Our cosmic backyard is still a mostly undiscovered place. Sure we know of all the major planets that share the same orbital plane as us but discoveries like the dwarf planets in the asteroid and kuiper belts are still recent events. Indeed the more we look at the things that are right next door to us the more it leads us to question just how some of these things came to be. It was the strange orbits of a few kuiper belt objects that led to the most recent discovery: the potential existence of a 9th planet orbiting our sun.
Why, I hear you ask, if we have a 9th planet have we not come across it before? Well, if confirmed, the reasons for us not seeing this planet before are simple: it’s just too damn far away. Pluto, which was discovered in 1930, is some 7.4 billion kilometers away from the sun at its closest approach whilst Planet 9 (as it is being called) is 5 times that distance at the same point in its orbit. Since planets don’t produce their own light we can only see them when they reflect light of their parent star and, that far out, our sun is a dim speck that barely illuminates anything. That, coupled with the fact that its orbit is perpendicular to ours, makes detection rather difficult and we’ve only found it now due to the effect it’s having on other kuiper belt objects.
The researchers who made the discovery, Konstantin Batygin and Mike Brown (previously credited with the discovery of a dwarf planet, Sedna), were first intrigued by a group of kuiper belt objects that all shared relatively similar orbital properties. Now due to the sheer number of objects that happen to be in the area it’s likely that this will occur by chance sometimes however they often result in unstable orbits. These objects seemed to be quite happy in their strange orbits however so there either had to be a large body, likely a planet, keeping them in line or some other force was at play. In order to verify this one way or the other a planetary model was developed and then simulated to see what other effects a planet might have.
Their simulations predicted that there should also be other kuiper belt objects with orbits that were perpendicular to Planet 9’s orbit. Looking at the data gathered on the numerous objects that exist within the kuiper belt the researchers found 5 objects that matched the simulation’s predictions, a good indicator that a planet is responsible for both them and the other peculiar orbits. This also helped to confirm some attributes of the planet like it’s potential mass (10 times that of earth) and its likely orbital period (10,000+ years). Interestingly enough this helps to fill in a gap in our solar system’s construction as current models predict the most common type of planet is one of Planet 9’s mass.
The researchers are now looking to directly image the planet in order to confirm that it exists. There’s potential for it to show up in data already collected however that will only work if it was currently close to the sun. If it was further out then time will be required on some of the larger ground based or potentially one of the space based telescopes in order to observe it. Either way direct confirmation is some way off but is surely forthcoming.
When it comes to exoplanets the question that I often hear asked is: why are they all largely the same? The answer lies in the methods that we use for detecting exoplanets, the most successful of which is observing the gravitational pull that planets have on their host stars. This method requires that planets make a full orbit around their parent start in order for us to detect them which means that many go unnoticed, requiring observation times far beyond what we’re currently capable of. However there are new methods which are beginning to bear fruit with one of the most recent discoveries being a planet called 51-Eridani-b.
Unlike most other exoplanets, whose presence is inferred from the data we gather on their parent star, 51-Eridani-b is the smallest exoplanet that we’ve ever imaged directly. Whilst we didn’t get anything like the artist’s impression above it’s still quite an achievement as planets are usually many orders of magnitude dimmer than their parent stars. This makes directly imaging them incredibly difficult however this new method, which has been built into a device called the Gemini Planet Imager, allows us to directly image a certain type of exoplanet. The main advantage of this method is that it does not require a lengthy observation time to produce results although like other methods it also has some limitations.
The Gemini Planet Imager was built for the Gemini South Telescope in Chile, the sister telescope of the more famous Gemini North Telescope in Hawaii. Essentially it’s an extremely high contrast imager, one that’s able to detect a planet that’s one ten millionth as bright as its parent star. Whilst this kind of sensitivity is impressive even it can’t detect Earth-like planets around a star similar to our sun. Instead the planets that we’re likely to detect are young jupiter planets which are still hot from their formation being far more luminous than a planet typically is. This is exactly what 51-Eridani-b is, a fiery young planet that orbits a star that’s about 5 times as bright as our own.
Equally as impressive is the technology behind the Gemini Planet Imager which enables it to directly image planets like this. The first part is a coronagraph, a specially designed interference device which allows us to block out the majority of a parent star’s light. Behind that is a set of adaptive optics, essentially a set of tiny mirrors that can make micro-adjustments in order to counteract atmospheric distortions. It has to do this since, unlike space based telescopes, there’s a lot of turbulent air between us and the things we want to look at. These mirrors, which are deformable at the micro level using MEMS, are able to do this with incredible precision.
With the successful discovery of 51-Eridani-b I’m sure further discoveries won’t be far off. Whilst the Gemini Planet Imager might only be able to discover a certain type of planet it does prove that the technology platform works. This then means that improvements can be made, expanding its capabilities further. I have no doubt that future versions of this technology will be able to directly image smaller and smaller planets, one day culminating in a direct image of an Earth-like planet around a sun-like star. That, dear read, will be a day for the history books and it all began here with 51-Eridani-b.
New scientific discoveries get me excited, they really do. After discovering the awesome Science Daily I found myself losing hours in research papers that show cased everything from new discoveries with great potential to good old fashioned applications of science that were already producing benefits for everyone involved. Of course it gets a whole lot more exciting when that science is being conducted on an entirely different planet so you can imagine my excitement when I heard that Curiosity had discovered something amazing, something that had could have been “history in the making”.
It’s one thing for space and science nuts like me to get excited about these kinds of things, we usually know what to expect and the confirmation of it is what gets us all giddy, but its another thing entirely for the rest of the world to start getting excited about it. You see what started out as a couple posts on my feed reader with a couple scientists on the Curiosity team eventually mutated into dozens and when I saw that Australian TV programs were covering it I knew that it had gotten out of hand. It’s not that this was wholly unexpected, the public interest in Curosity has been the highest I’ve seen since the Spirit and Opportunity first touched down on Mars, but I knew that this fever pitch over the potential ground breaking news would inevitably lead to public disappointment no matter how significant the find was.
To put it in perspective Curiosity has a very distinct set of capabilities, most of them targeted towards imaging and the study of the composition of the things it comes across. Much of the speculation I read about Curiosity’s find centred around the idea that it had detected life in some form or another which would truly be earth shattering news. However Curiosity just isn’t set up to do that in the way most people think it is as its microscopes are simply not capable of imaging microbes directly. The only way it could detect signs of life would be through the on-board laboratory using its mass spectrometer, gas chromatograph and laser spectrometer and even then it would only detect organic compounds (like methane) which is a good, but not certain, indication of life.
Unfortunately whilst the scientists had done their best to try and down play what the result might actually be the damage has been done as the public’s expectations are wildly out of alignment with what it could actually be. It’s annoying as it doesn’t help the image of the greater scientific community when things like this happen and it’s unfortunately become a semi-regular occurrence. I can really blame the scientists for this one, they really are working on a historic mission that will further our understanding of Mars and many other things, but care has to be taken to avoid these kinds of situations in the future. Hopefully the media will also refrain from sensationalising science to the point where the story no longer matches the reality, but I’m not holding my breath on that one.
For what its worth though I’m still looking forward to whatever it is they found out we’re still only in the beginning of Curiosity’s mission, meaning there’s plenty more science to be done and many more discoveries to be had. Whilst they might not be the amazing things that the media might have speculated them to be they will still be exciting for the scientific community and will undoubtedly further our understanding in many different areas. Hopefully this will be the only PR debacle of Curiosity’s mission as I’d hate to have to write a follow up post.
I’m increasingly falling in love with games that push back on the traditional ideas of what constitutes a good game in favour of experimenting with new ideas. Back in the golden era of gaming the only metric that seemed to matter was how long a game lasted for with things like story telling and game mechanics taking a back seat. This was the reason behind Nintendo, and many other games developers, making their games so incredibly difficult as to draw out the game experience over a longer period of time. Sometimes it worked, like in Zelda, and other times you got Battletoads, a game that still haunts me to this day. The Unfinished Swan is another in a long line of exploration/story telling games to be released this year that are the antithesis to those ideals and are, for what its worth, incredibly enjoyable to play.
You play as Monroe, a recent orphan who’s just been relocated to an orphanage. Your mother was an avid painter but she was terrible at finishing her work, leaving behind 300 unfinished canvases at her passing. When you were taken to the orphanage you were told that you could bring one, and only one, of the paintings along with you. Out of all the works you choose your mother’s favourite, the swan that was still left unfinished. One night however you awake to see the swan has disappeared from the canvas and there are swan prints leading up to a door that wasn’t there before. Upon entering you’re transferred to a completely white world and your adventure begins.
The Unfinished Swan’s art style is one of incredible simplicity with your first actual game play experience being thrown into a completely white room with no indication of where you are or what you can do. It was quite a jarring experience as I attempted to run around with no indication of actual movement. When I stumbled on the throw paint button (it’s the L/R buttons) I was greeted with a completely black wall. Moving back I then discovered the game’s main mechanic, your ability to throw paint around. For the first level this is your means of discovery but as the game goes on it morphs from simple discovery to all manner of interesting mechanics.
From a technical standpoint the graphics are quite simple with most things being fairly rudimentary models that aren’t textured. It fits in well with the larger narrative and if I’m honest I’m glad that you don’t spend the entire game lobbing paint everywhere to discover where you should be going as I found myself experiencing forms of snow blindness on more than one occasion. That being said the incredibly bare bones style works exceptionally well, drawing your eyes to details that you’d simply ignore otherwise. I might be a little biased though as I have a thing for black/white contrasts like this but my wife seemed to enjoy it as well.
As I mentioned before the main game mechanic is your ability to lob globs of paint at every surface around you. Initially this is how you find your way around but as you progress the game world will evolve to have proper lighting and shadows at which point your paint changes. The game is, at its heart, an exploration title so lobbing paint at every surface in your reach is usually worth it as you can never be sure when there’s something hidden in plain sight, especially with the lack of colour detail to help you discern when something looks amiss.
One example of this that sticks in my head is when I was walking down a corridor that was lit from the outside so one side was completely illuminated and the other side wasn’t. Since it was semi-long I was doing the usual thing of flinging paint right in front of me just for laughs when I noticed that the resulting spray didn’t look like it should. Turns out there was a corridor on the unlit side that was completely black which, had I not been carelessly painting everything in my path, would have been invisible to me. It wasn’t necessary to finish the game (it was one the ancillary aspects of it) but there are dozens of other examples like that throughout The Unfinished Swan.
The balloon system is the carrot that The Unfinished Swan dangles in front of you to tempt you into exploring every nook and cranny within the game world. The balloons can be used to buy toys in the main menu which help you in various aspects of the game. None of them are required to complete it, indeed I finished it with 33 balloons in my pocket, but some of them would have made things a lot easier. Their locations aren’t always obvious like the dark hallway in a dark corridor example I just gave but you can find a good deal of them by simply looking around and then sometimes taking the semi-creative path to the ultimate solution.
The later stages of the game introduce block construction as another mechanic which is very simplistic but does require a bit of nuance in order to get right. As you can see from the screenshot above I wasn’t particularly neat with my block construction, usually creating one and finding it was too high and then remaking it, and many of the solutions I ended up making worked out of sheer brute force rather than being an eloquent solution to the problem put before me. Still the developers behind The Unfinished Swan understand how to pace their games well and the introduction of new mechanics like this one was always done right at the point where the old one was starting to get tedious.
The story is quite magnificent as well, rating as a great children’s story that has enough subtext for adults to enjoy as well. Whilst its only told in fits and bursts between you finding letters on walls and then lobbing paint balls at them the way that the story ties directly into the environment you’re playing through makes it all the more enthralling. The ending is bitter sweet and satsifying and is something that I can feel myself sharing with others both young and old.
The Unfinished Swan is yet another great example of a game that can eschew complicated game mechanics in favour of a simple idea that’s used to its utmost ability. I came into this expecting a wildly different game since I hadn’t read much about it before plunging in and I was pleasantly surprised with what I got. My only minor complaint is that for a 2 hour game it runs $20 (at least here in Australia) which, while I feel is semi-reasonable for this game, will be a barrier to entry for many who may want to play it. Still for those who love a good story or a game that wouldn’t be out of place with Peter Molyneux’s name on it The Unfinished Swan is definitely worth a look in.
The Unfinished Swan is available on PlayStation 3 right now for $19.99. Total game time was approximately 2 hours with 33 balloons collected overall.
It’s getting close to 2 years ago now that I was waiting in Orlando desperately hoping that I’d get to see the Space Shuttle Discovery launch in person, only to have it ripped away from me. I take solace in the fact that it was one of the longest launch delays in the Shuttle’s long history and whilst I didn’t get to go and see it when it did launch all those months later I did watch the online stream and my heart was renewed. Ever since then I’ve wanted to know what the experience would have been like and today it looks like I got my wish.
An enterprising YouTube user has set out to accomplish just that, and it’s magnificent:
Playing it back on my meagre Logitech speakers was impressive enough so I can only imagine how it will go with a proper sound system. I’ve scared the cat enough today with just the first play through so I’ll probably lay off it for a little bit but suffice to say it’s an impressive recreation of what it would be like to be at a shuttle launch. I certainly got nerd chills listening to it.
It was almost 4 months ago that I woke up in Orlando Florida, eagerly awaiting my trip to the fabled Kennedy Space Center and a day to be filled with all manner of space related fun. It was that same day that I had a dream torn from me, leaving my heart broken and me wanting to get as far away from that place as possible. Reading over the post today brought the whole day flooding back, along with the emotions that came with it. Still despite the pain of a dream not realized I couldn’t pull myself away from Twitter and the NASA TV stream, eagerly devouring each and every little detail of Discovery’s final launch into outer space.
And less than 30 minutes ago STS-133 launched from the Kennedy Space Center launch complex 39A.
Discovery’s final flight has been marred by a multitude of technical problems. The first 2 initial scrubs where due to leaks in the Orbital Maneuvering System which is used to control the space shuttle whilst its in orbit. The system consists of two pods at the rear of the orbiter that have a low thrust engine that uses hypergolic propellant and a leak in these would mean the shuttle would be unable to dock with the International Space Station. The leak was thought to be fixed and the launch was good to go on that faithful day, but Discovery wasn’t going without a fight.
The next launch window was scrubbed due to a problem with the backup main engine controller. Initial diagnostics showed that there was some transient contamination and that a reboot brought everything back into line. However after troubleshooting further, finding nothing wrong again, they did notice an unexpected voltage drop was observed. This lead them to delay the launch for 24 hours in order to find the issue. The next day was delayed due to weather and since I was there on the day I could see why they did. The final day for this launch window saw a hydrogen leak from the main tank that was outside acceptable mission limits, and the mission was scrubbed until today.
The external tank on Discovery had multiple issues. The first was the connector used to vent off excess hydrogen during fueling which was what caused the final delay before Discovery’s final launch. During the investigation into why there was such a substantial leak cracks were discovered in some of the external tanks insulation and upon further inspection it was found that many parts of the external tank had cracks through them. The construction of these particular parts of the external tank was different that from what was used previously and NASA has stated that this contributed to the cracking found in the external tank. Extensive repairs were carried out on the tank and it was only declared flight ready earlier this year. This meant that the turnaround time for Discovery was the longest of any shuttle bar STS-35 at 170 days.
What’s so special about STS-133 however is the sheer amount of payload it will be delivering to the ISS. The first will be the Permanent Multipurpose Module which is a modified version of one of the Multi-Purpose Logistics modules that have flown in many previous shuttle missions. Not only will this deliver almost 8 tons worth of cargo to the space station it will also add a significant amount of livable space to the ISS, rivaling that of the Kibo module. Many future crew missions are dedicated to configuring the PMM and it’s sure to prove valuable to the ISS.
Another interesting bit of cargo that’s making its way to the ISS is Robonaut2, the first humanoid robot ever to visit the station. The idea behind it is that a humanoid robot could be capable of performing many tasks that an astronaut does such as space station maintenance. Initially it will be housed inside the ISS and will undergo strict testing to see how it copes in the harsh environment of space. After a while its capabilities could be expanded and it might not be long before you see Robonaut working along side astronauts on EVAs. This could be quite a boon for the astronauts on the ISS as planning repairs can be quite time consuming and Robonaut could provide a speedy alternative in the event of an emergency.
The last, but certainly not least, bit of Discovery’s final payload is the SpaceX DragonEye sensor. This isn’t the first time that NASA has flown something for SpaceX, having taken the same sensor up on board STS-127 and STS-129, but it is likely to be the last time the sensor is flown before a real Dragon capsule attempts to use it to dock with the space station. The DragonEye sensor is an incredibly sophisticated bit of kit. It provides a 3D image based on LIDAR readings and can determine range and bearing information. The whole system went from concept to implementation in just on 10 months, showing the skill that the SpaceX guys have went it comes to getting things done.
To be honest I was going to put off doing this post for a couple days just because I didn’t want to think about STS-133 anymore than I needed to. But the second I saw that the NASA TV steam was up I couldn’t help but be glued to it for the entire time it was up. Sure I might not be there to see it in person but I’ve finally remembered why I became so enamored with space in the first place: it’s just so damned exciting and inspiring. I may have had my heart broken in the past but when a simple video stream of something I’ve seen dozens of times in the past can erase all that hurt I know that I’m a space nut at heart and I’ll keep coming back to it no matter what.
Humanity, for the longest time, has been aware of planets outside the one that we reside on. Ask anyone today about the planets in our solar system and they’re sure to be able to name at least one other planet but ask them about any outside our solar system and you’re sure to draw a blank look. That’s not their fault however as the discovery of planets outside our solar system (which is by definition, not a planet but an exoplanet) is only recent, dating just over 20 years when the first was discovered in 1988. Since then we’ve discovered well over 500 more planets that exist outside our immediate vicinity and whilst their discovery is great none of them have yet been much like the one we currently call home.
In fact the vast majority of the exoplanets that have been discovered have been massive gas giants orbiting their parent stars at the same distance as Mercury orbits from our sun. This threw scientists initially as back then our current theories on solar system formation didn’t support the notion of large planets forming that close to their parent star. However as time we found more and more examples of such planets, these hot gas giants orbiting at velocities the likes we’d never seen before. The reason behind this is simple, the methods we use to find exoplanets are quite adept at finding these planets and not so much those which we’d consider potential homes.
The method by which the vast majority of exoplanets have been discovered is called the Radial Velocity method. As a planet orbits around its parent star the parent star also moves in tandem, tracing out an elliptical path that’s pinned around the common centre of mass between the two heavenly bodies. As the star does this we can observe changes in the star’s radial velocity, the speed at which the star is moving towards or away from this. Using this data we can then infer the minimum mass, distance and speed required to induce such changes in the planet’s radial velocity which will be the exoplanet itself. This method is prone to finding large planets orbiting close to their parent stars because they will cause larger perturbations in the star’s radial orbit more frequently, allowing us to detect them far more easily.
More recently one of the most productive methods of detecting an exoplanet is the Transit method. This method works by continuously measuring a star’s brightness over a long period of time. When an exoplanet crosses in front of its parent relative to us the star’s apparent brightness drops for the time it is in transit. This of course means that this method is limited to detecting planets and stars whose orbits line up in such a way to cause a transit like this. For earth like exoplanets there’s only a 0.47% chance that such planets will line up just right so we can observe them but thankfully this method can be done on tens of thousands of stars at once, ensuring that we discover at least a few in our search. Exoplanets discovered this way usually require verification by another method before they’re confirmed since there are many things that can cause a dip in a star’s apparent brightness.
There are of course numerous other methods to discover planets outside our solar system but for the most part the vast majority of them have been discovered by one of the two methods mentioned above. For both of them they are heavily skewed towards discovering big planets with short transit times as these produce the most observable effects on their parent stars. Still this does not preclude them from finding exoplanets like earth as shown with the recent discovery of Kepler10-b, a small rocky world in torturous conditions:
The planet, called Kepler-10b, is also the first rocky alien planet to be confirmed by NASA’s Kepler mission using data collected between May 2009 and early January 2010. But, while Kepler-10b is a rocky world, it is not located in the so-called habitable zone – a region in a planetary system where liquid water can potentially exist on the planet’s surface.
“Kepler-10b is the smallest exoplanet discovered to date, and the first unquestionably rocky planet orbiting a star outside our solar system,” said Natalie Batalha, Kepler’s deputy science team leader at NASA’s Ames Research Center in Moffett Field, Calif., at a press conference here at the 217th American Astronomy Society meeting.
Kepler-10b is the smallest transitioning planet to be confirmed to date and shows that it’s possible to discover worlds like our own using current technology. As time goes on and the amount of data increases I’m certain that we’ll eventually find more planets like these, hopefully a bit further out so they’ll be in the habitable zone. The Kepler mission is just a few months shy of its 2 year anniversary with at least another 1.5 years to go and if all goes well it should be returning swaths of data for us for the entire time to come.
I’m always fascinated by the latest discoveries in space even when they’re something like a molten mercury 564 light years away. Our technology is becoming more advanced with every passing day and I know that future missions will end up discovering millions of planets at a time with thousands of potentially life supporting worlds. It’s amazing to think that just 3 decades ago we couldn’t be sure that planets existed outside our solar system and today we know for sure there are more than 500 of them out there.
Ain’t science grand?
I was just about to knock off one of the many RSS feeds I had a massive backlog on when I noticed an article about NASA making a pre-announcement about a press conference they were going to have today. Usually this stuff isn’t front page news but this one had just the right combination of words to send us space nuts (and a good chunk of regular people too) into wild speculation about what NASA might have found. Even more interesting was the fact that one of my friends sent me a rabid SMS directing me to the same article. Something told me that whilst this wouldn’t be your run of the mill NASA press conference there was something big on the horizon, leaving my mind to buzz around all the possibilities.
NASA was not one to disappoint on this occasion.
Researchers at NASA’s Astrobiology Institute have discovered a microbe, native to California’s Mono Lake (a highly inhospitable place), that can survive and thrive by replacing one of the essential building blocks of life with an element that’s highly toxic: arsenic. The bacteria, known as GFAJ-1, was known to be arsenic resistant but researchers took it one step further by depriving the microbes of all phosphorus and flooding their environment with arsenic. The result was that not only did the bacteria survive they thrived, continuing to multiply as if nothing had changed in their environment. Further analysis of the bacteria showed that they had incorporated the arsenic into their DNA where the phosphorus should have been. This throws so many things into question and will change the way we search for alien life out in the universe.
The space and science news sites are abuzz with the implications of the discovery and what it means for the future of astrobiology. The news was so big that it even made the morning news here in Australia something that even the shuttle launches struggle to accomplish. Whilst this announcement isn’t as fantastical as some had hoped for (first contact being amongst them) we’re still at a turning point in our understanding about how life formed here on earth and how it can form elsewhere in the universe.
The discovery is interesting as prior to finding these microbes all life on earth has needed to use 6 building blocks in order to survive: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. Arsenic is just below phosphorus on the periodic table so it shares quite a lot of properties with it and that similarity means it can be substituted into some biological reactions. However arsenic is far more reactive than phosphorous and this means that it is highly toxic to almost every life form on the planet. This bacteria however seems to have developed the ability to use arsenic when it is in a phosphorus poor environment and even has the ability to switch back to phosphorous should it become plentiful again (it actually seems to prefer it).
As with any big discovery this one is not without its critics. Steven Benner, a chemist from the Foundation for Applied Molecular Evolution, makes the point that whilst these bacteria were phosphorus starved there were traces of it available. Enough possibly to sustain these bacteria in the arsenic rich environment. Additionally should these bacteria be incorporating arsenic into their DNA it would be in the form of a arsenate, an ester of arsenic. Such a compound would hydrolyse in water making such arsenate based DNA unstable. He hypothesises that the arsenic is being used in some other fashion, possibly in a way that we do not yet understand. The research is of course continuing and will address these concerns.
We’ve known for a long time that life can develop in places we’d long thought it was impossible to do so but this discovery is something on a whole new level. Showing that a life form, even if it’s a simple one, can replace one of the fundamental building blocks of life with something thought to be toxic means we have to rethink the way in which we look for life here and out in the vastness of space. The prospect of finding life on other planets and moons here in our own solar system just got more possible as our understanding of how life can thrive undergoes a radical paradigm shift. I can’t wait to see how this develops and I’m sure this isn’t the only bacteria out there capable of feats like these. Who knows what kind of alien life we’ll find right here in our own little rock called earth.
Staring up at the night sky is one of the most humbling experiences I’ve ever felt. Each of those tiny points of light is a sun burning furiously in a runaway fusion reaction. By comparison I, a mere human, am no more than a tiny fleck in comparison to one of those stars and barely even an atom when compared to the teaming masses of stars that make up that beautiful nightscape. Even more daunting then is the possibility that each of those twinkling stars plays host to a solar system like our own with dozens of planets just waiting for discovery. Our hunt for these planets has brought us hundreds of large gas giants who by the nature have been very easy to detect. Direct imaging of these planets has been nigh on impossible with the precious few we’ve managed to glimpse being extraordinary examples, rather than the rule. That is set to change, however.
Light, you see, is a funny thing. For centuries scientists pondered over the modelling of it, with the two dominant theories describing it as either as a particle or a wave phenomena. Problem is that light didn’t fit neatly into either of the models, requiring complex modelling in order to fit its behaviour into either the particle or wave category. Today many of the properties of light are now explained thanks to Einstein’s theory of wave-particle duality but for a long time one of the most confounding properties of light was that light can interfere with itself. You’ve probably seen this demonstrated to you back in college via the double slit experiment where you get a pattern of light and dark from a single source of light. At the time I didn’t think much of it past the initial intrigue but my discovery of my passion for space many years later had me thinking about how this might be used.
I had been reading about the hundreds of exoplanet discoveries for a while when I heard of 2M1207b which is thought to be the first directly imaged planet outside our solar system. It’s an exceptional planet being an extremely hot gas giant orbiting a very dim companion star. For systems like our own there would be no chance of seeing any planets from the outside thanks to our extremely bright sun and our relative proximity to it. Still knowing that light had the novel ability to cancel itself out I had wondered if we could say build an apparatus that forced light from a parent star to cancel itself out, letting us peer behind the blazing might to see what lie beneath.
It wasn’t until a few years later when I stumbled across the idea of a StarShade which had been proposed many years previously. In essence it would function as an augmentation to any space based telescope positioning itself perfectly in front of the parent star and reducing its brightness by a whopping 10 billion times. In comparison then the tiny planets which were once outshone would glow bright enough for the telescopes to be able to see them directly, hopefully leading to direct detection of many planets orbiting the star. Unfortunately it appears that this project is now defunct but that doesn’t mean the idea doesn’t live on in other forms.
Most recently an international collaboration of scientists developed a Apodizing Phase Plate coronagraph which is in essence a scaled down version of a starshade that can be installed in current telescopes:
Installed on the European Southern Observatory’s Very Large Telescope, or VLT, atop Paranal Mountain in Chile, the new technology enabled an international team of astronomers to confirm the existence and orbital movement of Beta Pictoris b, a planet about seven to 10 times the mass of Jupiter, around its parent star, Beta Pictoris, 63 light years away.
At the core of the system is a small piece of glass with a highly complex pattern inscribed into its surface. Called an Apodizing Phase Plate, or APP, the device blocks out the starlight in a very defined way, allowing planets to show up in the image whose signals were previously drowned out by the star’s glare.
It’s not just planets that this device helps discover either, it can also help detect distant objects that are hidden behind brighter ones. This enables telescopes to become even more powerful than they once were with minimal modifications. Probably the best part about this is that they’re already using them on the Very Large Telescope in Chile, proving that technology is much more than just a theory.
There’s so much to discover in our universe and it always gets me excited to see these pieces of technology that allow us to pull back the veil and peer ever further into the deepest parts of space. It’s so humbling to know that you’re just a tiny piece of a seemingly infinite universe yet it’s so enthralling that I lose myself for hours just staring up at the night sky. I feel so privileged to be living in a time were our knowledge of this universe is increasing at an ever accelerating rate yet we’re still left wondering at the awesome beauty that’s put before us.
For all the exploration of space we’ve done to date we have still found no evidence of life outside our own biosphere. We’ve found many of the building blocks scattered around our solar system but all our attempts to find even the most simplistic of life forms have been met with failure. Still with the raw ingredients being so common in just our own back yard it follows that there’s a high likelihood that somewhere in the deep blackness of space lies another planet that teams with life like our own. Still with the number of exoplanets only numbering in the hundreds and the technology strongly skewed to finding large gas giants close to their parent stars we had yet to come across another planet that life as we know it could call home. That was until just recently.
An enticing new extrasolar planet found using the Keck Observatory in Hawaii is just three times the mass of Earth and it orbits the parent star squarely in the middle of the star’s “Goldilocks zone,” a potential habitable region where liquid water could exist on the planet‘s surface. If confirmed, this would be the most Earth-like exoplanet yet discovered and the first strong case for a potentially habitable one. The discoverers also say this finding could mean our galaxy may be teeming with prospective habitable planets.
“Our findings offer a very compelling case for a potentially habitable planet,” said Steven Vogt from UC Santa Cruz. “The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common.”
Vogt and his team from the Lick-Carnegie Exoplanet Survey actually found two new planets around the heavily studied red dwarf star Gliese 581, where planets have been found previously. Now with six known planets, Gliese 581 hosts a planetary system most similar to our own. It is located 20 light years away from Earth in the constellation Libra.
Gliese 581 is one of the most studied stars in our sky with no less than 6 exoplanets being discovered orbiting it. It’s a red dwarf star meaning it’s much less bright than our sun and is quite a bit less massive. Still the planets that are orbiting it look very familiar with one of it’s planets being very much like Venus (very close to the sun, probably a planetary hot house) and another quite like Mars (much further out, could potentially have or hosted life). The Gliese 581 system provides evidence that our kind of solar system, one with a diverse range of planets and several habitable candidates, is quite possibly very common. Gliese 581g is exciting because unlike it’s two sister planets it’s right smack bang in the middle of the habitable zone, and with that comes the chance of life.
In this picture Gliese 581 resides right near the bottom with the habitable zone being quite close to the parent star, right up to a mere 10% of the distance from earth to our star. Gliese 581g lies right in the middle of this zone and due to the close proximity this leads to a few interesting characteristics. A year on Gliese 581g is a little over 36 days long which is amazing when you consider Mercury, the closest planet to our star, still takes around 88 days to complete one rotation around our sun. Because of this close proximity to its parent Gliese 581g is also tidally locked to it, forcing the same side of the planet to always face the red dwarf star. Because of this I do not believe that life as we know it could exist on this planet. However that does not mean life could not survive (or even thrive) there.
Our version of life is the only model we’ve got to go on right now since we really haven’t come across anything different. Whilst many forms of life might look completely alien to us they all shared the same basics that enabled other life to thrive on earth. The key to all life as we know it is water as nearly everywhere on earth where there’s some form of water we tend to find life teaming there, even in the most inhospitable conditions. Gliese 581g is big enough that it should be able to hold onto a tenable atmosphere and the temperatures at the surface should be sufficient to support liquid water. However the weather on the surface would be anything but calm as cold wind from the night side of the planet would be constantly blowing thanks to the constant heating of the day side. The terminus boundary between eternal night and day could serve as a habitable strip all across the entire planet, but this is where things get tricky.
The day/night and seasonal cycles of this planet have greatly influenced how life formed on this planet. Gliese 581g would have none of these things with no orbital tilt to speak of to generate the seasons and either constant day or night depending on which side of the planet you were on. This means that any life that evolved there would have to cope with such conditions, eliminating the need for a circadian rhythm and any kind of seasonal behaviour. Since nearly all species of life on earth rely on both these mechanisms for survival the life on Gliese 581g would be wildly different from our own, probably lacking the need for sleep and being almost constantly active. Of course there would be other selection pressures at work here as well, leading to even more alien forms of life.
Is life guaranteed to exist there as so many articles claim? Not in the slightest. There are so many factors that lead up to the development of life that we just can’t be certain one way or another. There are some theories that the Moon played a large part in kick starting life on earth and right now we can’t tell if Gliese 581g even has one. There’s also the real possibility that our new celestial cousin has a thick, acidic atmosphere killing any early stages of life well before they had the chance to adapt. Until we can get more data on the planet anything we say about life there is purely speculative and really it will always be that way until we send a probe there to investigate.
Still Gliese 581g means so much to us for what it symbolises. It shows us that our solar system isn’t unique in the galaxy and gives evidence to support the idea that there are untold numbers of planets that are potentially habitable. We’re on the brink on discovering many, many more of planets like Gliese 581g and each one will give us some insight into the formation of our universe and ultimately life itself. We’re still a long way from being able to explore them for ourselves but I know that one day we mere humans will journey to those stars and revel in their beauty.