Here we are again, back at DPS and this time with something quite surprising to say the least...How I would like to be a fly to witness the reactions in the room where spacEurope guest, Patryk Sofia Lykawka, from the Graduate School of Science of Kobe University, presents, tomorrow, is work indicating one direction: Nothing more nothing less than the existence of a planet with the diameter of the Earth and tenths its mass in the outer edge of the Kuiper Belt…
Surprised? Sceptic? Curious?
This is an hypothesis that has, undoubtfuly, the courage to venture through new territories…let us read what his proponent, while travelling through the history of our solar system, can tell us.
This is quite an astonishing announcement to be digested easily so I asked Lykawka if he could place us, unadvised space exploration followers, in the ground where his proposal gives its steps.
He didn’t say no to the challenge and embarked, taking us, readers, on a journey to his Universe.
(As this Q’n’A was made in my native language, Portuguese, being subsequently translated, I request you, dear reader, to indicate me if you find some error).
According to his explanation the most accepted theory of planetary formation predicts that planets are formed via the accretion of planetesimals, which are the minor objects arising in the first million years of the solar system, and then distributed on a protoplanetary disk (which is, on its own, composed by countless planetesimals).
In the first instants after the formation of the giant planets, these were still immersed in the protoplanetary disk along with the presence of a remaining population of planetesimals, among which were tenths or hundreds of objects with considerable masses (in the order of some 1/10 the mass of the Earth). The last episode of planetary formation it’s, following the astronomer thoughts, the “cleaning” of the regions closer to the orbit of the giant planets.
In other words we might say that planets become so massive that they eject, due to gravitational scattering, the nearby planetesimals.
What does the investigator proposes? Following his theory, one of the mentioned planetesimals with higher mass (let’s say…half Earth’s mass), originally ejected from the region where Uranus and Neptune were formed, disturbed the primordial Kuiper Belt for a period of, approximately, 100 million years and then acquired a inclined, far and stable orbit, what permitted its survival for more than 4 billion years in the outskirts of the solar system.
This massive planetesimal would be, now, at this moment in the history of the Solar System,
orbiting the Sun at a distance of, at least, 100 AU, or, simplifying, 3 to 4 times more distant from our star than Pluto.
A far, massive, transplutonian planet in the Lykawka’s description who remarks the importance that the orbital evolution of this planet may be the key to answer several unexplained enigmas of the Kuiper Belt, among which he points out a few…:
The excitation actually observed in the region between 40 and 50 AU is one, another are the populations of different types of objects in the Belt and their orbital characteristics.
Another two pieces of the puzzle can also be put into place under Patryk work: the Belt’s truncated region in the 48 AU region and its small total mass.
The model to be presented by the astronomer at the 39th DPS is, as he tell us, divided in three principal phases regarding the solar system history right after the formation of the giant planets:
We have a first period with an extension of 100 million years where the modelled planet excited and truncated the Kuiper Belt, then, on period II, the giant planets migrated and transported the planet (that I will start naming now for easier identification in the article, as Aernus, the divinity of the Zoelae, an ancient Portuguese tribe located in Trás-os-Montes, the most remote corner of our territory) to an inclined outer orbit through resonant interactions with Neptune (this “age” lasted some hundred million years) and, reaching period III, we find the development of the outer solar system with this planets and the Belt for around more 4 billion years.
Never read something like this? For me it is a première…that is why I asked … if this is the first time a scenario is proposed in this terms, the astronomer puts it like this, in spite of the idea of a planet beyond Pluto being not new (with Planet X leading the parade), this scenario, as presented, is completely new. Our guest states, confidently, that the results obtained by his model invalidate all the previous scenarios based on Planet X’s ideas…and that with an exclamation mark…like this “!”
Returning to more peaceful waters Lykawka tells us that this is the first time that the idea of a planet, being gravitationally exiled from the Uranus-Neptune region and surviving to tell the story, is proposed.
So…where is it? If there were detected other smaller bodies beyond Pluto why was a planet with this mass never detected? Here’s why under spacEurope’s guest view…there are two main reasons being the first the fact of the planet being bright due to its big size and possessing a reasonably reflective surface, but he points out that bright objects in the solar system are rare in the sky…so? To find them we need to observe large areas, this is what is made by wide area surveys.
The detail accuracy that mostly all surveys taken so far possess a limited sensitivity to detect the apparent motion of such objects in the sky (around 1.5arcsec/h).
In his theory, the planet would be, at least, at an average distance of 100 AU, implying motions smaller than the mentioned 1.5arcsec per hour.
The second reason is linked to the planet’s orbital inclination between 20 and 45 degrees.
Why? Under this configuration Aernus would pass close to the solar system plane during only 1-4% of its orbit. As all the surveys made so far studied regions usually close to that level, they had very reduced chances of detecting any planets with more inclined orbits.
Lykawka concludes…the proposed transplutonian planet has, most likely, escaped from being detected because it moves, apparently, very slowly (below survey sensitivity) or it is currently far from the solar system.
Tempting to imagine a Big Brother watching us from far away…what would be the characteristics of such a planet? An XXL-Pluto? A rocky giant?
This is an hypothesis that has, undoubtfuly, the courage to venture through new territories…let us read what his proponent, while travelling through the history of our solar system, can tell us.
This is quite an astonishing announcement to be digested easily so I asked Lykawka if he could place us, unadvised space exploration followers, in the ground where his proposal gives its steps.
He didn’t say no to the challenge and embarked, taking us, readers, on a journey to his Universe.
(As this Q’n’A was made in my native language, Portuguese, being subsequently translated, I request you, dear reader, to indicate me if you find some error).
According to his explanation the most accepted theory of planetary formation predicts that planets are formed via the accretion of planetesimals, which are the minor objects arising in the first million years of the solar system, and then distributed on a protoplanetary disk (which is, on its own, composed by countless planetesimals).
In the first instants after the formation of the giant planets, these were still immersed in the protoplanetary disk along with the presence of a remaining population of planetesimals, among which were tenths or hundreds of objects with considerable masses (in the order of some 1/10 the mass of the Earth). The last episode of planetary formation it’s, following the astronomer thoughts, the “cleaning” of the regions closer to the orbit of the giant planets.
In other words we might say that planets become so massive that they eject, due to gravitational scattering, the nearby planetesimals.
What does the investigator proposes? Following his theory, one of the mentioned planetesimals with higher mass (let’s say…half Earth’s mass), originally ejected from the region where Uranus and Neptune were formed, disturbed the primordial Kuiper Belt for a period of, approximately, 100 million years and then acquired a inclined, far and stable orbit, what permitted its survival for more than 4 billion years in the outskirts of the solar system.
This massive planetesimal would be, now, at this moment in the history of the Solar System,
orbiting the Sun at a distance of, at least, 100 AU, or, simplifying, 3 to 4 times more distant from our star than Pluto.A far, massive, transplutonian planet in the Lykawka’s description who remarks the importance that the orbital evolution of this planet may be the key to answer several unexplained enigmas of the Kuiper Belt, among which he points out a few…:
The excitation actually observed in the region between 40 and 50 AU is one, another are the populations of different types of objects in the Belt and their orbital characteristics.
Another two pieces of the puzzle can also be put into place under Patryk work: the Belt’s truncated region in the 48 AU region and its small total mass.
The model to be presented by the astronomer at the 39th DPS is, as he tell us, divided in three principal phases regarding the solar system history right after the formation of the giant planets:
We have a first period with an extension of 100 million years where the modelled planet excited and truncated the Kuiper Belt, then, on period II, the giant planets migrated and transported the planet (that I will start naming now for easier identification in the article, as Aernus, the divinity of the Zoelae, an ancient Portuguese tribe located in Trás-os-Montes, the most remote corner of our territory) to an inclined outer orbit through resonant interactions with Neptune (this “age” lasted some hundred million years) and, reaching period III, we find the development of the outer solar system with this planets and the Belt for around more 4 billion years.
Never read something like this? For me it is a première…that is why I asked … if this is the first time a scenario is proposed in this terms, the astronomer puts it like this, in spite of the idea of a planet beyond Pluto being not new (with Planet X leading the parade), this scenario, as presented, is completely new. Our guest states, confidently, that the results obtained by his model invalidate all the previous scenarios based on Planet X’s ideas…and that with an exclamation mark…like this “!”
Returning to more peaceful waters Lykawka tells us that this is the first time that the idea of a planet, being gravitationally exiled from the Uranus-Neptune region and surviving to tell the story, is proposed.
So…where is it? If there were detected other smaller bodies beyond Pluto why was a planet with this mass never detected? Here’s why under spacEurope’s guest view…there are two main reasons being the first the fact of the planet being bright due to its big size and possessing a reasonably reflective surface, but he points out that bright objects in the solar system are rare in the sky…so? To find them we need to observe large areas, this is what is made by wide area surveys.
The detail accuracy that mostly all surveys taken so far possess a limited sensitivity to detect the apparent motion of such objects in the sky (around 1.5arcsec/h).
In his theory, the planet would be, at least, at an average distance of 100 AU, implying motions smaller than the mentioned 1.5arcsec per hour.
The second reason is linked to the planet’s orbital inclination between 20 and 45 degrees.
Why? Under this configuration Aernus would pass close to the solar system plane during only 1-4% of its orbit. As all the surveys made so far studied regions usually close to that level, they had very reduced chances of detecting any planets with more inclined orbits.
Lykawka concludes…the proposed transplutonian planet has, most likely, escaped from being detected because it moves, apparently, very slowly (below survey sensitivity) or it is currently far from the solar system.
Tempting to imagine a Big Brother watching us from far away…what would be the characteristics of such a planet? An XXL-Pluto? A rocky giant?
The astronomer tells us that it would be some sort of Super-Pluto, being formed originally 4.5 billion years ago in the Uranus-Neptune province would be composed mostly by different ices (water, nitrogen, carbon monoxide,methane and other hydrocarbons, which are the most common elements inthe outer solar system) and rocks.
Although it is hard to go for an exact figure, the idea hangs around a planet with the same diameter as the Earth.
And what about its orbit? Its aphelion and perihelion?
My Portuguese-speaker-and writer guest (that was very useful during the questions period, not so quite during the answers translation…) gives its best shot:
The value of the semi-axis (a) would be between 100 and 175 AU and the perihelion (q) would be certainly larger or equal to 80 AU. The planet’s aphelion is more difficult to calculate because it depends of the uncertainties of the previous values, but it can be estimated as being around 120 or even 270 AU.
It is good to remember, as Lykawka states, that none of these figures may be considered exact, he leaves us some examples of possible orbits:
And what about its orbit? Its aphelion and perihelion?
My Portuguese-speaker-and writer guest (that was very useful during the questions period, not so quite during the answers translation…) gives its best shot:
The value of the semi-axis (a) would be between 100 and 175 AU and the perihelion (q) would be certainly larger or equal to 80 AU. The planet’s aphelion is more difficult to calculate because it depends of the uncertainties of the previous values, but it can be estimated as being around 120 or even 270 AU.
It is good to remember, as Lykawka states, that none of these figures may be considered exact, he leaves us some examples of possible orbits:
a = 100 AU, q = 80 AU, Q = 120 AU;
a = 130 AU, q = 80 AU, Q = 180 AU;
a = 175 AU, q = 80 AU, Q = 270 AU.
With the distant orbit and the indicated possible composition Aernus has, probably, no atmosphere. In other words, it would be a frozen world. On the other hand, in the eventual existence of an inner source of energy (radioactive decaying), the possibility of an atmosphere would considerably grow.
And what consequences can derive from the confirmation of the theory in the study of solar systems formation?
The astronomer indicate that one of the major ones would the solidification of the idea that the planetary formation is a process really chaotic, with the ejection of a multitude of planetesimals with varied masses, and the possibility of some of those objects could survive in far orbits.
As giant planets would act as dedicated gardeners cleaning their territory from undesired “specimens”, at a same time a certain parcel of planetesimals would be deposited in much farer distances.
Another consequence would be the fact of solar systems spreading at distances much larger than the usually supposed, where we could observe some planets, which origin lies in gravitational scattering, and their possible resonant interaction with the last ones.
The discovery of a transplutonian planet, as proposed here, would also make us think about the possibility of the existence of other bodies relatively massive and even more distant in our solar system.
Something more? Yes. The mass of Aernus would give us clues about the quantity of mass present in the beggining of the solar system that permitted the formation of this and other planetesimals.
An unavoidable question…what sequence will have this study? Where will future efforts concentrate?
Lykawka believes that studies and theoretical models will have to improve, including, as an example, the orbital evolution of countless massive planetesimals in the process of planetary formation.
He mentions this because, normally, the models just consider the giant planets and disks of smaller objects in the Kuiper Belt and that is not enough to explain the Belt itself.
In the area of observation the surveys might be able to look for objects moving much more slowly, with values inferior to 1.5arcsec/h.
And now, at DPS, what reactions are expected by the ones presenting such proposal? Sincerity is present in his words, he is prepared for two basic reactions, scepticism on one hand and interest in a new perspective in the other… Scepticism because some astronomers have the non existence of a planet beyond Pluto has granted after several decades since the discovery of the last one but, of course, they are not aware of the details that explain why detection have not yet occurred. Although optimism makes it appearance…some might see this model as something really promising, making way for new surveys in order to try to find the supposed planet or even new ideas for the elaboration of new scenarios that will consider the existence of massive planetesimals.
Let us wait for the wave of reactions coming after tomorrow’s presentation…good luck Patryk!
0 comments:
Post a Comment