in 1603.
Here, it appeared under the name “Apis Indica”. It also grouped with the other members of the “Johann Bayer family” of constellations, all of which appeared in Uranometria. These include Chamaeleon, Dorado, Grus, Hydrus, Indus, Musca, Pavo, Phoenix, Tucana, and Volans. The constellation also appears as part of the Chinese constellations, where it is known as the “Little Wonder Bird”.
In the 17th century, Ming Dynasty astronomer Xu Guangqi adapted the European southern hemisphere constellations when producing The Southern Asterisms. Combining Apus with some of the stars in Octans, he designated the stars in this area of the night sky into the constellation known as Yìquè (“Exotic Bird”). In 1922, Apus was included by the International Astronomical Union in the list of 88 constellations.
The southern constellation Apus and neighboring Deep Sky Objects. Credit: absoluteaxarquia.com
Notable Features:
Within the Apus constellation, there are 39 stars that are brighter than or equal to apparent magnitude 6.5. The most notable of these is Alpha Apodis. an orange giant star with a magnitude of 3.8, located roughly 411 light years away from Earth. Beta Apodis is also an orange giant, with a magnitude of 4.2. and located 158 light years from Earth. And Gamma Apodis , another orange giant, has a magnitude of 3.9 and is located 160 light years away.
Delta Apodis is a binary star system consisting of a red giant and an orange giant. Delta¹ has a magnitude of 4.7 and is located 765 light years away, while Delta² has a magnitude of 5.3 and is located 663 light years away. Then there is Theta Apodis, a variable red giant star with a maximum magnitude of 4.8 and a minimum of 6.1 that is located 328 light years away.
NO Apodis is a red giant that varies between magnitudes 5.71 and 5.95 and is located around 883 light-years away from Earth. This star shines with a luminosity that is approximately 2059 times greater than our Sun’s and has a surface temperature of 3568 K.
Apus is also home to a few Deep Sky Objects. These include the IC 4499 loose globular cluster (shown below), which is located in the medium-far galactic halo and has an apparent magnitude of 10.6. This object is rather unique in that its metallicity readings indicate that it is younger than most other globular clusters in the region.
NASA/ESA Hubble Space Telescope image of the globular cluster IC 4499, located in the Apus constellation. Credit: ESA/NASA/HST
Then there’s NGC 6101, a 14th mangitude globular cluster located seven degree north of Gamma Apodis. Last, there is the spiral galaxy IC 4633, which is very faint due to its location well within the Milky Way’s nebulous disc.
Finding Apus:
For binoculars, take a look at Alpha Apodis. This 3.8 magnitude star is located 411 light years away from Earth. Now move on to Delta. It is a wide double star which is two orange 5th-magnitude members separated by 103 arc seconds and an easy split. Or try observing Theta – its a variable star whose brightness ranges from magnitude 4.8 to 6.1 in a period of 109 days.
For telescopes, take a look at more difficult binary star Kappa-1 Apodis. The brightest component of this disparate pair has a magnitude of 5.4 and the companion is 12th magnitude, 27 arcseconds away. Need more? Then turn your gaze towards Kappa-2 only 0.63 degrees from Kappa-1. Kappa-1 Apodis is a binary star approximately 1020 light years from Earth. The primary component, Kappa-1 Apodis A, is a blue-white B-type subgiant with a mean apparent magnitude of +5.40. It is classified as a Gamma Cassiopeiae type variable star and its brightness varies from magnitude +5.43 to +5.61. The companion star, Kappa-1 Apodis B, is a 12th magnitude orange K-type subgiant. It is 27 arc seconds from the primary.
For larger telescopes, wander off and look at NGC 6101 located about seven degrees north of Gamma. Here we have a small, 14th magnitude globular cluster! If you’re really good you can try for spiral galaxy IC 4633. It’s so faint it doesn’t even have a magnitude listing!
Artist’s impression of the planet around Alpha Centauri B. Credit: ESO
On July 14th, 2015, the New Horizons space probe made history when it became the first spacecraft to conduct a flyby of the dwarf planet of Pluto. Since that time, it has been making its way through the Kuiper Belt, on its way to joining Voyager 1 and 2 in interstellar space. With this milestone reached, many are wondering where we should send our spacecraft next.
Naturally, there are those who recommend we set our sights on our nearest star – particularly proponents of interstellar travel and exoplanet hunters. In addition to being Earth’s immediate neighbor, there is the possibility of one or more exoplanets in this system. Confirming the existence of exoplanets would be one of the main reasons to go. But more than that, it would be a major accomplishment!
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:
An imagined view from Planet Nine looking back toward the Sun. Astronomers think the massive, distant planet is gaseous, similar to the other giant planets in our Solar System. Credit: Wikipedia
Last month, planetary scientists Mike Brown and Konstantin Batygin of the California Institute of Technology found evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer Solar System. Nicknamed Planet Nine, it’s estimated to be 10 times more massive than Earth with a diameter as large as 16,000 miles (25,750 km). The putative planet orbits about 20 times farther from the Sun on average than Neptune or some 56 billion miles away; at that tremendous distance it would take between 10,000 and 20,000 years to complete one orbit around the Sun.
The six most distant known objects in the Solar System with orbits exclusively beyond Neptune (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. Batygin and Brown showed that a planet with 10 times the mass of the earth in a distant eccentric orbit anti-aligned with the other six objects (orange) is required to maintain this configuration. Credit: Caltech/R. Hurt (IPAC); Diagram created using WorldWide TelescopePlanet Nine’s existence is inferred through mathematical modeling and computer simulations based on the clustering of six remote asteroids in the Kuiper Belt, a vast repository of icy asteroids and comets beyond Neptune. Brown and Batyginsay there’s only a 0.007% chance or about 1 in 15,000 that the clustering could be a coincidence.
All well and good. But with such an enormous orbit, astronomers face the daunting task of searching vast swaths of space for this needle in a haystack. Where to begin? A study done by a team of French scientists may help narrow the search. In a recent paper appearing in Astronomy and Astrophysics, astronomerAgnes Fienga and colleagues looked at what effect a large Kuiper Belt planet would have on the orbits of other planets in the Solar System, focusing their study on Saturn. Thanks to NASA’s Cassini orbiter, which has been orbiting Saturn since 2004, we can precisely calculate Saturn’s position along its orbit.
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 , created by the author
Based on the planet’s “residuals”, the difference between the calculated position of Saturn versus what was actually observed, the team was able to exclude two sections of its potential orbit and home in on “probable” swath and a much larger “possible” section of the orbit. The process may sound familiar, since it was the one used to discover another planet more than 150 years ago — Neptune. Back then, irregularities (residuals) in the motion of Uranus led astronomers in 1847 to predict a more distant 8th planet as the cause. On September 24, 1846, Johann Galle discovered Neptune only 1° from its position predicted by French mathematician Urbain LeVerrier.
While the current solution for Planet Nine doesn’t come anywhere near as close, it’s a step in the right direction.
![The six most distant known objects in the solar system with orbits exclusively beyond Neptune (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. Batygin and Brown show that a planet with 10 times the mass of the earth in a distant eccentric orbit anti-aligned with the other six objects (orange) is required to maintain this configuration. Credit: Caltech/R. Hurt (IPAC); [Diagram created using WorldWide Telescope.]](https://www.universetoday.com/wp-content/uploads/2016/01/Planet-nine.jpg)
