The Kepler Mission is by far one of the most exciting things NASA has done in recent memory. It’s goal was simple, observe a patch of stars continuously for a long period of time in order to detect the planets that orbit them. It’s lone instrument for doing so is a highly sensitive photometer designed to detect the ever so subtle changes in brightness of a parent star when one of its planets transits in front of it. Whilst the chances are low of everything lining up just right so that we can witness such an event the fact that Kepler could monitor some 145,000 stars at once meant that we were almost guaranteed to see a great deal of success.
Indeed we got just that.
The first six weeks of Kepler’s operation proved to be highly successful with 5 planets discovered, albeit ones that would likely be inhospitable due to their close proximity to their parent stars. The years since then have proved to be equally fruitful with Kepler identifying thousands of potential exoplanet candidates with hundreds of them since being confirmed via other methods. These discoveries have reshaped our idea of what our universe looks like with a planetary system like our own now thought to be a relatively common occurrence. Whilst we’re still a long way from finding our home away from home there’s a ton of tantalizing evidence suggesting that such places are numerous with untold numbers of them right in our own galaxy.
However earlier this year Kepler was struck with an insurmountable problem. You see in order to monitor that field of stars precisely Kepler relied on a set of reaction wheels to ensure it was pointed in the right direction at all times. There are a total of 4 of them on board and Kepler only needed 3 of them in order to keep the precision up at the required level. Unfortunately it had previously had one fail forcing the backup wheel to kick into motion. Whilst that had been running fine for a while on May 15th this year another reaction wheel failed and Kepler was unable to maintain its fix on the star field. At the time this was thought to be the end of the mission and, due to the specialized nature of the hardware, likely the end of Kepler’s useful life.
However, thanks to some incredibly clever mechanics, Kepler may rise again.
Whilst there are only 2 functioning reaction wheels NASA scientists have determined that there’s another source of force for them to use. If they orient Kepler in a certain way so that its solar panels are all evenly lit by the sun (the panels wrap around the outer shell of the craft) there’s a constant and reliable force applied to them. In conjunction with the 2 remaining reaction wheels this is enough to aim it, albeit at a different patch of the sky than originally intended. Additionally it won’t be able to keep itself on point consistently like it did previously, needing to reorient itself every 3 months or so which means it will end up studying a different part of the sky.
Whilst this is a massive deviation from its original intended purpose it could potentially breathe a whole new life into the craft, prolonging its life significantly. Considering the numerous discoveries it has already helped us achieve continuing its mission in any way possible is a huge boon to the science community and a testament to NASA’s engineering prowess. We’re still at the initial stages of verifying whether or not this will work as intended but I’m very confident it will, meaning we’ll be enjoying Kepler aided discoveries for a long time to come.
Mars is by far the most studied planet that isn’t our own, having had 46 separate missions launched to it since the 1960s and is currently host to no less than 5 active missions both in orbit and on its surface. Those missions have taught us a lot about our red celestial sister, the most intriguing of which is that it was once not unlike Earth, covered in vast swaths of ocean which could potentially have been host to all sorts of life. Even more interesting is that while it’s little more than a barren desert that’s only notionally above vacuum it still contains water ice in non-trivial quantities, leading many to speculate that somewhere its liquid form must also exist. The process by which Mars transformed from a lush landscape like ours to the wasteland it is today is still shrouded in mystery and is something that MAVEN, NASA’s latest mission to Mars, is seeking to solve.
MAVEN successfully launched yesterday atop of an ATLAS V rocket and will spend the better part of a year transiting the distance between Earth and Mars. Its primary objective is to investigate the evolution of Mars’ atmosphere to try and ascertain the factors that influenced its demise. Since the current prevailing theory is that a cooling planetary core led to a loss of a protective magnetic field which then allowed the solar wind to slow strip away the atmosphere many of the instruments aboard the craft are geared towards measuring solar particles around Mars’ orbit. The rest of the instrumentation is focused on directly measuring Mars’ atmosphere which will then allow scientists to reconstruct a full picture of it and the influences working on it.
I believe this is also (and someone feel free to correct me on this) the reason for its slightly abnormal orbit for when it arrives at Mars. Instead of taking the usual approach of having a near circular orbit (like the Mars Reconnaissance Orbiter) it instead has a highly elliptical orbit with the closet approach being a mere 150KM above the surface whilst its furthest point is 6200KM out. This would allow the craft to get good measurements of the levels of solar particles as it gets closer to the surface and how that compares to it further out. Considering the orbital period will also only be 4.5 hours it would make for some rather exciting flybys if you were aboard that craft but then again that’s not an orbit you’d use if you had people on board.
The orbit also has the rather unfortunate effect of limiting one of MAVEN’s more long term capabilities: it’s link back to Earth. MAVEN has a 10Mbit/s link thanks to an updated Electra array which is almost twice as powerful as MRO’s. However due to the rather eccentric orbit it won’t be available as often which will limit the amount of data that can be passed back. This doesn’t just impact the satellite itself though as whilst the rovers on Mars can communicate directly to Earth it’s not a very fast connection, so most offload onto a local satellite for their more data hungry applications. Since it’s currently only an augment to the other fleet of satellites around Mars this isn’t too much of an issue although it could present some contention issues later on the track when the other satellites are retired.
The science that MAVEN will conduct on its planned 1 year mission will prove invaluable in determining just what happened to Mars’ atmosphere and, by extension, what the chances are of any life existing on its surface today. It will also provide infrastructure for future missions, allowing them to be more ambitious in the goals that they attempt to reach. For now though it’s 1 day into its long trip to our celestial sister, quietly awaiting the day when it can finally start fulfilling its purpose.
The International Space Station hasn’t really been struggling since the retirement of the Shuttle with it still being able to maintain its full 6 person crew even with the significantly reduced launch capacity. Indeed the bevy of alternative craft that have been visiting the ISS, such as the SpaceX Dragon and the Orbital Sciences Cygnus, have meant that it’s also been well supplied in the absence of a largo cargo tug like the Shuttle. Still there is no current replacement for getting humans up there with that responsibility falling solely to the Russian Soyuz craft although NASA is funding some alternatives. I’ve covered most of them in the past but one of the main contenders, Sierra Nevada Corporation’s Dream Chaser, just passed a significant milestone, albeit with a few issues.
Their craft bears a striking resemblance to the Shuttle, sporting the same thermal tile underside and similar aerodynamic profile. It’s quite a bit smaller than the Shuttle however, being about a quarter of the length and a seventh of the mass, mostly due to its lack of payload bay. It can still carry up a comparable number of astronauts however, up to 7 in its current configuration which is only 1 shy of the Shuttle’s maximum. The design is also quite interesting as whilst it looks like any other space plane it is in fact a lifting body with those wings being on there for control purposes only.
Lifting bodies are an interesting type of craft whereby the craft’s design makes it one giant aerofoil, eliminating the need for big wings in order to generate lift. Indeed NASA has quite a history with lifting body craft having designed and built at least 3 of them in the past. The idea was solid enough for it even to be considered as one of the alternative designs for the Space Shuttle itself although the other requirements (primarily from the Department of Defense) meant that it wasn’t used in the end. Dream Chaser’s design then uses the lifting body for simplicity and efficiency, allowing for their smaller craft to do the one task of ferrying humans into orbit well without any of the additional cruft that plagued the Shuttle.
Dream Chaser recently underwent its first unmanned drop test to confirm its flight characteristics and to give all of its systems their first shakedown. For the most part the mission was a success with the lifting body performing as expected and the remote control systems functioning perfectly. However upon landing the left landing gear failed to deploy causing the craft to spin uncontrollably when the left wing contacted the run way. It’s eerily similar to the landing skid failure that SpaceShipOne encountered during one of its shakedown flights, although that one had a person inside it at the time (he was unscathed, however). It’s not a show stopping issue but it will probably mean furthering testing will be delayed until they can figure out why it happened, and make repairs to their prototype.
For what its worth I think the future of space travel will be in craft like Dream Chaser, ones that favour simplicity and efficiency over trying to make a multi-purpose craft. Indeed all the current contenders in the private space industry are doing just that, building craft with a specific purpose in mind and ensuring they do it efficiently. Whilst this first drop test might have had some hiccups it’s shown that the lifting body idea is aerodynamically sound and that there’s no fundamental flaws in their idea. Once they’ve worked out that landing gear kink I’m sure we’ll see dozens of successful drop tests to follow and, hopefully, some fully powered tests in the not too distant future.
It should come as no surprise that my favourite movie genre is science fiction. Even though I was born long after the original Star Wars trilogy had finished watching it with my parents is still one of the fondest memories I have and that has long since bloomed into a passion for the genre. Of course this also feeds into my love of sciences as whilst I also enjoy fantasy, in all its forms, nothing quite compares to plausible futures that are based on real science. Whilst I understand that scientific accuracy will often take a back seat when the narrative requires it I can’t help but feel compelled to point out some of the more obvious flaws, especially when it’s such a big movie like Gravity.
Now before I launch into this let me just be clear: I absolutely enjoyed Gravity. Whilst I was sceptical about George Clooney and Sandra Bullock being able to bring life to the roles they were given it didn’t take me long to warm to their characters. I was also very surprised by how much tension I felt for multiple different scenes, something which I don’t typically feel, at least not to that extent. All this, combined with the beautiful cinematography culminates in a movie that’s thoroughly enjoyable even if you take the hard line with science like I do. With all that being said though there are some points which bear mentioning and should have you not seen the movie I’ll advise you to skip reading on.
PLOT SPOILERS AHOY
The first thing that I, and several others, have taken issue with is the notion that from the orbit of the Hubble Space Telescope you’d be able see both the International Space Station as well as the Chinese Tiangong station (which is way more developed than current plans indicate, but that’s another story). Even if all of them shared identical orbits, which they don’t, the Hubble is in an orbit that’s some 200KM above the ISS and Tiangong making any naked eye visual impossible. Following on from this the idea that you’d be able to then travel between them becomes somewhat difficult as the energy required to do the plane change manoeuvres would be far above the capabilities of Manned Manoeuvring Unit. Indeed the backup plan NASA had for a shuttle that had suffered a catastrophic failure event such as the one in Gravity was to send another shuttle up there to rescue them, dubbed STS-400, which was the reason why we saw 2 fully fuelled shuttles on their respective launch pads the last time we serviced the Hubble.
I’m sort of able to forgive that for the sake of story however one moment that I won’t was when Bullock is holding onto Clooney’s tether and he says he has to let go or they’ll both be doomed. You see at that particular point there’s no more forces acting on them as once they got tangled up and stopped moving all their momentum had been transferred to the ISS, rendering them at equilibrium. If Bullock had simply tugged on the tether slightly Clooney would have then started drifting lazily towards the ISS and Bullock could have pulled herself back along the parachute cords. I would’ve let that slide if it was a minor side point but it’s one of the main turning points of the movie and unfortunately it just has no basis in reality whatsoever.
One thing I was also going to pan Gravity for was the use of fire extinguishers as thrusters since I figured the amount of delta-v available in them wouldn’t have been enough to provide any meaningful thrust. As it turns out, depending on what kind of extinguisher you have, there could be as much as 100m/s in them, a heck of a lot of thrust by any means. Whilst you’d be far more likely to send yourself into an unrecoverable spin if you were using them in the way shown in Gravity it does lend some credence to the idea of using it to correct your trajectory in order to intercept something else.
PLOT SPOILERS OVER
There were also numerous other minor details but compared to the previous few I mentioned I don’t think they’re worth digging into. Whilst there really were some cringe inducing moments from a science perspective it is a highly enjoyable film, even if you’re not into the whole space scene. It’s also worth it to see it in 3D, something I don’t say often, as the producers have taken care to use 3D as a tool rather than slapping it on in order to increase the ticket price. It might not be super hard sci-fi but then again not many films are and ones of Gravity’s calibre are even rarer.
The Outer Space Treaty dictates that no country will attempt to weaponize space, whether that be through the use of stationing weapons of mass destruction through to using it as an environment to test weapons. To me it’s probably one of the most forward thinking documents to have ever come about with regards to space as it wouldn’t take many in space incidents to make space travel, and by extension any purely scientific endeavours in space, completely infeasible. It also means that space is one of the few places where many nations agree and co-operate freely (although the USA vs China is the one notable exception) as there’s no arms race to be had. Of course space can still be used for military purposes but at least they’re not blowing each other up, further worsening our Kessler Syndrome.
However the Outer Space Treaty doesn’t extend to weapons on a smaller scale, namely firearms or other weapons which could cause grievous bodily harm. I had heard a rumour that Russian space craft had long carried a small firearm along with them as their craft, which typically land on the ground rather than in the sea, had once ended up in a mountain range whereupon the crew was beset by wolves. Personally I didn’t think there was a whole lot of merit to that rumour as the capsules are kind of hard to miss and are easily retrieved by helicopter but apparently the Americans had made similar provisions, except they did not include a firearm. As it turns out the gun in question is quite real and flew in space up until as recently as 2006.
It’s called the TP-82 (pictured above).
On the surface it looks like an overgrown pistol with a long stock attached to the back of it. It’s actually a triple barrelled gun with each of them taking a different type of ammunition. Included in the kit is standard rifle rounds, presumably for taking out those wolves the Russians were so worried about, bird shot (I.E. standard shotgun shells) and flares. The stock was detachable and was actually a machete that had a canvas cover, enabling the returning astronauts and cosmonauts to hack their way through the forest if they happened to land in one. According to many reports it’s something of a decent firearm to use as anyone who’s sent up in a Soyuz capsule is trained in their use, even spaceflight participants.
It seems however that the ammunition for these particular guns has been out of production for quite some time and the remaining reserves have long since expired. Multiple sources I’ve read said that since then the gun has been replaced by a standard Russian army side arm although it seems official sources are rather tight lipped as to whether or not that’s actually the case. Realistically there’s little reason for including them any more anyway so it’s just as likely that they just don’t bother.
The TP-82 is an interesting part of space history both because of the reasons behind its creation and the fact that space is the last place that you’d want to bring a firearm along to. It seems like none of them ever saw any use outside of training missions and many of them ended up as gifts to the commanders of the Soyuz capsules once the mission was over. That’s probably for the best though as I can’t imagine the furore that would be kicked up if one was ever brought out in orbit, let alone if it was used on the ground.
The moon is our closest celestial neighbour and as a consequence is by far one of the most studied celestial bodies. By all accounts it’s a barren wasteland, covered in numerous pot marks from the asteroids that have bombarded it over its lifetime. However the more we investigate it the more we find out that, whilst there’s almost no chance of life being present there, many of the resources that life depends on can be found there. Whilst we’ve known for a while that it would be possible to extract water from the regolith on the surface new observations from NASA’s Moon Mineralogy Mapper instrument aboard India’s Chandrayaan-1 have revealed that there might be actual water on the Moon, just waiting there for us to use.
The initial implications of this are obvious. Water is one of the fundamental resources required for any human based space mission and the amount required usually has to be brought along for the ride. This means the payload capacity used for bringing water along can’t be used for other things, like additional supplies or more equipment, and presents a big challenge for long duration flights. Having a source on the Moon means that any potential bases or colonies established there would have much less reliance on resupply missions from Earth, something which is the primary limiting factor for any off-world colonies that we attempt to establish.
However that pales in comparison when compared to what water on the Moon means for space in general: it’s a primary component for rocket fuel.
Water’s basic composition is hydrogen and oxygen which are the components which power many of the liquid fuelled rocket engines that operate today. Of course in their bonded state they’re not a ready to use propellent exactly so a process is required to break those bonds and get those atoms separated. Thankfully such a process exists, called electrolysis, which splits water down into its component gasses which can then be stored and later used to send rockets on their way. Of course such a process relies on a stable power source which would likely be some like of large solar array backed up by a large battery bank to last through the 2 week long darkness that regularly blankets half the surface.
The biggest challenge that many of the long duration or large payload missions face is the fact that they require more fuel. Carrying more fuel unfortunately also means carry more fuel and there’s points of diminishing returns where you’re spending far too much fuel just to get yourself out of our gravity well. Having a refuelling station or the Moon (or, even better, constructing and launch payloads from there) would mean that we would put larger payloads into space and then push them to the outer reaches of the solar system without having to waste as much fuel to get ourselves out of Earth’s gravitational influence.
Of course seeing this kind of technology implemented is some ways off as it seems like NASA’s next target will be a flag planting mission on Mars. Such technology would be quite applicable to Mars as well seeing as the soil there has a lot of trapped water (and there’s plentiful water ice pretty much everywhere but the equatorial region) but it’d be far more valuable if it was implemented on the moon. In either case I believe this is foundational technology that will be pivotal in humanity pushing itself to the far reaches of our own solar system and, maybe one day, beyond.
There was a long running joke that the International Space Station existed only as a place for the shuttle to go. Whilst that joke ignores the fact that the ISS wasn’t just an American creation it was true that the Shuttle really only had a single destination for the last decade or so of its life. Still it was pretty damn good at its job, both in terms of delivering payloads and its ability to ferry large crews and its retirement left a large hole in launch capabilities that is still yet to be filled. There have been many alternatives popping up however and the second fully privately funded one, the Orbital Sciences Cygnus, made its launch debut last week.
In terms of capabilities the Cygnus is very similar to the Russian Progress craft with the initial versions able to deliver a payload of 2,000kg to the ISS. This is scheduled to be bumped up to 2,700kg after the first 3 vehicles as the craft and its associated launcher will be upgraded, giving it more significantly more interior volume as well. Much like all the other ISS cargo craft it does not have an automated docking capability and needs to be captured by CANADARM2 before being guided to one of the station’s ports. Additionally the Cygnus does not have any capability to reboost the ISS whilst it is docked, something which seems to be uniquely confined to the ATV (although the Progress can do it if required), and does not have any down range capability meaning it burns up on re-entry.
The first Cygnus craft launched late last week after a technical glitch caused a one day delay whilst a fix was developed. The launch itself was trouble free and it spent the weekend catching up to the ISS for a scheduled rendezvous today. Unfortunately whilst the Cygnus was attempting to establish a direct data link with the ISS another glitch was encountered forcing it to abort the current docking attempt. This will delay any further attempts for another couple days due to the orbital mechanics involved but this will give Orbital Sciences enough time to create and test a fix so that the next attempt should be successful.
Just like SpaceX before it Orbital Sciences has a pretty aggressive schedule for successive flights with the next flight lined up for December this year and 3 to follow in 2014. Considering their pedigree with multiple launch systems under their belt this is somewhat expected but it’s still quite amazing to see just how quickly these private companies can move when compared to previous governmental based efforts. It will be interesting to see if they ever adapt the Cygnus to be a human rated craft as whilst they’ve never launched people before they’ve got much of the expertise needed to do so.
It’s great to see that NASA’s COTS program is doing so well, producing results that many believed would be impossible. Whilst they still haven’t bridged the launch capability gap that the Shuttle has left behind they’ve already demonstrated one major part of it and I know it won’t be long before the crewed capability is restored. I’m hopeful that this will enable NASA to continue focusing on the real envelope pushing ideas to further our capabilities in space, leaving the more rudimentary aspects of it to the private market. The future of private space travel is looking brighter by the day and I’m glad Orbital Sciences, with their incredible pedigree of delivering on space projects, has come along for the ride.
Japan’s H-II Transfer Vehicle (HTV) has been quite the little workhorse for the International Space Station, delivering some of the most valuable payloads to the floating space lab to date. I covered its maiden voyage all those years ago praising the craft’s capability to deliver standard payload racks in the absence of the Space Shuttle. Since then it’s gone on to do exactly that with the next 2 flights of the HTV delivering important cargo like Gradient Heating Furnace (used to create large, high quality crystals in microgravity) and the Aquatic Habitat which has allowed astronauts to study how fish live and breed over multiple generations in space. This weekend past saw the HTV launch for the 4th time from Yoshinobu Launch Complex at Tanegashima for a planed 35 day mission to the ISS.
I hadn’t covered any of the subsequent launches of the HTV, mostly because I didn’t find anything particularly interesting to write about them at the time, but looking over them I’m starting to regret my decision. In the 4 years since the HTV’s first launch every iteration of the craft has seen numerous improvements from routine things like improving the communications and avionics packages right through to improving the craft itself to be more lightweight. More interesting still is that JAXA has big plans for future iterations of the HTV, adding in the capability to return cargo to Earth (something that only the Soyuz and SpaceX Dragon are currrently capable of) by 2018 and, impressively, a crewed version that would be very similar to the Soyuz in terms of payload. The more ways we have of getting into space the better and I can’t think of a better craft to use as a base than the HTV for shipping humans up there.
However the HTV’s future isn’t what the space community is all abuzz about with this particular launch, it’s about the curious payload of a little robot called Kirobo. It’s a 34cm tall humanoid robot that’s been designed to communicate with its fellow human astronauts as well as people back on the ground. It’s equipped with voice and face recognition and can recognize emotions of the person its speaking to. It’s essentially designed to further investigate human-robot interactions, something that could prove to be pivotal in long haul flights to our nearest celestial neighbors. The ISS is no stranger to robot visitors either as they’ve been home to Robonaut 2 since early 2011 however it was more geared towards being a telepresence robot that could assist the crew with EVAs that required dexterous movement.
Alongside that plucky little robot companion will be 5.4 tonnes of other cargo for the ISS including support equipment for Kirobo, some cryogenic equipment and spare parts for the ISS itself. Interestingly there will also be 4 CubeSats brought along with it, two of which are ArduSats which are based off the Arduino development boards. Pico Dragon is a Vietnamese creation which will collect space and environment data as well as being a test bed for future satellite communication systems. TechEdSat, which as far as I can tell has no association with the Microsft TechEd brand, is designed to evaluate Space Plug-and-Play Avionics for the San Jose State University. They’re interesting because these usually tag along on other commercial flights and are deployed prior to the main payload although this isn’t the first time the ISS has launched CubeSats for others.
Organisations like JAXA give me a lot of hope for humanity’s space faring future as not only have they delivered a service routinely over the past 4 years they’ve pushed the envelope of their capability each time. The news that we could be seeing crewed vehicles from them within 10 years is incredibly exciting and the HTV will be a welcome addition to the growing family of launch services. They might not be as sexy as SpaceX but they’re doing a service that no one else can do and that’s something that we’ve got to appreciate.
The Proton series of rockets are one of the longest running in the history of spaceflight. They made their debut back in 1965 when the first of them was used to launch the Proton series of scientific satellites which were super high energy cosmic particle detectors. Since then they’ve become the mainstay of the Russian space program being used for pretty much everything from communication satellites to launching the Soyuz and Progress crafts that service the International Space Station. In that time they’ve seen some 384 launches total making it one of the most successful launch platforms to date. However that number also includes 44 full and partial failures, including a few high profile ones that I blogged about a couple years back.
Unfortunately it appears that history has repeated itself today with another Proton crashing in a rather spectacular fashion:
To put this in perspective there’s been about 37 total launches of the Proton rocket since 2010 with 5 of them being either partial or full failures. This isn’t out of line with the current failure rate of the program which hovers around 11% but 4 of those have happened in the last 2 years which is cause for concern. The primary problem seems to be related to the upper stage as 3 of the recent 4 have been due to that failing which can be attributed to it being a revised component that only came into service recently. This particular crash however was not an upper stage failure as it happened long before that component could come online, indicating the problem is with the first stage.
The reasoning behind why this crash ended so spectacularly is pretty interesting as it highlights some of the design differences between the American and Russian designs. Most American launchers have a launch termination system built into them for situations like this, allowing the ground crew to self destruct the rocket mid air should anything like this happen. Russian rockets don’t have such systems and prefer to simply shut down the engines when failures like this happen. However for the safety of the ground crew the engines won’t shut off prior to 42 seconds after launch which is why you see this particular rocket continuously firing right up until it tears itself apart.
Additionally the Russian rockets use a rocket fuel mixture that consists of Unsymmetrical Dimethylhydrazine and Nitrogen Tetroxide. When these two compounds mix together they react in a highly energetic hypergolic reaction, meaning they burn without requiring any ignition source. This is where the giant orange fireball comes from as the aerodynamic stresses on the craft ruptured the fuel and oxidizer tanks, causing them to come into contact and ignite. Other rocket designs usually use liquid oxygen and kerosene which don’t automatically ignite and thus wouldn’t typically produce a fireball like that but the launch termination systems usually ensure that all the remaining fuel is consumed anyway.
Needless to say this doesn’t reflect well on Russia’s launch capabilities but it should be taken in perspective. Whilst the recent failure rate is a cause for concern it has to be noted that the R-7, the rocket that launches both the Progress and Soyuz craft to the ISS, has experienced 0 failures in the same time frame with a very comparable number of launches. It’s quite likely that the failure isn’t part of a larger systemic issue since we’ve had multiple successful launches recently and I’m sure we’ll know the cause sooner rather than later. Hopefully Russia can get the issue resolved before too long and avoid such dramatic incidents in the future.
The idea of planets orbiting other stars doesn’t seem like a particularly novel idea today but it’s only recently that we’ve been able to definitively prove that there are planets outside our own solar system. Whilst there was the beginnings of evidence surfacing back in 1988 the first, definitive proof we had of an extrasolar planet came in 1992, a mere 2 decades ago. As our technology has increased in capability the number of planets we discover year by year has increased dramatically and, even cooler still, the different types of planets we’re discovering is also increasing. Heck we’ve even found planets that don’t have a parent star, something which was almost a fantasy as they were thought to be nearly impossible to detect.
What the last decade has revealed is that planets are not only a common occurrence in the universe but systems like are own, ones with multiple planets in them, are also commonplace. Initially most of the exoplanet discoveries were limited to certain types of planets, namely large gas giants with short orbital periods, but as our technology has improved we’ve been able to discover smaller bodies that orbit further out. Depending on the size of the star and the planet they could end up in what we refer to as the habitable (or Goldilocks) zone, the area where liquid water could exist on the surface. Finding one of these is cause for celebration as that closely matches our own solar system so you can imagine the excitement when we found 3 potentials orbiting Gliese 667C.
Gliese 667C is actually part of a ternary star system which means that each of these planets technically has 3 suns, although the other 2 appear to more like bright stars that have the same illumination capacity as the full moon does here on earth. The diagram above makes it look like there’s potentially 5 planets in the habitable zone (just barely for H and D) but those ones are far more likely to be closer to Venus and Mars respectively. C, F, and E on the other hand are what we call super earths, rocky planets that have a mass around 2 to 10 times that of earth. Typically they’re also quite a bit larger than earth as well which means that the gravity on these kinds of planets is actually quite comparable. Out of all of them Gliese667Cf is the best candidate for habitability and thus extraterrestrial life.
What’s particularly exciting for me is this provides more evidence for the idea that other stars are typically swamped in planets, making the configuration of our solar system quite common. This adds fuel to the already intense discussion that surrounds the Drake Equation which I’d argue has now been tipped towards increasing the left hand side dramatically. Of course you can’t consider that equation without also considering the Fermi Paradox since, as far as we can tell, we’re still all alone out here. The only solution is for us to visit these planets and to see if there is anything there although doing so in an acceptable time frame is still beyond the current limits of our technical ability (but not our theoretical capacity, however).
It’s really quite amusing to see the stuff of science fiction rapidly turn into science fact. As time goes on it seems that the wildest things we could dream of, like planets with multiple suns, are not only real but may not be that unusual either. Hell it’s almost an inevitability that we’ll one day go to places like this just because it’s there. It might not be this century or heck even this millenium but we’ve shown in the past that we’re a stubborn race when it comes to things like this and we’ll be damned if anything will stop us from achieving it. I can only hope medical science advances enough for me to be able to see that and, hopefully, experience such planets for myself.