Astronomy Topic: Planet 9?

Planet 9: A Theory

Howdy again Blog.

Today we are going to be discussing a theory that explains the unusual orbits of a dozen or so Kuiper Belt Objects (also called Trans-Neptunian Objects).

When I was growing up, there WERE 9 planets, the 9th being Pluto (at that point, it was a smudge). In my lifetime, however, the advancement of telescopes has allowed for many other objects in Pluto’s neighborhood to be discovered (including one larger then Pluto). Astronomers would then come to classify Pluto as a Dwarf Planet, and a part of the Kuiper Belt (a large area filled with icy bodies in distant orbits towards the outskirts of the solar system).

This all seemed well and good for a decade or more, until a whole bunch of KBOs had been identified, and their individual orbits started to be mapped and computed. Advanced software would then make lengthy computations to model the orbits of the objects in the solar system in an effort to study their development and interactivity. That practice of modeling, in and of itself, has been going on for a long time, but the greater the number of actual objects observed, the more “accurate” the simulation becomes.

Albeit, given we don’t understand every little thing about gravity, and interactivity… but we DO get quite a bit of it. We now make space probe flight patterns that exploit the gravity of nearby planets to increase acceleration at a fuel-expense minimum (gravity-assist). It can be said we understand the mechanics of that sort of gravity interactivity fairly well, which leads us to the next point of this progression.

With that in mind, the Astronomers who observed the Kuiper Belt Objects found a few of them that had atypical orbits in contrast to the vast majority of the others. Their orbits all had some common elements though, they were elongated in a similar direction, and had corresponding axial tilts which had clearly been subject to significant gravitational forces at some point. Computers are pretty fucking handy it turns out, and after punching all these orbits into the simulation they asked the computer what could have caused these objects to have the orbits they do.

Initially, I was personally of a mind that it could have been possible that a rogue star had passed through the area nearby our solar system, and the gravity disturbance caused the orbits to be the way they are… but that was also disproven quickly because of the fact that there is no star nearby enough to be a culprit for such a crime. Also, the timeline was wrong, as the orbits of the KBOs had not been perturbed all at once. The passing star theory dies there, as it could not explain several additional observed orbital features, and the axial tilt of these TNOs.

The computer chewed on the data, but gave the Scientists an answer they were not at all expecting. The computation showed a high probability of something large lurking in the deep dark of the outer solar system. This unknown object’s gravity was tugging Kuiper Belt Objects out of their natural orbits. In addition to the projection of a whole new planet, the model also explained a few more unusual KBOs that the Scientists had no previous explanation for.

When the complete data set for all known objects in the Kuiper Belt was combined with the existing model, there were 3 objects that fell into the perpendicular orbits predicted by the simulation. The computer had known these objects were there and why before the scientists did. The data pointed, convincingly, to a big planet somewhere out there. But where?

The software projected that Planet 9 would have an orbit with a perihelion of 200 Astronomical Units and an aphelion of 1,200 AU. Those distances are truly insane, considering our farthest planet, Neptune, is 30 AU away at its longest point (aphelion). Oh, 1 AU is a little over 9 million miles.

Right now, a sky survey done from a space telescope a few years ago did not reveal planet 9 anywhere nearby, which might mean that it’s nearing the distant end of its orbital path (considering it takes a projected 20,000 years to complete 1 orbit of the sun). If it is out there, it is going to be difficult to spot. Another question asked by the scientists was: how big was this thing? Alarmingly, they found the object was AT LEAST 10 times the mass of our planet Earth. So, big. There is a type of planet that scientists have observed in extraterrestrial solar systems, called Super Earths, which are extraordinarily large rocky planets of equivalent mass to the suspected Planet 9.

Theorizing about what sort of planet it might be has, in and of itself, a distinct fork in the logic for existence and formation.

Formation Theory 0: Natural Orbit

The first though was: oh well it must have just formed out there, and we’ll update our models to compensate for that. However, this neglected the severe tilt to the solar plain, as well as the fact that there is not enough material in the outer reaches of the solar system to form a 10 Earth mass planet. This logic train stopped right here, and was abandoned.

Formation Theory 1: Rogue Planet

Since the object has such a severely elliptical orbit, and a 30 degree tilt to the plane of the solar system, there is a possibility the world we now call Planet 9 was a rogue planet. It may have been thrown free of its original parent star eons ago, and was just fortunate enough to pass close enough to the sun to be captured in its current bizarre orbit. There are models that grapple with this possibility, but nothing conclusive.

Formation Theory 2: Flung Giant

If our current model for the size of the accretion disk and the overall substance of the gas cloud that our star formed in is wrong, then maybe there are some processes at work that we do not understand. In extrasolar planetary systems, sometimes large Gas Giants are very close to their stars, in a likely consumption of the inner planets as gravity drew it closer and close as the millennia went by. Possibly?

Now we think about our own solar neighborhood… was its past more violent than we have previously theorized? Astronomers continue to work models that show Planet 9 may have developed as a Gas Giant, and been flung out of the solar system but still captured by the fringes of the sun’s influence. While the variables remain largely unknown, the Gas Giant theory lines up with where something of that mass would have needed to have formed.

Is Planet 9 a mysterious Super Earth caught by the sun’s influence from the emptiness of interstellar space, or a once proud Gas Giant, cast out by gravitational disturbances in the solar system’s formation, exiled to the icy reaches?

Conclusion: The Search

With all the observed evidence and modeling, there is a sense of certainty that Planet 9 is out there, waiting to be found. Now, a “gold rush” of sorts is taking place to scan the furthest reaches of the mysterious planet’s possible orbital path, to try to render the object in photograph and finally verify its existence. Dozens of astronomers are engaged in the search, but the area they need to cover is immense, and the magnitude of Planet 9 is quite dim given how far away it is thought to be.

Now, our society is on the cusp of re-defining how we understand our solar system, and paint a picture of where we might be headed. Albeit, geologic and astronomic time are quite different from human perception, the machinery of the universe runs on math, and it is always calculating the next interaction. There is so much we have yet to fully comprehend, even in the most basic of levels. Our understanding is based on the delicate architecture of guessing, and Planet 9 brings a lot of our theories into collision with reality. Will the planet projected by a computer really be there? Time is the fact that will determine what is out there, if not a planet, than something else very large…

Image credits: Wikipedia

Astronomy Topic: Genesis Here and There

Good day Blog.

 

In this article, we are going to have a detailed discussion on a variety of thoughts pertaining to the developmental potential of life in general, and the chances of a genesis that took place somewhere other than on Earth. The subject matter revealed in the following paragraphs is explored using scientific theory, factual observations and heretical speculation on my part. If you are reading this, then the content below should be absorbed with the intent to stimulate thought, and not conclude or prove. I doubt anyone who reads this blog anymore believes a fucking thing I say anyway.

 

Now, to be clear, the term “genesis” is a tad loaded. One thing both scientific and religious definitions have in common is that the burden of proof does not weigh them down. As of this article, Humans have not been able to duplicate the circumstances in which life first formed. They have even gone down to the level of exploring the interactions between individual proteins and amino acids, yet the actual moment of genesis remains unobserved. So, we have a “before” scene where there is this warm organic goop all hanging out in a tidal pool somewhere on a prehistoric shore, mingling. Then, there’s a gap where something happens to make life possible but no one knows what it is, we will call this section “poof!” Then, the “after” scene is basically the start of the evolutionary process which has led to the diversity we know today. Humans have reverse engineered the shit out of every organism they can find, then they did the same thing to all the dead ones too. Two of three isn’t so bad, right?

 

Therefore, when we talk about life on other planets, we are making a big assumption that the spark of genesis is really there and we just don’t understand it. Because we have this sandwich of knowledge around the missing meat, we can infer what might be possible based on the trajectory of the evidence before and after. Despite the incompleteness of the theory, one can’t fault innovation and imagination simply because of a particularly perplexing missing piece.

 

Having provided that perspective, I’d now like to open your mind to a series of fantastical possibilities. Given what we know for certain, we are able to make very educated inferences about the future based on the facts at hand. That’s why we can have a discussion about genesis and extraterrestrial life, because we are open to understanding the vastness of why and the unexplored reaches of how. To fully immerse oneself in this topic is also to embrace a sense of burgeoning community. If life is more common than simply here on this planet, we will not be alone anymore.

 

Even if we don’t quite understand the exact nature of genesis, we can still open several more theory doors to the chance that the spark of first life might take hold in a variety of chemical mediums, or arise from organic molecular combinations we have not seen in our biology. Maybe even life different in fundamental coded structure from Humans and our (so far) unique DeoxyriboNucleic Acid genetic sequences. That would be quite a scientific revelation indeed, and also joyous in a very relieving way. Think of all the things we could learn from other intelligent life. How that discovery would change humanity is something I’d like to see.

 

Let us now go on a journey through our local solar neighborhood. There are some places, right nearby, where life might be happening or has happened pretty recently. We are investigating most all of these objects with scientific instrumentation. Whether having the right ingredients for life, or being a delivery system of the ingredients for or life itself, there are many places extraterrestrial organisms could already be taking hold.

Mars

The planet has deteriorated far beyond the point in which life was likely flourishing and the environment was habitable. Now, however, it’s a piece of overcooked iron toast. The atmosphere is nearly gone, and the surface has been under relentless assault from solar wind and cosmic background radiation for tens if not hundreds of thousands of years. There is no powerful magnetic field stopping the bombardment, and no way Mars can even feasibly hang on to the Carbon Dioxide it has now. Radiation alone renders the top several feet of the surface saturated by unhelpful charged particles. Almost every single life form on Earth would die is several ways, within a few moments of being exposed to the surface of Mars. That being said, there is a significant measure of difficulty to overcome in theorizing about how life could still be happening there. Since only a tiny fraction of particularly durable organisms and bacteria (maybe something like a Tardigrade [which can repair its own D.N.A.]) from Earth would stand any sort of chance of survival, we have no model for where or what to look for as far as identifying an environment on Mars that enables life rather than tries to kill it.

Human beings on the surface are likely to be the deciding factor in determining whether the red planet has or had life. I believe it will only be proven or not by direct observation and laboratory-level intense scrutiny… something probes and rovers cannot provide. In this Human colonization of Mars imaginary scenario, there are nearly endless chances to explore, sample and test to see if life had ever come to exist on Mars. Once we determine when it had or if it had life, we might then also compare the mechanics of Martian life to our own. If we share the same genetic code, there would be a strong possibility that life as we know it would have originally had one genesis. That is, if after radiocarbon dating the sample, a determination can be made about who was first. Since we share the same genetic code, we can infer that the “genesis” that took place on Earth might have been an invasion and eventual global takeover.

Four billion years ago, as the Earth was mostly a molten slag-ball, Mars may have been teeming with life. It had oceans, protection from solar radiation, and all the conditions plus time life would have needed to develop in some way, and achieve diversity. Maybe at some point during Mars’ prosperity, a piece of the surface could have been blasted out into space during a meteor impact. Within that Martian crust would have been some trapped microbial life, stowed away and frozen into stasis by the vacuum of space. It must have been an organism small and durable enough to survive the journey through Earth’s atmosphere, but once warm and on the surface, life for the Martian organisms began again. This burning thought-wagon postulates that there was only one genesis… the one that happened on Mars billions of years ago. That would make you, so-called Earthling, a 2nd generation Martian colonist.

Recently, NASA has announced the discovery of complex organic molecules in a few places across Gale Crater (which NASA has been exploring for 6 years), and also, that there are seasonal Methane plumes which increase in the Martian summer, and decrease in the winter. The cause is unknown at this time, but potentially an indicator of organic processes taking place in a subsurface capacity (there is a chance this outgassing might be a geologic mechanism of some kind as well). The Curiosity Rover recovered a sample rich with organic molecules, having only drilled 4 inches into the rock it was testing. 4 inches? The radioactive bombardment upon those 4 inches of exposed rock has been extreme to a degree we could not possibly comprehend behind our magnetic field. Yet, the sample they tested was still loaded with some of the most crucial building blocks of life. The European Space Agency’s ExoMars lander will be equipped with a drill that can penetrate 6 FEET below the surface, free of the influence of the irradiated zone. in 2020, there is a real ┬áchance of identifying subsurface microbial life, bringing the final question of whether life is possible on other planets into focus.

Europa & Enceladus

Once the first images of these worlds came in from the Voyager missions, the questions began mounting as to the nature of the Gas Giants and their moons. They have always been a source of fascination, and we made them a priority in our exploration of the outer solar system. Later missions to the two largest planets in the neighborhood revealed many hopeful signs that environments existed, beyond Earth, that might support life.

There are a few mechanical characteristics at work here that help to make theorizing about life in these remote places possible: both of these icy moons are orbiting planets vastly larger than they are (the Gas Giants Jupiter and Saturn, respectively), and they are affected by the potent gravitational attraction of their planetary parents. Both Europa and Enceladus are tugged on consistently with what are known as tidal forces. Jupiter physically pulls Europa’s surface closer to it while the moon rotates on its axis. That deformation creates tectonic friction deep inside the moon, and the small cores are able to stay warm.

The disproportionately strong gravity of their Gas Giant parents provides a continual source of internally driven convection. That heat subsequently  melts large amounts of frozen water ice that comprises the outermost layers of each. Water is one of those things that has certainly been entwined in our evolution, and may be necessary for genesis to take place elsewhere.

Life can persevere even in the most extreme environments, which is why we think it could be happening in the subsurface oceans of Europa and Enceladus. A great example of how this could be possible so far from the sun and under miles of ice comes from the discovery of volcanic “black smoker” vents in the of the oceans of Earth. These remote outcroppings of volcanic heat and minerals have entire ecosystems developed in close proximity to the warmth, cut off from everything around them on the seafloor. Undersea volcanic vent habitats prove that sunlight is not necessary for life, and energy through heat can provide the spark needed to create diverse organisms. If similar conditions are going on right now in the deep oceans of these frozen moons, there could be a plethora of complex life with a starting point at a fissure releasing volcanic heat and nutrients on the seafloor. In the expansive layer of liquid water, where there is heat and organic molecules are mixing around, life has a promising chance to develop if it hasn’t already.

A potential (thus far unfunded) mission to Enceladus would be a prolonged orbital survey which would collect a sample from an erupting geyser, a phenomena recently observed and a chance to sample some of the liquid water underneath the icy exterior. Chemical analysis through observation, as well as direct sampling for organic compounds might answer a great many questions about the potential (or current) habitability of the water trapped between the crust and the core. The Enceladus Life Finder would do, well, pretty much what it says, if ever the project is embraced.

Carbonaceous Asteroids

This one is more about something I personally suspect, but the scientific community has largely not all that excited about. These objects would present evidence in the transfer theory where life can survive in space and through re-entry.

Asteroids of this type, like 101955 Bennu (may collide with our planet at some point this century), are made of a lot of organic matter unlike most other asteroids comprised of Iron and Nickel. The things we think these types of asteroids are made out of pose a lot of questions about the ability, or even possibility of life being able to hitch a ride, travel through the vacuum of space, and survive re-entry through an atmosphere. If genesis did not take place on Earth, we may want to consider the possibility that life was already started somewhere else, and just happened to land on Earth at the right time. Even if there is no way life could have survived on or in it, asteroids like Bennu may have provided the final ingredient needed for genesis to take place in the sludge pools near Earth’s early oceans.

We are going to pay a visit to Bennu this year with the OSIRIS-REx. mission, which is well on its way to intercept later in the fall. It is a two-component mission: most of the probe’s time will be spent in orbit, photographing and analyzing. One of the eventual mission objectives will be to extend a sample gathering arm to recover surface material, then, In 2023, return the sample to Earth for study.

These tiny little fragments of some larger object in the solar system’s early history are valuable relics that may point to when “first” genesis took place… maybe long before Mars, at the very beginning of our celestial formation. Or, they could prove to be loaded with useful organics that without, life may not have even been possible on our planet.

Titan

Okay, so here’s where the imagination and theoretical factors are going to kick in.

Titan is a very strange place in a lot of statistical ways, but similar in a significant, visual way. Titan has a thick atmosphere of Nitrogen, like Earth, but also is so cold that Methane clouds pass by overhead, condense and rain down on the land, and fill seas of liquid Methane and Ethane that cover parts of the planet, much like Earth’s oceans. There are storms, wind, and features that from above, look strikingly similar to surfaces on a planet where weathering and water erosion pervade. Most of the mountains on Titan are made of hard, frozen water ice, trapped in that state on the surface with a frightening daytime temperature of -291 degrees Fahrenheit.

So, what exactly about this place gives rise to life? Where’s the heat? Where is the primordial sludge?

Given there is still a lot to be learned about astrobiology, it is probable to assume that if life is possible beyond the Earth, that it may come to rise in a variety of circumstances, and possibly, in unique ways we have not yet been able to conceive of. Titan is overloaded with useful organic molecules, which is a good start. Is it possible that because all the pieces might have been there for just as long as the Earth has been around (roughly), that some form of life could be gleaning an existence off the limited energy resources available? Unlikely, yes, but not at all inconceivable.

There is also a chance that the internal friction of Saturn’s gravity on Titan has allowed for there to be active geology (hence the lack of craters). It is clearly not an inert ball of frozen Nitrogen and water. Saturn’s pull on Titan allows for Methane to exist in all three stages of matter, and liquid organic molecules are useful when constructing biologic life (as we know it). Whether the heat-energy exists somewhere in a subsurface cavern or deep ocean trench remains to be seen. One can’t simply ignore that the ideal primordial soup may exist somewhere other than Earth, and be a home to life in a way we can’t yet fully understand.

Coming up in the not too distant future, NASA intends to send the Titan Mare Explorer to Titan which will patrol the liquid Methane oceans with a wide variety of above and below surface instrumentation, in search of life that may be hidden there. The mission may also integrate a submarine functionality to explore the deeper places of Titan’s Methane seas.

Kuiper Belt Objects & Long-Period Comets

This one kinda combines our sense of mystery and limited understanding of the contributions to existence provided by this region of the solar system. One of the unanswered questions that seems to be puzzling scientists is: where did all the liquid water on Earth come from? How did we get so much? Some scientists think Comets carried it in from the outer solar system during the Late Heavy Bombardment, but there also a lot of research debunking that. However, it can undoubtedly be true that that material Comets and K.B.Os. are made out of contain a lot of organic material, and water (even if its the wrong kind). While having Long-Period Comets collide with the planet is a bummer, the things they leave behind could have greatly contributed if not been directly responsible for life on Earth in the cooling that occurred in the millennia thereafter.

But is there life clinging to existence in a frozen stasis in the distant fringes of the sun’s influence? Did life come from this place originally, long ago, and make its way in towards the sun as gravity distorted orbits? Is it out there now, hiding, waiting to be found?

The real trouble here is that the objects we are discussing are unimaginably far from us to do much more than observe. New Horizons is going to photograph and spectrograph a few of them, but they will not be landed on or otherwise extensively studied up close. As I write this now, that novel probe is an additional 1 billion miles beyond Pluto, headed for another object. The likelihood of life in these places though is inconceivably small. From what we know about life, energy plays a big role in it getting going. There’s almost no energy out there, in the deep cold. The sun is far away, and not providing enough pull or warmth to think active geologic processes are somehow happening by those means. Life would need to have formed with an astonishingly low energy requirement, and from our current models, that doesn’t make sense. Some have thought in situations of binary systems, like Pluto and Charon, that the significant tidal forces could be the reason we observed so much new surface geology and vastly different landscapes on Pluto. That fact, at least means there’s warmth somewhere, enough to melt the frozen Nitrogen and give Pluto the aura of an atmosphere (and blue skies overhead). The possibility of life is low, and the sliver of imagination is that, just a little tiny sliver.

Sadly, objects located in the extended fringe of the sun’s influence are particularly hard to study up close. Landing something on them seems unlikely, as the E.S.A. discovered in its failed Rosetta ┬álanding. Now, the interstellar object in question for the Rosetta mission landed on a Short-Period Comet that was not that far from us, in contrast to where most of the Comets’ buddies are hanging out. Nevertheless, the idea of studying something so potentially volatile and with low gravity presents all sorts of challenges for future Astronomers to ponder. We did, however, crash a probe into a Comet many years ago, and we have also collected organic molecules from their gaseous tails. We know they are made of stuff we have on Earth, but it is unclear what sort of impact (no pun intended) they had.

As far as missions go, getting out to the Kuiper Belt requires a lot of time, and an insane amount of speed. New Horizons, the mission NASA/JPL that gave us all the information we have on Pluto, essentially did a super high-speed drive by at 36,373 miles an hour. Going into orbit around a K.B.O. is not possible at that speed without a DRAMATIC slowdown… which means the probe had to carry more fuel so it could burn some to enter orbit… fuel is heavy and adds extra weight… more weight will make it take longer to get the spacecraft going fast… you see where this is gong. These K.B.O. missions are streamlined, because getting out there as quickly as possible still takes 10 years. The mechanics of landing (more likely, crashing) something on the surface of a Kuiper Belt Object are brutal, and the obstacles to success abound. Even if the spacecraft just fired off a little scientific projectile type instrument of a form, it is uncertain if the descending probe and the spacecraft could be oriented for communication long enough to recover the observations before it got too far from the transmitter.

I think this region will remain unexplored and not fully understood for generations to come.

Conclusions?

Sadly, I don’t think we can draw any; that’s not what these conversations are about. We read, think and wonder. The engine of the imagination roars for a time, then is quiet. I love to sit back and think about all the fascinating things we don’t know, but are trying to figure out. The observable universe is still, fundamentally, not comprehended. Mechanically, we can’t explain why, just like we can’t explain how genesis happened. As a male, I do like conclusions and things that could be considered “done.” Awe for the world has a lot to do with an appreciation and respect for the unknown, and is also a challenge to the interpretation of ourselves in this world. I don’t pretend to have the answer, but that’s not going to stop me from thinking about what the answer could be. The exercise is in exploration, and I do hope you come back and read some more as we will be ranging all over the spectrum with discussion topics.

Thanks for reading, come back again soon for another exciting and imagination-provoking topic.

Images credit: Wikipedia