The Future of Space: A Space Elevator by 2050?

space_elevatorIn the ongoing effort to ensure humanity has a future offworld, it seems that another major company has thrown its hat into the ring. This time, its the Japanese construction giant Obayashi that’s declared its interest in building a Space Elevator, a feat which it plans to have it up and running by the year 2050. If successful, it would make space travel easier and more accessible, and revolutionize the world economy.

This is just the latest proposal to build an elevator in the coming decades, using both existing and emerging technology. Obayashi’s plan calls for a tether that will reach 96,000 kilometers into space, with robotic cars powered by magnetic linear motors that will carry people and cargo to a newly-built space station. The estimated travel time will take 7 days, and will cost a fraction of what it currently takes to bring people to the ISS using rockets.

space_elevator_liftThe company said the fantasy can now become a reality because of the development of carbon nanotechnology. As Yoji Ishikawa, a research and development manager at Obayashi, explained:

The tensile strength is almost a hundred times stronger than steel cable so it’s possible. Right now we can’t make the cable long enough. We can only make 3-centimetre-long nanotubes but we need much more… we think by 2030 we’ll be able to do it.

Once considered the realm of science fiction, the concept is fast becoming a possibility. A major international study in 2012 concluded the space elevator was feasible, but best achieved with international co-operation. Since that time, Universities all over Japan have been working on the engineering problems, and every year they hold competitions to share their suggestions and learn from each other.

space_elevator3Experts have claimed the space elevator could signal the end of Earth-based rockets which are hugely expensive and dangerous. Compared to space shuttles, which cost about $22,000 per kilogram to take cargo into space, the Space Elevator can do it for around $200. It’s also believed that having one operational could help solve the world’s power problems by delivering huge amounts of solar power. It would also be a boon for space tourism.

Constructing the Space Elevator would allow small rockets to be housed and launched from stations in space without the need for massive amounts of fuel required to break the Earth’s gravitational pull. Obayashi is working on cars that will carry 30 people up the elevator, so it may not be too long before the Moon is the next must-see tourist destination. They are joined by a team at Kanagawa University that have been working on robotic cars or climbers.

graphene_ribbonsAnd one of the greatest issues – the development of a tether that can withstand the weight and tension of stresses of reaching into orbit – may be closer to being solved than previously thought. While the development of carbon nanotubes has certainly been a shot in the arm for those contemplating the space elevator’s tether, this material is not quite strong enough to do the job itself.

Luckily, a team working out of Penn State University have created something that just might. Led by chemistry professor John Badding, the team has created a “diamond nanothread” – a thread composed of carbon atoms that measures one-twenty-thousands the diameter of a single strand of human hair, and which may prove to be the strongest man-made material in the universe.

diamond_nanothreadAt the heart of the thread is a never-before-seen structure resembling the hexagonal rings of bonded carbon atoms that make up diamonds, the hardest known mineral in existence. That makes these nanothreads potentially stronger and more resilient than the most advanced carbon nanotubes, which are similar super-durable and super-light structures composed of rolled up, one atom-thick sheets of carbon called graphene.

Graphene and carbon nanotubes are already ushering in stunning advancements in the fields of electronics, energy storage and even medicine. This new discovery of diamond nanothreads, if they prove to be stronger than existing materials, could accelerate this process even further and revolutionize the development of electronics vehicles, batteries, touchscreens, solar cells, and nanocomposities.

space_elevator2But by far the most ambitious possibility offered is that of a durable cable that could send humans to space without the need of rockets. As John Badding said in a statement:

One of our wildest dreams for the nanomaterials we are developing is that they could be used to make the super-strong, lightweight cables that would make possible the construction of a ‘space elevator’ which so far has existed only as a science-fiction idea,

At this juncture, and given the immense cost and international commitment required to built it, 2050 seems like a reasonable estimate for creating a Space Elevator. However, other groups hope to see this goal become a reality sooner. The  International Academy of Astronautics (IAA) for example, thinks one could be built by 2035 using existing technology. And several assessments indicate that a Lunar Elevator would be far more feasible in the meantime.

Come what may, it is clear that the future of space exploration will require us to think bigger and bolder if we’re going to secure our future as a “space-faring” race. And be sure to check out these videos from Penn State and the Obayashi Corp:

John Badding and the Nanodiamond Thread:


Obayashi and the 2050 Space Elevator:


Sources:
cnet.com
, abc.net.au, science.psu.edu

Powered by the Sun: Breakthrough Solar Cells

solar1In addition to becoming cheaper, and increasing in efficiency and yields, solar cell technology is also growing in terms of innovative design. By going beyond the conventional design of silicon panels and electrical cables, researchers are ensuring that solar technology can go farther. And the latest advances in design are especially far-sighted, aiming to merge solar technology with just about any surface, and even sending it into space.

In the former case, researchers at Michigan State University have created a fully transparent solar concentrator, which could turn any window or sheet of glass – from highrise buildings to the screens on smartphones and tablets – into a photovoltaic solar cell. And whereas other “transparent” solar panels have been designed in the past, this one is the first that truly lives up to the word.

transparent-solar-cellScientifically, a transparent solar panel is something of an oxymoron. Solar cells, specifically the photovoltaic kind, make energy by absorbing photons and converting them into electrons. If a material is transparent, by definition it means that all of the light passes through the medium. This is why previous transparent solar cells have actually only been partially transparent, and usually cast a colorful shadow.

To get around this limitation, the Michigan State researchers use a slightly different technique for gathering sunlight. Instead of trying to create a transparent photovoltaic cell, they used a transparent luminescent solar concentrator (TLSC), which consists of organic salts that absorb specific non-visible wavelengths of ultraviolet and infrared light, which they then luminesce (glow) as another wavelength of infrared light (also non-visible).

https://i0.wp.com/www.extremetech.com/wp-content/uploads/2014/08/transparent-luminescent-solar-concentrator-colorful.jpgThis emitted infrared light is guided to the edge of plastic, where thin strips of conventional photovoltaic solar cell convert it into electricity. Currently, the Michigan TLSC has an efficiency of around 1%, but they think 5% should be possible. On their own, these aren’t huge figures, but on a larger scale — every window in a house or office block — the numbers quickly add up to a significant electrical yield.

Moreover, the researchers are confident that the technology can be scaled all the way from large industrial and commercial applications, down to consumer devices, while remaining “affordable.” So far, one of the larger barriers to large-scale adoption of solar power is the intrusive and ugly nature of solar panels. But if large amounts of solar power can be produced from sheets of glass and plastic, it would go a long way to making the scaling process feasible.

solar_panel_origamiAnother major innovation comes from Brigham Young University, where researchers have been working with NASA’s Jet Propulsion Laboratory to address the challenge of Space-Based Solar Power. For some time, scientists have understood that a solar array in orbit of Earth would be ideally suited for solar power collection, since it would be immune to weather, cloud cover or diurnal cycles (aka. nighttime).

Unfortunately, getting solar cells into space is a bit of a problem. In order to be effective, solar panels need to be thin have a large surface area to soak up more rays. This makes it difficult to transport them into orbit, and requires that they be broken down,and flown up piece by piece, and then assembled once in orbit. Given the cost of mounting a sending a single rocket into orbit, this prospect becomes very costly very fast.

solar_panel_origami1However, the Brigham team came up with a simple and elegant solution to this problem, and found it in the form of origami. By working with complex origami folds, they were able to design a solar array that can shrink down to one-tenth of its original size. Folded up, the device is 2.7 meters (8.9 feet) across and can easily wrap around a spacecraft. Once it reaches space, the array would then unfold to become as wide as 25 meters (82 feet).

Given that solar panels deal with large, flat, thin structures, the origami concept seems like a natural fit. And this is not the first time that it has been used in space equipment design – in the 1990’s, Japanese astrophysicist Koryo Miura created a prototype for another folding solar panel. However, that project was abandoned for various reasons, not the least of which was lack of funding.

space-solar-headTo make the concept work and renew interest in the application, he Brigham team worked with Robert Lang, a world-renowned origami expert who also happens to be a mathematician and engineer and once worked at JPL himself. As Brian Trease, a mechanical engineer at the Jet Propulsion Laboratory, said:

He was trained as a physicist, used to work at JPL, and then got tired of the formal bureaucracy and left to start folding paper. Now he’s a world expert… We see value in going directly to any artist, even if they don’t have his credentials, because they have the thousands of hours or folding and tinkering to realize what can and can’t be done. Anytime you can bring in other disciplines, they just visualize things differently and bring in different solutions to your problems.

The new solar panels could be used to power spacecraft and potentially also on orbiting power stations that could wirelessly send energy to Earth via microwaves. A similar design could also be used on Earth to provide new options for portable solar power in remote locations. The same type of design might also be used in architecture or product design because of its unusual looks and function.

NASA_suntowerAccording to Trease, the Department of Defense has already been in touch with them regarding applications for soldiers in the field:

Soldiers right now might carry around 100 pounds, 15 of those pounds are batteries and fuel. If you can eliminate that, you’ve dramatically reduced their load… It’s different from opening an umbrella, because it can accommodate rigid material. You could do something like a deployable glass chandelier or a table. When it’s deployed, it looks like a flower blooming–it’s got a nice aesthetic to it.

In the next few weeks, Trease will also meet with other experts to consider different potential applications for space equipment, like antennas and reflectors, that could also deploy using origami. And given the rapidly-dropping prices associated with placing objects into orbit, this could prove to be the basis for the dream of Space-Based Solar Power – where all our energy needs are met by solar arrays in orbit that then beam them to Earth.

 

Source: extremetech.com, fastcoexist.com

New Anthology Sample: Arrivals!

http://timedotcom.files.wordpress.com/2014/04/beyond-earth-shuttle.jpg?w=1100Lately, I’ve been getting back to work on the space anthology known as Yuva – and for good reason. Not only has our group been blessed with the arrival of some new blood in recent months, but for many of us (me especially), the inspiration bug has bitten after a long hiatus.

Don’t ask me why, but writing for a different genres can be very temperamental. One minute, you find that all you can write about zombies and apocalyptic scenarios; next minute, its all space ships and futurism. Somebody really needs to put a label on inspiration, one that reads “non-transferable”!

In any case, here is the latest sample from my latest anthology story, “Arrivals”. In this scene, we find one of the main characters (Marcellin Strauss) aboard the ship that will take him and its crew to rendezvous with the Second Migration, a flotilla of ships that are rapidly making their way towards Yuva…

*                    *                    *

The tiny space inside his helmet felt terribly confining. And at the moment, the heads-up display, with all its colored light and constant barrage of information, was not helping. And top of all that, there was the launch clock that was slowly counting down in the lower left corner. At the moment, it was the largest thing in his display field, and impossible to ignore. It’s every tick kept pace with the automated voice coming in from Control, and with the frantic beating of his heart.

Strauss could only breathe and try to remember what he had been told during the past few weeks of crash-course training.

Breath steadily, sit tight, and trust in the instruments.

Not exactly the height of preparation; but at the moment, what else could one do? At this point, the ship pretty much flew itself and all they could do was trust the equipment not to kill them. And considering that Strauss wasn’t even flying the thing, he was left with little to do but wait and try not to panic.

Hartberg’s voice sounded in his ear. “Commencing engine ignition sequence…” He felt a low rumble as the ship’s engine began powering up and preparing to slam hydrogen and anti-hydrogen together in a controlled reaction. “Ignition sequence in five, four, three, two, one…”

They were hit by a hard jolt. Vibrations that were enough to make all the colored lights in his field of view turn into a blurred mess took over. Like everyone else in the cabin, he was thrust into his seat and felt the restraints grab him tighter. And within seconds, they began shooting down the runway.

Hartberg‘s voice spoke again within a few seconds, relaying their progress to Control in an unbelievably calm tone.

“Thrust capacity reaching optimal… acceleration normal… beginning ascent in ten seconds…”

Breath steadily, sit tight… he thought as he continued to be pushed back into the seat.

“Five seconds…”

The runway continued to recede behind them. In the distance, he could see the Great Expanse growing larger as they drew nearer to the coast. And then, he felt the slightest lift as the runway dropped beneath them.

Hartberg‘s reports became faster and closer together now.

“Ascent begun, engine function nominal, orbital velocity in sixty seconds…”
The vibrations subsided a little, so that the readouts in his vision seemed discernible. He could only ascertain so much from them, but the fact that all were in the green was reassuring.

Their acceleration mounted and they continued to climb, and Strauss felt himself being pushed harder back into the seat. It was a funny paradox, how breaking the hold of planet’s gravity meant having to endure additional gravitation stress. It was as if Yuva didn’t want them to leave and was trying to pull them back in.

Trust in the instruments, he told himself. Trust in the pilot.

Up ahead, all he could see now was the deep azure of the sky, the slowly receding clouds, and the faint dots of the distant stars. The engine continued to slam particles together in an ongoing effort to achieve maximum thrust, and his body could feel additional bit of acceleration they achieved.

Beneath the noise of the ship, the voices and the instruments, he could hear a dull moaning. It was coming from him, and growing in intensity. A voice soon sounded in his ear, one of the operators at Control demanding to know his status.

“Control to Eagle One. We’ve got Strauss showing very high levels of epinephrine. Advise on the need for a sedative, over.”

Strauss quickly keyed his comm and replied. “This is Strauss. I’m fine. I’m just fine, over. I’m good, don’t dose me.”

His hurried, panting reply was followed by that of the Captain’s, who was sure to use all the proper comm protocol.

“Control, this is Eagle One Actual. That’s a negative on a sedative, over.”

“Roger that, Eagle One.”

There was a slight pause, during which time Strauss stopped making noise and tried to catch his breath. The Captain came back on and tried to talk him down.

“That’s it, Strauss. Just keep breathing. We’re almost there.”

Strauss heard him and felt somewhat reassured. He kept breathing and kept his eyes ahead, focusing on the distant stars. These were much more calming than all the readouts that continued to frantically tick away, showing their speed, engine pressure, altitude, and anything else that was rapidly changing. In time, the sky began to change color. A flare of orange light flickered through the cabin as their sun’s light hit them for the first time without refraction. And very quickly, the distant stars began to burn much brighter.

That’s when Strauss noticed everything change…

The cabin ceased vibrating, the numbers in his field of view began to drop off, and he no longer felt himself being thrust back into his seat. In fact, he now felt the restraints tugging against him to keep him from floating away.

They had done it. They had broken atmo, and were now floating in high orbit above the planet. Hartberg’s voice came back on the line to announce this.

“Control, this is Eagle One. We have broken atmo. I repeat, we have broken atmo, over.”

There was a pause as Strauss was sure the people at Control were howling out in celebration. Just about everyone in the cabin was doing the same. Meanwhile, he licked his lips and tried to get his heart and breathing under control. He could feel his head beginning to spin as his blood pressure dropped and his adrenals took a break. He also became aware of an incredibly dry feeling in his mouth.

All of this made him painfully aware of how sober he was right now, and how much he wished it weren’t so.

Man I picked a bad time to stop drinking!

News from Space: NASA taking Suggestions on Europa

europa_image_0The Jovian moon of Europa remains a mystery that is just dying to be cracked. Although covered in ice, scientists have long understood that tidal forces caused by its proximity to Jupiter have created a warm interior, one which can sustain warm oceans beneath the surface. In the coming years, NASA wants to fly a mission to this planet so we can finally get a look at what, if anything, is lurking beneath that icy crust.

Perhaps emboldened by the success of the Curiosity Rover and the plans for a manned mission to Mars in 2030, NASA has several possible plans for what a Europa mission might look like. If the budget environment proves hospital, then NASA will likely send a satellite that will perform several orbits of the moon, a series of flybys on it, and scout the surface for science and potential landing sites.

europa_reportTowards this end, they are looking for proposals for science instruments specifically tailored to the task. And within a year’s time, they plan to select 20 from a list of those proposed for the mission. At which point, the selectees will have $25 million to do a more advanced concept study. As John Grunsfeld, associate administrator for NASA’s science mission directorate, stated:

The possibility of life on Europa is a motivating force for scientists and engineers around the world. This solicitation will select instruments which may provide a big leap in our search to answer the question: are we alone in the universe?

The Europa mission is not a guarantee, and it’s unclear just how much money will be allocated to it in the long run. NASA has requested $15 million in fiscal 2015 for the mission, but the mission will naturally be subject to budgetary approvals by Congress. If it passes all obstacles, it would fly sometime in the 2020s, according to information released with the budget earlier this year.

europa-lander-2In April, NASA sent out a request for information to interested potential participants on the mission itself, which it plans to cost less than $1 billion (excluding launch costs). Besides its desire to look for landing sites, NASA said the instruments should also be targeted to meet the National Resource Council’s (NRC) Planetary Decadal Survey’s desires for science on Europa.

In NASA’s words, these are what those objectives are:

  • Characterize the extent of the ocean and its relation to the deeper interior;
  • Characterize the ice shell and any subsurface water, including their heterogeneity, and the nature of surface-ice-ocean exchange;
  • Determine global surface, compositions and chemistry, especially as related to habitability;
  • Understand the formation of surface features, including sites of recent or current activity, identify and characterize candidate sites for future detailed exploration;
  • Understand Europa’s space environment and interaction with the magnetosphere.

JIMO_Europa_Lander_MissionAccording to the agency, any instrument proposal must meet NASA’s landing scout goal or the NRC goals. The instruments must also be highly protected against the harsh radiation, and meet planetary protection requirements to ensure no extraterrestrial life is contaminated with our own. In essence, this means than any instruments must be safeguarded against carrying bacteria that could play havoc with Europan microbes or (do we dare to dream!) more complex organisms.

Solicitations are due by Oct. 17, so if you’ve got an idea and think it might make the cut, consult the following solicitation page and have a look at what NASA is looking for. Personally, I got nothing. But that’s why they don’t pay me the big bucks! No, like most of humanity, I will simply be sitting back and hoping that a mission to Europa happens within my lifetime, and that it uncovers – to quote Arthur C. Clarke’s 201o: Odyssey Two – “something wonderful”…

Source: universetoday.com, nspires.nasaprs.com

Forty-Fifth Anniversary of Apollo 11

Apollo11_launch1Today, July 20th, marks the 45th anniversary of the first step being taken on the Moon. And even though the coming decades may involve astronauts setting foot on Mars or a nearby asteroid, the Moon landing will forever remain one of humanity’s greatest accomplishments. And the many speeches, footage and images associated with the mission remain firmly rooted in public consciousness.

Born during the closing months of the Eisenhower administration as a follow-up to Project Mercury – which successfully put astronauts into orbit – Project Apollo was conceived when spaceflight was still very much in its infancy. However, it was under President Kennedy that the goal of “landing a man on the Moon and returning him safely to the Earth” by the end of the decade truly began.

kennedy_moonspeechAnd though some within NASA were already doing some preliminary planning for a manned mission to the Moon in the late 1950s, there was no hardware that could see the mission fly, no rockets large enough to launch a manned spacecraft all the way to the Moon, and no provisions for managing a program of that magnitude. The men and women who brought the lunar landing to fruition were forced to invent almost everything as they went along.

And in the nine years between President Kennedy promising America the Moon and Neil Armstrong’s small step, NASA developed an unprecedented amount of technology and know-how that continues to shape the way NASA and other space agencies plan and implement missions today. These include the Saturn V multistage rockets, which are currently being refurbished for a manned mission to Mars by 2030.

Apollo_11Launching on from Cape Kennedy on the morning of July 16th, 1969, the mission sent Commander Neil Armstrong, Command Module Pilot Michael Collins and Lunar Module Pilot Edwin “Buzz” Aldrin into an initial Earth-orbit. Then, just two hours and 44 minutes after launch, another engines burn put Apollo 11 into a translunar orbit. Four days later, the Lunar Module touched down and the three men – with Armstrong in the lead – stepped onto the Lunar surface.

And for those looking to participate in the anniversary, there are several ways you can participate. On Twitter, @ReliveApollo11 from the Smithsonian National Air and Space Museum is reliving the highlights from Apollo 11 mission to the Moon in “real time”. Also, @NASAHistory is tweeting images and events from the mission, and journalist Amy Shira Teitel (@astVintageSpace) is tweeting pictures, facts and quotes from the mission, again in “real time”.

apollo11_flag2At 7:39 p.m. PDT (10:39 p.m. EDT), when Armstrong opened began the first spacewalk on the Moon, NASA TV will replay the restored footage of Armstrong and Aldrin’s historic steps on the lunar surface. On Monday, July 21 at 7 a.m. PDT (10 a.m. EDT) NASA TV will be broadcasting live from Kennedy Space Center in Florida, where they will be renaming the center’s Operations and Checkout Building in honor of Armstrong, who passed away in 2012.

The renaming ceremony will include NASA Administrator Charles Bolden, Kennedy Center Director Robert Cabana, Apollo 11′s Collins, Aldrin and astronaut Jim Lovell, who was the mission’s back-up commander. International Space Station NASA astronauts Wiseman and Steve Swanson, who is the current station commander, also will take part in the ceremony from their orbiting laboratory 260 miles above Earth.

Apollo_11_bootprintOn Thursday, July 24 at 3 p.m. PDT (6 p.m. EDT), which is the 45th anniversary of Apollo 11′s return to Earth, the agency will host a panel discussion – called NASA’s Next Giant Leap – from Comic-Con International in San Diego. Moderated by actor Seth Green, the panel includes Aldrin, NASA Planetary Science Division Director Jim Green, JPL systems engineer Bobak Ferdowsi, and NASA astronaut Mike Fincke.

In addition to Aldrin recounting his experiences, Fincke and the other NASA staff are slated to talk about the new Orion space capsule and the Space Launch System rocket – both of which will carry humans on America’s next great adventure in space – and what the future holds for space exploration. These will no doubt include talk of the planned missions to an asteroid, Mars, and quite possibly the construction of a settlement on the Moon.

apollo11_flag1The NASA.gov website will host features, videos, and historic images and audio clips that highlight the Apollo 11 anniversary, as well as the future of human spaceflight. You can find it all by clicking here. And if you don’t have NASA TV on your cable or satellite feeds, you can catch it all online here. Plenty has been happening already, marking the anniversary of the launch and recapturing the mission in “real-time”.

Forty five years later, and Apollo 11 still holds a special place in our collective hears, minds, and culture. One can only hope that the next generation of astronauts prove as equal to the task as those who made the Moon Landing were. And I’m sure that when they do make history, Neil Armstrong (may he rest in peace) will be watching approvingly.

And be sure to check out this video from Spacecraft Films, showing the entire Apollo 11 mission in 100 seconds:


Sources: universetoday.com, motherboard.vice.com, nasa.gov, spacecraftfilms.com

News From Space: ESA Sets Sights on Space Debris

space_debrisIt’s no secret that the orbital space lanes are clogged with debris. In fact, our upper atmosphere is so clogged with the remains of dead satellites, old rockets, and assorted space garbage, that initiatives are being planned to remedy the situation. The ESA, for example, has the Clean Space Initiative; and the e.DeOrbit mission that aims to send debris-hunting satellites into orbit to clean up the mess.

The aim of this mission is to clean up the important polar orbits between altitudes of 800 to 1,000 km (500 to 625 mil) that face the prospect of becoming unusable due to the increasing buildup of space debris. As part of the plan, the ESA is also investigating the possibility of using space harpoons to capture large items, such as derelict satellites and the upper stages of rockets.

https://i1.wp.com/images.gizmag.com/gallery_lrg/space-harpoon.jpgThis is just the latest in a series of possible plans to capture debris. In the past, the ESA has revealed that it was looking at capturing space debris in a net, securing it with clamping mechanisms, or grabbing hold of it using robotic arms. However, the latest possibility calls for using capturing debris with a tethered harpoon, which would pierce the debris with a high-energy impact before reeling it in.

Such an approach would not be practical for smaller debris, but is aimed at reeling in uncontrolled multitonne objects that threaten to fragment when colliding with other objects. These sorts of collisions result in debris clouds that would steadily increase in density due to the Kessler syndrome – a scenario in which the density of orbital debris is high enough that collisions generates more debris, increasing the likelihood of further collisions.

Airbus Defence and Space's preliminary design for a space harpoon system (Image: Airbus De...The ESA says the space harpoon concept has already undergone initial investigations by Airbus Defense and Space in Stevenage – two aerospace developers based in the UK. The preliminary design incorporates a penetrating tip, a crushable cartridge to help embed it in the target satellite structure, and barbs to keep it sticking in so the satellite can then be reeled in.

The initial tests involved shooting a prototype harpoon into a satellite-like material to assess its penetration, the strength of the harpoon and tether as the target is reeled in, and the potential for the target to fragment, which would result in more debris that could threaten the e.DeOrbit satellite. The ESA now plans to follow up these initial tests by building and testing a prototype version of the harpoon and its ejection system.

space_laserThe project will examine the harpoon impact, target piercing and the reeling in of objects using computer models and experiments, ultimately leading up to a full hardware demonstration. The space agency has put out the call for bidders to compete for the project contract, and hopes to be sending a working model into orbit by 2021 to conduct some much-needed housecleaning.

Naturally, there are other proposals being considered for debris-hunting. Between the ESA and NASA, there’s also the EPFL’s CleanSpace One debris hunter, and the Universities Space Research Association anti-collision laser concept. And while these remains still very much in the RandD phase, clearing the space lanes is likely to become a central issue once regular missions are mounted to Mars and the outer Solar System.

Sources: gizmag.com, esa.int

News From Space: Alpha Centauri’s “Superhabitable” World

alpha_centauri_newsScientists and astronomers have learned a great deal about the universe in recent years, thanks to craft like the Kepler space probe and the recently launched Gaian space observatory. As these and other instruments look out into the universe and uncover stars and exoplanets, it not only lets us expand our knowledge of the universe, but gives us a chance to reflect upon the meaning of this thing we call “habitability”.

Basically, our notions of what constitutes a habitable environment are shaped by our own. Since Earth is a life-sustaining environment from which we originated, we tend to think that conditions on another life-giving planet would have to be similar. However, scientists René Heller and John Armstrong contend that there might be a planet even more suitable in this galaxy, and in the neighboring system of Alpha Centauri B.

alpha_centauriBb1For those unfamiliar, Alpha Centauri A/B is a triple star system some 4.3 light years away from Earth, making it the closest star system to Earth. The nice thing about having a hypothetical “superhabitable” planet in this system is that it makes it a lot easier to indulge in a bit of a thought experiment, and will make it that much more easy to observe and examine.

According to the arguments put forward by Heller, of the Department of Physics and Astronomy, McMaster University, Hamilton; and Armstrong, of the Department of Physics, Weber State University in Ogden, this planet may be even more suitable for supporting life than our own. It all comes down to meeting the particulars, and maybe even exceeding them.

habitable_sunsFor example, a habitable planet needs the right kind sun – one that has existed and remained stable for a long time. If the sun in question is too large, then it will have a very short life; and if it’s too small, it might last a long time. But the planet will have to be very close to stay warm and that can cause all sorts of problems, such as a tidally locked planet with one side constantly facing the sun.

Our own sun is a G2-type star, which means it has been alive and stable for roughly 4.6 billion years. However, K-type dwarfs, which are smaller than the Sun, have lives longer than the age of the universe. Alpha Centauri B is specifically a K1V-type star that fits the bill with an estimated age of between 4.85 and 8.9 billion years, and is already known to have an Earth-like planet called Alpha Centauri B b.

alpha_centauriBb2As to the superhabitable planet, assuming it exists, it will be located somewhere between 0.5 and 1.4 astronomical units (46 – 130 million mi, 75 – 209 million km) from Alpha Centauri B. All things being equal, it will have a circular orbit 1. 85 AU (276 million km / 172 million miles) away, which would place it in the middle of the star’s habitable zone.

Also, for a planet to sustain life it has to be geologically active, meaning it has to have a rotating molten core to generate a magnetic field to ward off cosmic radiation and protect the atmosphere from being stripped away by solar winds. A slightly more massive planet with more gravity means more tectonic activity, so a better magnetic field and a more stable climate.

 

PlutoHowever, the most striking difference between the superhabitable world and Earth would be that the former would lack our continents and deep oceans – both of which can be hostile to life. Instead, Heller and Armstrong see a world with less water than ours, which would help to avoid both a runaway greenhouse effect and a snowball planet that an overabundance of water can trigger.

Our superhabitable planet might not even be in the habitable zone. It could be a moon of some giant planet further away. Jupiter’s moon Io is a volcanic hellhole due to tidal heating, but a larger moon that Heller and Armstrong call a “Super Europa” in the right orbit around a gas giant could heat enough to support life even if it’s technically outside the star’s habitable zone.

 

alien-worldAccording to Heller and Armstrong, this world would look significantly different from our own. It would be an older world, larger and more rugged, and would provide more places for life to exist. What water there was would be evenly scattered across the surface in the form of lakes and small, shallow seas. And, it would also be slightly more massive, which would mean more gravity.

This way, the shallow waters would hold much larger populations of more diverse life than is found on Earth, while the temperatures would be more moderated. However, it would be a warmer world than Earth, which also makes for more diversity and potentially more oxygen, which the higher gravity would help with by allowing the planet to better retain its atmosphere.

panspermia1Another point made by Heller and Armstrong is that there may be more than one habitable planet in the Alpha Centauri B system. Cosmic bombardments early in the history of the Solar System is how the Earth got its water and minerals. If life had already emerged on one planet in the early history of the Alpha Centauri B system, then the bombardment might have spread it to other worlds.

But of course, this is all theoretical. Such a planet may or may not exist, and may or may not have triggered the emergence of life on other worlds within the system. But what is exciting about it is just how plausible its existence may prove to be, and how easy it will be to verify once we can get some space probes between here and there.

Just imagine the sheer awesomeness of being able to see it, the images of a super-sized Earth-moon beamed back across light years, letting us know that there is indeed life on worlds besides our own. Now imagine being able to study that life and learning that our conceptions of this too have been limited. What a time that will be! I hope we all live to see it…

 

 

Sources: gizmag.com, universetoday.com