How A Passing Star Lit Up The Ancient Sky

Posted on November 19, 2019 in Uncategorized

For millions of years all human beings, both early and modern, had to find their own food, and were forced to spend most of each day gathering plants and hunting animals in order to survive. Then, within only the past 12,000 years, our species made the revolutionary transition from being hunters and gatherers, to being able to produce our own food. Nevertheless, about 74,000 years ago, modern humans almost became extinct as a result of dramatic climate changes, and the human population may have been reduced to only about 10,000 adults of reproductive age. It was around this time, approximately 70,000 years ago, that a small reddish star floated close to our Solar System and gravitationally shook up comets and asteroids–sending them screaming inward towards our young Sun. In March 2018, a team of astronomers from the Complutense University of Madrid in Spain and the University of Cambridge in England announced that they have verified that the movement of some of these comets and asteroids was effected by that close stellar encounter.

At a time when modern humans were first beginning to migrate from Africa, and Neanderthals were dwelling with them on Earth, Scholz’s star–named after the German astronomer who discovered it–floated less than one light-year from our Sun. Currently, this little red star is almost 20 light-years away, but 70,000 years ago it created a disaster when it wandered into our Solar System’s Oort Cloud, a remote reservoir of trans-Neptunian objects (TNOs) located at the outer limits of our Solar System. TNOs are icy and dusty comet nuclei that dwell in the distant dark deep freeze of our Sun’s region of gravitational influence.

This discovery was first made public in 2015 by a team of astronomers led by Dr. Eric Mamajek of the University of Rochester in New York (USA). The details of that catastrophic stellar flyby, the closest documented so far, were published in the February 10, 2015 issue of The Astrophysical Journal Letters.

Stellar Ships That Passed In The Night

Our Sun is a solitary star, but even though it lives alone, it sometimes has visitors. Such a visitor was the dim and alien Scholz’s star when it paid our Solar System a visit. This faint, small stellar invader is thought to have skimmed through the Oort Cloud–the remote shell of comet nuclei that surrounds our entire Solar System.

Scholz’s star is a low-mass red dwarf star that is a member of a binary system, and it sports the puny mass of merely 8% that of our Sun. The other member of the duo is a brown dwarf, a failed star, that is even smaller than Scholz’s star with a mass of only 6% solar masses. Red dwarf stars are the smallest true stars in the Cosmos, as well as the most numerous and longest-lived. In contrast, puny little brown dwarfs are fascinating little stellar failures. This is because, even though brown dwarfs are likely born the same way as true stars–from the collapse of an especially dense blob of material embedded within one of the many giant, dark, and frigid molecular clouds that haunt our Milky Way Galaxy–they never manage to gain sufficient weight to ignite their nuclear-fusing star-fire. Even though puny little brown dwarfs never acquire sufficient mass to begin the process of nuclear fusion, they are still more massive than gas giant planets, such as our own Solar System’s spotted and banded behemoth, Jupiter. Red dwarf stars, in contrast, did manage to acquire enough mass to begin the process of nuclear fusion–which produces sufficient pressure to battle against the force of gravity, thus keeping the star bouncy against its own fatal collapse. Radiation pressure pushes the stellar material out and away from the star, while gravity tries to squeeze everything in. The two warring forces help a star maintain stellar equilibrium–but the end must come, sooner or later. As soon as the star finishes burning its necessary supply of nuclear-fusing fuel–whereby it fuses heavier atomic elements out of lighter ones–gravity wins the war against its rival, and the star collapses. However, it is likely that there are no dead red dwarf stars in the Cosmos–yet. Small stars take their stellar “lives” easy and burn their fuel–very, very slowly. Indeed, it probably takes trillions of years for a red dwarf to perish, and our Universe isn’t even 14 billion years old yet. In contrast, massive stars live fast and die young, and some may only “live” for millions, as opposed to billions–let alone trillions–of years. Our Sun is a small star, but it is much more massive than a red dwarf. Our Star is approximately 4.56 billion years old, and it has about another 5 billion years to go before it blows off its outer gaseous layers, leaving its relic core behind in the form of a tiny dense object called a white dwarf.

Scholz’s star is an inhabitant of the Monoceros constellation, which is located about 20 light-years from Earth. However, when the tiny faint red dwarf closely brushed our young Solar System in Earth’s prehistory thousands of years ago, it would have appeared as a 20th magnitude star. This is about 50 times more faint than can usually be seen with the naked human eye at night. However, Scholz’s star is very magnetically active, and this can make it “flare”. For one brief shining moment on a cosmological time scale, Scholz’s star can potentially become thousands of times brighter. This means that it is entirely possible that Scholz’s star was visible to our prehistoric ancestors 70,000 years ago–for minutes or hours at time during its rare episodes of flaring.

Scholz’s star is more formally designated WISE J072003.20-084651.2. It derived its less technical nickname to honor the astronomer Dr. Ralf-Dieter Scholz of the Leibniz-Institut fur Astrophysik Potsdam (AIP) in Germany. Dr. Scholz is the first to have announced the discovery of the dim little red dwarf star late in 2013. The WISE component of Scholz’s star’s formal name refers to NASA’s Wide-field Infrared Survey Explorer (WISE) mission, responsible for mapping the entire sky in infrared light in 2010 and 2011. The J part of the formal designation refers to the red dwarf’s coordinates.

The little star’s trajectory suggests that 70,000 years ago it floated about 52,000 astronomical units (AU) from Earth (0.8 light-years)–which is equal to 5 trillion miles. One AU is equivalent to the average distance between the Sun and Earth, which is about 93,000,000 miles. The authors of the 2015 paper noted that they are 98% certain that Scholz’s star skimmed the Oort Cloud, a mysterious and unexplored domain situated at the edge of our Solar System. The Oort Cloud is generally thought to be the home of trillions of frozen, glittering, icy comet nuclei that are about a mile–or more–across. This distant cloud is also thought to be the origin of long-period comets that swing into orbit around our Sun after their orbits have been gravitationally disrupted.

The Oort Cloud is named for its two discoverers, the Dutch astronomer Jan Oort (1900-1992) and the Estonian astronomer Ernst Opik (1893-1985). This spherical shell is the habitat of icy planetesimals, left over from our Solar System’s formation more than 4.5 billion years ago. Icy planetesimals were the building blocks of the quartet of giant gaseous planets inhabiting the outer Solar System–Jupiter, Saturn, Uranus, and Neptune. In contrast, the asteroids–mostly found inhabiting the Main Asteroid Belt between Mars and Jupiter–are the relic population of rocky and metallic planetesimals that built up the quartet of solid inner Solar System planets–Mercury, Venus, Earth, and Mars. In the primeval Solar System planetesimals–both icy and rocky–collided with one another and merged to create ever larger and larger bodies, thus forming the familiar planets of our Sun’s family. The Oort Cloud is thought to surround our Solar System at a distance of as much as 100,000 AU, which situates it half-way to the nearest star to our Sun, which is Proxima Centauri.

The Kuiper Belt and Scattered Disk–which also house frozen comet-like objects–are less than one thousandth as far from our Sun as the Oort Cloud. The outermost edge of the Oort Cloud marks the boundary of our Star’s region of influence. It is the boundary of our Sun’s gravitational dominance.

The Oort Cloud is generally believed to be composed of two regions: a disk-shaped inner cloud called the Hills cloud, and a spherical outer cloud. Most of the remote, frozen inhabitants of the Oort Cloud are made up of ices, such as water ice, methane ice, and ammonia ice.

Our Sun was probably born as a member of a dense open stellar cluster containing thousands of sibling stars. Many astronomers believe that our newborn Sun was either unceremoniously evicted from its natal cluster as the result of gravitational perturbations caused by other stars, or that it simply floated away of its own free will about 4.5 billion years ago. Our Star’s stellar siblings have long since wandered off to more distant regions of our Milky Way Galaxy, and there very well may have been as many as 3,500 of these nomadic solar-siblings.

Today, our Sun is in active mid-life. It is a main-sequence (hydrogen-burning) star on the Hertzsprung-Russell Diagram of Stellar Evolution. As stars go, our Sun is not particularly special. Our Solar System is located in the far suburbs of our majestic–though typical–barred-spiral Galaxy, the Milky Way.

Shining In The Prehistoric Sky

Two astronomers from the Complutense University of Madrid (Spain), the brothers Dr. Carlos and Dr. Raul de la Fuente Marcos, along with their colleague Dr. Sverre J. Aarseth of the University of Cambridge (UK), have now analyzed, for the first time, the nearly 340 objects objects dwelling in our Solar System with hyperbolic orbits (very open V-shaped, as opposed to the typical elliptical). In the process, the three astronomers discovered that the trajectory of some of these objects are influenced by the passage of Scholz’s star.

“Using numerical simulations we have calculated the radiants or positions in the sky from which all these hyperbolic objects seem to come,” explained Dr. Carlos de la Fuente Marcos in a March 10, 2018 La Ciencia es Noticia (SiNC) Press Release.

“In principle, one would expect those positions to be evenly distributed in the sky, particularly if these objects come from the Oort Cloud. However, what we find is very different, a statistically significant accumulation of radiants. The pronounced over-density appears projected in the direction of the constellation of Gemini, which fits the close encounter with Scholz’s star,” he continued to note.

The exact time in which Scholz’s star passed close to Earth, as well as its position during prehistory, coincide with the date determined in the new investigation–and also with those calculated by Dr. Mamajek and his team. “It could be a coincidence, but it is unlikely that both location and time are compatible,” Dr. De la Fuente Marcos continued to explain in the March 10, 2018 SiNC Press Release. He further pointed out that their simulations indicate that Scholz’s star approached even closer than the 0.6 light-years proposed in the earlier 2015 study as the lower limit.

This close brush with the little red star 70,000 years ago did not disrupt all of the hyperbolic objects in our Solar System, only those that were closest to it at that time. “For example, the radiant of the famous interstellar asteroid Oumuamua is in the constellation of Lyra (the Harp), very far from Gemini. Therefore, it is not part of the detected over-density,” Dr. De la Fuente Marcos added. He further said that he is confident that new studies and observations will confirm the idea that Scholz’s star passed close to us in relatively recent times. Indeed, it is likely that are ancestors, gazing up at the sky, saw its dim reddish light in the dark nights of prehistory.

You Have Title to Your Property – So What! Eminent Domain – Government’s Right to Take What’s Yours

Posted on November 18, 2019 in Uncategorized

The U.S. Constitution Fifth Amendment states: “…nor shall property be taken for public use without just compensation.”

The taking of property for public use is a necessary power of any government at any level. Without the power, there could be no public roads, parks, utility easements or other public uses. The big question of just what is public use came before the Supreme Court in 2005 with Kelo v. City of New London, one of the most controversial decisions in recent memory. The City of New London determined that an area of the city, Fort Trumbull, needed to be revitalized and redeveloped to fit in with the plans of drug giant Pfizer, Inc. which intended to create a large nearby research facility. The city condemned the property of plaintiff Kelo and four others who did not want to sell their property. The area in question was by no means blighted, or even run-down. It just got in the way of a redevelopment plan. The area in question was about 5 1/2 acres out of a total of 90 acres. Plaintiffs argued that the plan would take their private property and transfer it to another private entity, the developer, and that this did not constitute a public use. The 5-4 majority, with Justice Kennedy providing the swing vote, held in favor of the city, finding that the action constituted a public use. Justice Sandra Day O’Connor issued a strong dissent, joined by Justice Antonin Scalia. She found that the decision effectively deletes the words “for public use” from the Takings Clause of the Fifth Amendment.

One commentator estimated that in the first year after the Kelo decision local governments used the threat or actually did condemn over 5,683 private parcels for transfer to other private parties. This shows the enormous power of a Supreme Court decision. Since the founding of the republic, all levels of government operated on the assumption that the taking of property for public use, actually meant for public use. Public use meant roads, utility easements, military installations, and the like. Nobody thought that a public use could mean a private use that government, in its wisdom, determines to be a better use than the current one.

Judge Richard Posner takes an interesting view of the case, finding the decision pragmatic because the storm of controversy the case unleashed resulted in a very democratic response. Posner is considered the leader of the pragmatic school of decision-making. “When the court declines to invalidate an unpopular government power, it tosses the issue back into the public arena.” I find Judge Posner’s take on this case a little troubling. Shall we call a “pragmatic” decision like Kelo a “Freak-out Decision” as in: “This will really cause everybody to freak out and will be good for the democratic process in the long run.”

It is difficult to determine what is a public use, when the use in question is by a private party. The debate over government’s right to take private property will go on for a long time. The decision in Kelo V. City of New London and its controversial view of just what is a public use had lit a fire under the issue.

[Top]

Neptune: Our Solar System’s Gentle Giant

Posted on November 17, 2019 in Uncategorized

In the perpetual twilight of our Solar System’s outer limits, our Sun shines with merely a feeble, distant fire, and appears to be only an especially large star, swimming in a sea of countless other silvery, sparkling stellar lights. When our Solar System was first forming, about 4.6 billion years ago, strange things were occurring. Newborn planetary building blocks–called planetesimals–migrated from where they originated, and blasted into one another, sometimes merging, but sometimes crashing together catastrophically–shattering one another into fragments. The ice-giant, beautiful, big, banded blue Neptune–the most distant of the eight major planets from our Sun–is known to have exerted an influence on our baby Solar System, as it wandered through this primordial “cosmic shooting gallery.” In April 2017, astronomers announced that they had made a major discovery concerning the mysterious birth and evolution of icy bodies in our Solar System’s remote, frozen Kuiper Belt–the home of a myriad of dancing comet nuclei beyond the orbit of Neptune. The astronomers said that they had unlocked unique evidence that Neptune’s migration during the era of ancient planet formation, in our young Sun’s domain, was a “smooth and calm” journey–and not the rampage of a fierce giant, as had been previously suggested in other studies.

“It’s a kinder, gentler Neptune,” commented astronomer Dr. Meg Schwamb in an April 4, 2017 Gemini Observatory Press Release. Dr. Schwamb continued to explain that the new result leaves little doubt that Neptune’s migration through the primeval Solar System was a benevolent and gentle sweep–rather than the violent and catastrophic rampage of a big bully.

The study focused on strange “oddball” duos of loosely bound objects, called planetoids, inhabiting the deep freeze of the dimly lit outer regions of our Solar System. The astronomers propose, in a paper published in the April 4, 2017 issue of the journal Nature Astronomy, that these loosely bound objects were probably shepherded by Neptune’s gentle gravitational pushes into their current orbits in the dark and distant Kuiper Belt.

The research team, led by Dr. Wes Frazier of Queen’s University in Belfast, UK, studied data obtained from the Gemini North Frederick C. Gillett Telescope and Canada-France-Hawaii Telescope (CFHT). Both telescopes are poised upon the dormant Mauna Kea volcano in Hawaii. The team measured the colors of “oddball” new Cold Classical Kuiper Belt Object (CCKBO) duos as part of the Colors of the Outer Solar System Origins Survey (CoL-OSSOS).

The “oddball” objects are members of a class of mysterious bodies called “blue binaries”, which are intriguing sibling pairs, doing a distant dance in the outer limits. Blue binaries are “odd” because, like other nonconformists, they travel to the beat of a different drum than their neighbors. This is because blue binaries do not display the distinctive red color that characterizes the surfaces of most CCKBOs.

The remote Kuiper Belt is the frozen home of a dancing swarm of icy small planetoids–well beyond the orbit of beautiful, blue Neptune. The planetoids are comet nuclei–the lingering relics of the building blocks (planetesimals) of the quartet of giant, gaseous planets inhabiting the outer Solar System: Jupiter, Saturn, Uranus, and Neptune. Indeed, this distant belt hosts over 1,700 known icy objects.

Many planetary scientists have long suggested that the frozen, left-over planetoids were born in the very heart of the Kuiper Belt. However, Dr. Fraser’s new study indicates something else–that the blue binaries actually were born in a region situated much closer to the warmth and heat of our Star, and were then shepherded by Neptune’s gravitational nudges into the distant orbits that we see today. This strange migration would have occurred several billions of years ago.

Dancing In The Dark

Distant, dark, and cold, the icy denizens of the Kuiper Belt do their alien ballet in our Solar System’s distant suburbs. Here, the ice dwarf planet Pluto and its quintet of moons dwell along with a multitude of others of their weird and frigid kind. This remote domain is so far from Earth that astronomers are only now first beginning to explore it, thanks to the historic voyage to the Pluto system by NASA’s New Horizons spacecraft, that arrived there on July 14, 2015. New Horizons is now speedily en route to yet another denizen of the deep freeze, and will discover more and more of the as-yet-unanswered mysteries belonging to this dimly lit domain of frozen small worlds.

Therefore, poor Pluto is just one of a large number of similar icy objects in the Kuiper Belt. Discovered in 1930 by the American astronomer Clyde Tombaugh (1906-1997), Pluto was initially classified as the ninth major planet from our Sun. Alas, for little Pluto, astronomers eventually came to the realization that Pluto is just one of many–very many. For this reason, the International Astronomical Union (IAU), was forced to define the term “planet” and, as a result, Pluto was demoted from major planet status to dwarf planet status.

When comets come screeching from our Solar System’s outer limits, into the inner Solar System’s warm, welcoming, melting heat, they make dramatic spectacles of themselves with brilliant tails thrashing–as they flash their mysterious light through the sky. These frozen migrating, alien bodies hold captive–in their icy hearts–the most pristine of primordial ingredients that, long ago, went into the construction of our Sun’s family of objects. This very ancient mixture, of the purest material, has been preserved in the deep-freeze of our Solar System’s dark, distant, and very cold outer regions. These frozen, alien, and fragile visitors from far away fly into the inner Solar System, where our Earth is located, from their mysterious, murky home beyond Neptune. Because comets hold, in their frozen hearts, the well-preserved ancient elements that made our Solar System, many astronomers think that by identifying these ingredients, they can determine how our Sun and its family came to be.

Comets are similar to the rampaging, relic icy planetesimals that merged together in the ancient Solar System to form the four outer gas giants. Alternatively, the asteroids–that primarily inhabit the Main Asteroid Belt between Mars and Jupiter–are similar to the rocky and metallic planetesimals that bumped into one another and merged to form the quartet of small, inner, rocky planets: Mercury, Venus, Earth, and Mars. Planetesimals–both icy and rocky–blasted into one another in the “shooting gallery” that characterized our baby Solar System. These ancient colliding objects merged to create ever larger and larger bodies.

Many astronomers believe that the “oddball” blue binaries migrated from their birthplace–closer to our Sun’s warmth and light–out into the frigid twilight of the distant Kuiper Belt. It is generally proposed that this migration occurred several billion years ago, at a time when profound changes were occurring in the orbits of the quartet of outer, gaseous, giant planets.

“The red CCKBOs are thought to have formed at the location in the outer Solar System where they currently reside. The blue binaries, on the other hand, are interlopers from closer in hiding out in the Kuiper Belt today,” Dr. Schwamb, a coauthor on the study, explained in the April 4, 2017, Gemini Observatory Press Release.

Neptune: Our Solar System’s Gentle Giant

Dr. Fraser’s study suggests that when Neptune migrated from 20 AU to its present location, at 30 AU, it did so with a gentle, slow, peacefulness–a dignified calm voyage, unlike the invading rampage of a violent bully. One AU (astronomical unit) is equivalent to Earth’s average distance from our Sun, which is 93,000,000 miles. This gentle march of the beautiful, blue, and banded ice giant planet, allowed the delicate, fragile, and loosely bound blue binaries to be tenderly nudged out to a similar distance, where they are observed today. This smooth and peaceful migration enabled the blue binaries to make their long journey, into the outer limits, without being torn apart into two separate single objects.

“This research has opened the window to new aspects of understanding the early stages of planet growth. We now have a solid handle on how and where these blue binaries originated,” Dr. Fraser explained in an April 4, 2017 Queen’s University Press Release.

“There has been some evidence around how Neptune moved outwards to 30 AU. Our hypothesis about how these blue binaries came to be where they are requires that Neptune’s migration was largely a smooth and calm movement,” he added.

Dr. Schwamb also explained in the Queen’s University Press Release that “This novel program uses two world-class telescopes: the Gemini-North and Canada-France-Hawaii telescopes, simultaneously. In doing so, we are able to gather comprehensive spectral information spanning the ultra-violet, optical, and near-infrared wavelength ranges. Without this program and the partners involved, this major research breakthrough would not have been possible.”

“Working closely together, Gemini North and the Canada-France-Hawaii telescopes coordinated their movements to observe the Col-OSSOS Kuiper Belt Objects at nearly the same time,” Dr. Schwamb added.

The simultaneous observations on Mauna Kea enabled the team of astronomers to measure the light emanating from the same side of the Kuiper Belt Object. This eliminated one of the most perplexing difficulties in studying Solar System bodies that rotate.

Dr. Todd Burdullis, QSO operations specialist at CFHT, who helped to co-ordinate the observations, commented in the April 4, 2017 Queen’s University Press Release that “Facilitating the simultaneous observations with the Col-OSSOS team and Gemini Observatory was challenging, but paved the way for a greater understanding of the origins of these blue binaries. In tandem, the two facilities observed all the colors of the outer Solar System for the Col-OSSOS team.

[Top]