Project Dragonfly Lives!

Here is another great post from Centauri Dreams, written by Andreas Hein. Good stuff.

2089, 5th April: A blurry image rushes over screens around the world. The image of a coastline, waves crashing into it, inviting for a nice evening walk at dawn. Nobody would have paid special attention, if it were not for one curious feature: Two suns were mounted in the sky, two bright, hellish eyes. The first man-made object had reached another star system.

Is it plausible to assume that we could send a probe to another star within our century? One major challenge is the amount of resources needed for such a mission. [1, 2]. Ships proposed in the past were mostly mammoths, weighing ten-thousands of tons: the fusion-propelled Daedalus probe with 54,000 tonnes and recently the Project Icarus Ghost Ship with over 100,000 tonnes. All these concepts are based on the rocket principle, which means that they have to take their propellant with them to accelerate. This results in a very large ship.

Another problem with fusion propulsion in particular is the problem of scalability. Most fusion propulsion systems get more efficient when they are scaled up. There is also a critical lower threshold for how small you can go. These factors lead to large amounts of needed propellant and large engines, for which you need a large space infrastructure. A Solar System-wide economy is probably needed, as the Project Daedalus report argues [3].

Icarus Ghost Ship

Image: The Project Icarus Ghost Ship: A colossal fusion-propelled interstellar probe

However, there is a different avenue for interstellar travel: going small. If you go small, you need less energy for accelerating the probe and thus less resources. Pioneers of small interstellar missions are Freeman Dyson with his Astrochicken; a living, one kilogram probe, bio-engineered for the space environment [4]. Robert Forward proposed the Starwisp probe in 1985 [5]. A large, ultra-thin sail which rides on a beam of microwaves. Furthermore, Frank Tipler and Ray Kurzweil describe how nano-scale probes could be used for transporting human consciousness to the stars [6, 7].

At the Initiative for Interstellar Studies (I4IS), we wanted to have a fresh look at small interstellar probes, laser sail probes in particular. The last concepts in this area have been developed years ago. How did the situation change in recent years? Are there new, possibly disruptive concepts on the horizon? We think there are. The basic idea is to develop an interstellar mission by combining the following technologies:

  • Laser sail propulsion: The spacecraft rides on a laser beam, which is captured by an extremely thin sail [8].
  • Small spacecraft technology: Highly miniaturized spacecraft components which are used in CubeSat missions
  • Distributed spacecraft: To spread out the payload of a larger spacecraft over several spacecraft, thus, reducing the laser power requirements [9, 10]. The individual spacecraft would then rendezvous at the target star system and collaborate to fulfill their mission objectives. For example, one probe is mainly responsible for communication with the Solar System, another responsible for planetary exploration via distributed sensor networks (smart dust) [11].
  • Magnetic sails: A thin superconducting ring’s magnetic field deflects the hydrogen in the interstellar medium and decelerates the spacecraft [12].
  • Solar power satellites: The laser system shall use space infrastructure which is likely to exist in the next 50 years. Solar power satellites would be temporarily leased to provide the laser system with power to propel the spacecraft.
  • Communication systems with external power supply: A critical factor for small interstellar missions is power supply for the communication system. As small spacecraft cannot provide enough power for communicating over these vast distances. Thus, power has to be supplied externally, either by using laser or microwave power from the Solar System during the trip and solar radiation within the target star system [5].

Size Comparison

Image: Size comparison between an interplanetary solar sail and the Project Icarus Ghost Ship. Interstellar sail-based spacecraft would be much larger. (Courtesy: Adrian Mann and Kelvin Long)

Bringing all these technologies together, it is possible to imagine a mission which could be realized with technologies which are feasible in the next 10 years and could be in place in the next 50 years: A set of solar power satellites are leased for a couple of years for the mission. A laser system with a huge aperture has been put into a suitable orbit to propel the interstellar, as well as future planetary missions. Thus, the infrastructure can be reused for multiple purposes. The interstellar probes are launched one-by-one.

After decades, the probes start to decelerate by magnetic sails. Each spacecraft charges its sails differently. The first spacecraft decelerates slower than the follow-up probes. Ideally, the spacecraft then arrive at the target star system at the same point in time. Then, the probes start exploring the star system autonomously. They reason about exploration strategies, exchange and share data. Once a suitable exploration target has been chosen, dedicated probes descend to the planetary surface, spreading dust-sized sensor networks onto the pristine land. The data from the network is collected by other spacecraft and transferred back to the spacecraft acting as a communication hub. The hub, powered by the light from extrasolar light sends back the data to us. The result could be the scenario described at the beginning of this article.

Artistic impression

Image: Artist’s impression of a laser sail probe with a chip-sized payload. (Courtesy: Adrian Mann)

Of course, one of the caveats of such a mission is its complexity. The spacecraft would have to rendezvous precisely over interstellar distances. Furthermore, there are several challenges with laser sail systems, which have been frequently addressed in the literature, for example beam collimation and control. Nevertheless, such a mission architecture has many advantages compared to existing ones: It could be realized by a space infrastructure we could imagine to exist in the next 50 years. The failure of one or more spacecraft would not be catastrophic, as redundancy could easily be built in by launching two or more identical spacecraft.

The elegance of this mission architecture is that all the infrastructure elements can also be used for other purposes. For example, a laser infrastructure could not only be used for an interstellar mission but interplanetary as well. Further applications include an asteroid defense system [20]. The solar power satellites can be used for providing in-space infrastructure with power [18].

spacecraft swarm

Image: Artist’s impression of a spacecraft swarm arriving at an exosolar system (Courtesy: Adrian Mann)

How about the feasibility of the individual technologies? Recent progress in various areas looks promising:

  • The increased availability of highly sophisticated miniaturized commercial components: smart phones include many components which are needed for a space system, e.g. gyros for attitude determination, a communication system, and a microchip for data-handling. NASA has already flown a couple of “phone-sats”; Satellites which are based on a smart phone [13].
  • Advances in distributed satellite networks: Although a single small satellite only has a limited capability, several satellites which cooperate can replace larger space systems. The concept of Federated Satellite Systems (FSS) is currently explored at the Massachusetts Institute of Technology as well as at the Skolkovo Institute of Technology in Russia [14]. Satellites communicate opportunistically and share data and computing capacity. It is basically a cloud computing environment in space.
  • Increased viability of solar sail missions. A number of recent missions are based on solar sail technology, e.g. the Japanese IKAROS probe, LightSail-1 of the Planetary Society, and NASA’s Sunjammer probe.
  • Greg Matloff recently proposed use of Graphene as a material for solar sails [15]. With an areal density of a fraction of a gram and high thermal resistance, this material would be truly disruptive. Currently existing materials have a much higher areal density; a number crucial for measuring the performance of solar sails.
  • Material sciences has also advanced to a degree where Graphene layers only a few atoms thick can be manufactured [16]. Thus, manufacturing a solar sail based on extremely thin layers of Graphene is not as far away as it seems.
  • Small satellites with a mass of only a few kilograms are increasingly proposed for interplanetary missions. NASA has recently announced the Interplanetary CubeSat Challenge, where teams are invited to develop CubeSat missions to the Moon and even deeper into space (NASA) [17]. Coming advances will thus stretch the capability of CubeSats beyond Low-Earth Orbit.
  • Recent proposals for solar power satellites focus on providing space infrastructure with power instead of Earth infrastructure [18, 19]. The reason is quite simple: Solar power satellites are not competitive to most Earth-based alternatives but they are in space. A recent NASA concept by John Mankins proposed the use of a highly modular tulip-shaped space power satellite, supplying geostationary communication satellites with power.
  • Large space laser systems have been proposed for asteroid defense [20]

In order to explore various mission architectures and encourage participation by a larger group of people, I4IS has recently announced the Project Dragonfly Competition in the context of the Alpha Centauri Prize [21]. We hope that with the help of this competition, we can find unprecedented mission architectures of truly disruptive capability. Once this goal is accomplished, we can concentrate our efforts on developing individual technologies and test them in near-term missions.

If this all works out, this might be the first time in history that there is a realistic possibility to explore a near-by star system within the 21st or early 22nd century with “modest” resources.

I remember when the original Project Icarus study came out in the 1970s and I was absolutely enthralled with it.

At last, interstellar exploration could be possible, not fantasy.

Then the Icarus came out a couple of years ago. The ship was more advanced, but the size doubled. How is that possible in this age of miniaturization?

I think it’s because people love the idea of Battlestar Galactica or U.S.S. Enterprise sized interstellar craft.

You gotta have powerful engines and weapons to cope with angry aliens, right?

Andrea Hein is being smart and paying respect to Robert Foward and Freeman Dyson by writing this study with up to date ideas which encompasses Cube Sat tech and other commercial space company technologies.

Project Dragonfly: The case for small, laser-propelled, distributed probes

Centauri Dreams: To Build the Ultimate Telescope

Paul Gilster posts:

In interstellar terms, a ‘fast’ mission is one that is measured in decades rather than millennia. Say for the sake of argument that we achieve this capability some time within the next 200 years. Can you imagine where we’ll be in terms of telescope technology by that time? It’s an intriguing question, because telescopes capable of not just imaging exoplanets but seeing them in great detail would allow us to choose our destinations wisely even while giving us voluminous data on the myriad worlds we choose not to visit. Will they also reduce our urge to make the trip?

Former NASA administrator Dan Goldin described the effects of a telescope something like this back in 1999 at a meeting of the American Astronomical Society. Although he didn’t have a specific telescope technology in mind, he was sure that by the mid-point of the 21st Century, we would be seeing exoplanets up close, an educational opportunity unlike any ever offered. Goldin’s classroom of this future era is one I’d like to visit, if his description is anywhere near the truth:

“When you look on the walls, you see a dozen maps detailing the features of Earth-like planets orbiting neighboring stars. Schoolchildren can study the geography, oceans, and continents of other planets and imagine their exotic environments, just as we studied the Earth and wondered about exotic sounding places like Banghok and Istanbul … or, in my case growing up in the Bronx, exotic far-away places like Brooklyn.”

Webster Cash, an astronomer whose Aragoscope concept recently won a Phase I award from the NASA Innovative Advanced Concepts program (see ‘Aragoscope’ Offers High Resolution Optics in Space), has also been deeply involved in starshades, in which a large occulter works with a telescope-bearing spacecraft tens of thousands of kilometers away. With the occulter blocking light from the parent star, direct imaging of exoplanets down to Earth size and below becomes possible, allowing us to make spectroscopic analyses of their atmospheres. Pool data from fifty such systems using interferometry and spectacular close-up images may one day be possible.


Image: The basic occulter concept, with telescope trailing the occulter and using it to separate planet light from the light of the parent star. Credit: Webster Cash.

Have a look at Cash’s New Worlds pages at the University of Colorado for more. And imagine what we might do with the ability to look at an exoplanet through a view as close as a hundred kilometers, studying its oceans and continents, its weather systems, the patterns of its vegetation and, who knows, its city lights. Our one limitation would be the orbital inclination of the planet, which would prevent us from mapping every area on the surface, but given the benefits, this seems like a small issue. We would have achieved what Dan Goldin described.

Seth Shostak, whose ideas we looked at yesterday in the context of SETI and political will, has also recently written on what large — maybe I should say ‘extreme’ — telescopes can do for us. In Forget Space Travel: Build This Telescope, which ran in the Huffington Post, Shostak talks about a telescope that could map exoplanets with the same kind of detail you get with Google Earth. To study planets within 100 light years, the instrument would require capabilities that outstrip those of Cash’s cluster of interferometrically communicating space telescopes:

At 100 light-years, something the size of a Honda Accord — which I propose as a standard imaging test object — subtends an angle of a half-trillionth of a second of arc. In case that number doesn’t speak to you, it’s roughly the apparent size of a cell nucleus on Pluto, as viewed from Earth.

You will not be stunned to hear that resolving something that minuscule requires a telescope with a honking size. At ordinary optical wavelengths, “honking” works out to a mirror 100 million miles across. You could nicely fit a reflector that large between the orbits of Mercury and Mars. Big, yes, but it would permit you to examine exoplanets in incredible detail.

Or, of course, you can do what Shostak is really getting at, which is to use interferometry to pool data from thousands of small mirrors in space spread out over 100 million miles, an array of the sort we are already building for radio observations and learning how to improve for optical and infrared work on Earth. Shostak discusses a system like this, which again is conceivable within the time-frame we are talking about for developing an actual interstellar probe, as a way to vanquish what he calls ‘the tyranny of distance.’ And, he adds, ‘You can forget deep space probes.’

I doubt we would do that, however, because we can hope that among the many worlds such a space-based array would reveal to us would be some that fire our imaginations and demand much closer study. The impulse to send robotic if not human crews will doubtless be fired by many of the exotic scenes we will observe. I wouldn’t consider this mammoth space array our only way of interacting with the galaxy, then, but an indispensable adjunct to our expansion into it.

Of course Shostak takes the long, sensor derived view of exploring the Universe, his life’s work is radio telescopes.

Gilster is correct that interferometry will be an adjunct to sending robotic probes to distant interstellar worlds, you can’t make money by just gawking at places.

Or can you? 

Original post.

Centauri Dreams: Creative Constraints and Starflight

I discovered Karl Schroeder’s work when I was researching brown dwarfs some years ago. Who knew that somebody was writing novels about civilizations around these dim objects? Permanence (Tor, 2003) was a real eye-opener, as were the deep-space cultures it described. Schroeder hooked me again with his latest book — he’s dealing with a preoccupation of mine, a human presence in the deep space regions between ourselves and the nearest stars, where resources are abundant and dark worlds move far from any sun. How to maintain such a society and allow it to grow into something like an empire? Karl explains the mechanism below. Science fiction fans, of which there are many on Centauri Dreams, will know Karl as the author of many other novels, including Ventus (2000), Lady of Mazes (2005) and Sun of Suns (2006).

by Karl Schroeder


My newest science fiction novel, Lockstep, has just finished its serialization in Analogmagazine, and Tor Books will have it on the bookshelves March 24. Reactions have been pretty favourable—except that I’ve managed to offend a small but vocal group of my readers. It seems that some people are outraged that I’ve written an SF story in which faster than light travel is impossible.

I did write Lockstep because I understood that it’s not actual starflight that interests most people—it’s the romance of a Star Trek or Star Wars-type interstellar civilization they want. Not the reality, but the fantasy. Even so, I misjudged the, well, the fervor with which some people cling to the belief that the lightspeed limit will just somehow, magically and handwavingly, get engineered around.

This is ironic, because the whole point of Lockstep was to find a way to have that Star Wars-like interstellar civilization in reality and not just fantasy. As an artist, I’m familiar with the power of creative constraint to generate ideas, and for Lockstep I put two constraints on myself: 1) No FTL or unknown science would be allowed in the novel. 2) The novel would contain a full-blown interstellar civilization exactly like those you find in books with FTL.

Creativity under constraint is the best kind of creativity; it’s the kind that really may take us to the stars someday. In this case, by placing such mutually contradictory — even impossible — restrictions on myself, I was forced into a solution that, in hindsight, is obvious. It is simply this: everyone I know of who has thought about interstellar civilization has thought that the big problem to be solved is the problem of speed. The issue, though (as opposed to the problem), is how to travel to an interstellar destination, spend some time there, and return to the same home you left. Near-c travel solves this problem for you, but not for those you left at home. FTL solves the problem for both you and home, but with the caveat that it’s impossible. (Okay, okay, for the outraged among you: as far as we know. To put it more exactly, we can’t prove that FTL is impossible any more than we can prove that Santa Claus doesn’t exist. I’ll concede that.)


Read the rest here…

History H2 Channel: ‘Hangar 1: The UFO Files’ inspires MUFON UFO report

History’s H2 channel release of “Hangar 1: The UFO Files” February 28, 2014, inspired at least one viewer to file a UFO report with the Mutual UFO Network (MUFON), according to testimony in Case 54384 from the MUFON witness reporting database.

The witness had a UFO encounter about 10 a.m. on July 10, 2012, but had kept details of the incident to himself until a few scenes in the “Hangar 1″ show depicted objects that resembled his original sighting. The “Hangar 1″ episodes are based on MUFON case files and the first episode was televised just last evening.

More here…

MUFON: National UFO Alert: Four states report 153 February cases

The National UFO ALERT Rating System has been updated for March 2014, with California, Florida, Texas, and New York moving to a UFO Alert 3 as the highest reporting states with 25 or more cases during the month of February 2014, filed with the Mutual UFO Network (MUFON).

California was the leading high-reporting state in February with 59 cases, down from 102 January cases. Those states in a UFO Alert 4 category with 13 or more reports include: Arizona, Pennsylvania, Michigan, Washington, Georgia, and New Jersey.

More here… Moon Rovers Planned for Commercial Lunar Exploration Project

From the article:

The commercial spaceflight company Golden Spike – which aims fly private missions to the moon by 2020 – has teamed up with the New York-based firm Honeybee Robotics to design robotic rovers for the planned lunar expeditions.

“We’re very proud to be working with Honeybee, which has tremendous experience and a record of successful performance in the development of flight systems for NASA,” Golden Spike President and CEO Alan Stern said in a statement last month.

Golden Spike first announced its goal of launching two-person commercial flights to the moon in December 2012. To boost the scientific output of the expeditions, the company plans to send unmanned rovers to the moon ahead of the crew to collect samples from a wider area than the crew will be able to travel from their landing pad. The rovers will then meet up with the crew’s spacecraft once it arrives, according to the mission plan.  [Golden Spike's Private Moon Mission Plan in Pictures]

“Honeybee brings a unique body of knowledge and skills to help us augment the capabilities of human exploration missions with advanced robotics,” Clive Neal, a researcher at the University of Notre Dame in Indiana and chair of Golden Spike’s lunar science advisory board, said in a statement. “Their participation is a key step forward in helping Golden Spike change the paradigm of human space exploration, through the development of highly capable lunar exploration system architecture for customers around the world.”

Honeybee Robotics has been designing planetary sampling devices for clients including NASA and the US Department of Defense for more than 25 years, and has contributed to the last three of NASA’s Mars landers: The company designed the rock abrasion tool for NASA’s Mars Exploration Rovers Spirit and Opportunity, as well as the icy soil acquisition device (or “Phoenix Scoop”) for the U.S. space agency’s Phoenix Mars lander, and the sample manipulation system and dust removal tool for the Curiosity rover.

Golden Spike officials initially priced the missions at $1.5 billion per person, but has since estimated that the cost could drop down to about $750 million with the help of media coverage and sales of merchandising rights of the missions, Stern told reporters last year at the 29th National Space Symposium in Colorado Spring, Colo. Potential moon flyers include leaders of nations, large corporations, and independently funded individuals.

The companies plan to complete preliminary tests of their rover design by mid-2014.

The cost of the landers and other equipment were the long poles in the tent of NASA’s old Constellation program.

It will be interesting to see if Golden Spike’s plan will work to bring these expenses down. I surely hope so.

Moon Rovers Planned for Commercial Lunar Exploration Project

Spacing Out

Here is a link to December 6, 2013s Youtube video of Jason McClellan’s Spacing Out space/UFO show. Interesting take on science and UFOs.

Scientist wants to teleport Martians to Earth

Craig Venter And Life At The Speed of Light

A U.S. scientist wants to detect Mars life and teleport it to Earth. And he already has the technology to do it.

Dr. J. Craig Venter. (Credit: J. Craig Venter Institute)

Dr. J. Craig Venter. (Credit: J. Craig Venter Institute)

J. Craig Venter, Ph.D. is a leading scientist in the field of genomic research. He is also the founder and CEO of Synthetic Genomics Inc., a privately held company dedicated to “commercializing genomic-driven solutions to address global needs such as new sources of energy, new food and nutritional products, and next generation vaccines.”

He and his research team have been field-testing technology that he believes will revolutionize the search for extraterrestrial life. According to the South China Morning Post, “Not only does Venter say his invention will detect and decode DNA hiding in otherworldly soil or water samples – proving once and for all that we are not alone in the universe – it will also beam the information back to Earth and allow scientists to reconstruct living copies in a biosafety facility.” He hopes to detect Martian life and bring it to Earth using a digital biological converter, or biological teleporter.

The India Times describes, “Dr. Venter’s machine would merely create a copy of an organism from a distant location — more like a biological fax machine.” Storing genetic code in a computer and transmitting it just like any other data is the basic idea.

Cover of J. Craig Venter's latest book. (Credit: Viking Adult)

Cover of J. Craig Venter’s latest book. (Credit: Viking Adult)

Dr. Venter’s team, and scientists from NASA’s Ames Research Center, recently conducted field-testing of this technology in the Mojave Desert south of Baker, California–a dry environment similar to Mars. Researchers tested the unit that would, in theory, send data back from Mars. But according to Dr. Venter, a prototype of the unit that would receive the transmitted data here on Earth exists as well, and will be available for sale next year.

India Times explains that this machine will be able to “automate the synthesis of genes by stringing small pieces of DNA together to make larger ones.” With this technology, “A person with a bacterial infection might be sent the code to recreate a virus intended to kill that specific bacterium.” Venter optimistically surmises that this technology will enable doctors to “send an antibiotic as an email,” and allow diabetics to “download insulin from the Internet.”


The Ultraterrestrials

The Ultraterrestrials

Our perception of subspace beings does not begin and end on our planet or in our plane of existance. It can include those unknown entities, either non-corporeal or of solid matter, that we describe and refer to as alien beings.

On October 30, 1938 the global uneasiness with alien beings began. That was the day Orson Welles narrated his adaptation of H.G. Wells’ novel ‘War of the Worlds’ over the Columbia Broadcasting System radio network. The ‘news bulletin’ style simulation created a panic so widespread that nearly 2 million listeners believed it to be factual. Later in 1947 there would be a reported, later denied, crash of an unknown craft in the New Mexico desert. Then the USAF started ‘Project Blue Book’, a bit of ‘window dressing’ that would possibly ease the public uncertainty as well as coax the Soviets into thinking that U.S. spy planes were actually UFOs. Thousands of sighting reports and science fiction films later, the public fascination with alien beings had been heightened to the point where people are demanding that governments disclose all information in reference to UFOs and the non-human entities that fly these craft.

I may have asked this question more than I would admit but “why do people think that these unidentified flying objects are of such concern?” Theanswers I generally receive are that these may be precursors to an invasion or that the aliens are arriving in small groups in order to gather information before they take over the planet. Most times, I just nod in agreement and change the subject…not that I total disagree with their assessments but more concerned that they aren’t seeing the big picture.

Over the years I have been fortunate to have investigated individuals’ claims of alien entity abduction and infestation. Some of those cases have been documented on my ‘Phantoms & Monsters’ blog, especially when evidence suggested some validity to the claims. In almost all cases the witnesses want to remain anonymous, at least at the initiation of the inquiry. Despite what most people think, I have not met one witness who wanted to cash in on their experience. There may have been some consideration later but that is usually because producers of paranormal television programming hound witnesses until they relent…then the final product is rarely factual. But that’s another story.

The word ‘extraterrestrial’ simply means ‘not of or belonging to Earth.’ In that context, it can be defined as any life form or inanimate object that is not from our planet. In the modern vernacular it is simply understood to represent life forms that do not originate from Earth. So I guess the next question is “have the extraterrestrials ever come to Earth?” I think it’s safe to assume that alien life forms have found their way to Earth but I truly doubt they arrived by space craft. For the most part I agree with much of the ancient astronaut theories until the argument centers around mode of transportation.

Of Orphan Worlds and Interstellar Island Hopping

From Centauri Dreams:

Because of my fascination with exotic venues for astrobiology, I’ve always enjoyed Karl Schroeder’s novels. The Canadian writer explored brown dwarf planets as future venues for human settlement in Permanence (2002), and in his new book Lockstep (soon to be published by Tor, currently being serialized in Analog), Schroeder looks at ‘rogue’ planets, worlds that move through the galaxy without a central star. Imagine crimson worlds baked by cosmic radiation, their surfaces building up, over the aeons, the rust red complex organic molecules called tholins. Or consider gas giants long ago ejected from the system that gave them birth by close encounters with other worlds.

Objects like these and more are surely out there given what we know about gravitational interactions within planetary systems, and they’re probably out there in huge numbers. I’m not going to review how Lockstep uses them just yet — in any case, I haven’t finished the book — but we’ll return to its ingenious solution to time and distance problems in a future post. Right now I just want to mention that one of Schroeder’s characters muses upon ‘a hundred thousand nomad planets for every star in the galaxy.’ Now that’s some serious real estate.

If the number sounds like a novelistic exaggeration, it’s nonetheless drawn from recent work. Schroeder is invoking the work of Louis Strigari (Stanford University), who has studied the possibilities not only of planets ejected from their own systems but those that may form directly from a molecular cloud. The figure of 105 free-floating planetary objects for every main sequence star is from a 2012 paper in Monthly Notices of the Royal Astronomical Society (you can read more about Strigari’s ideas in ‘Island-Hopping’ to the Stars).

Rogue planets would be tricky to find but gravitational microlensing should help us set constraints on their actual numbers, and as we’ll see below, direct imaging has its uses. If rogue worlds are available in such quantities, we can imagine a starfaring culture capable of exploiting their resources. We can even speculate that a thick atmosphere that can trap infrared heat coupled with tectonic or radioactive heat sources from within could sustain elemental forms of life even in the absence of a star. Tens of thousands of objects in nearby interstellar space would obviously be a spur for exploration.

A Newly Found Orphan World

Eighty light years from Earth floats a solitary planet that has been discovered through its heat signature in data collected by the Pan-STARRS 1 wide-field survey telescope on Maui. In mass, color, and energy output, the world is similar to directly imaged planets. As you might expect, PSO J318.5-22, a gas giant about six times the mass of Jupiter, turned up during a search for brown dwarfs, delving into the datasets of a survey that has already produced about 4000 terabytes of information. The discovery was then followed up through multiple observations by equipment on nearby Mauna Kea, with spectra from the NASA Infrared Telescope Facility and the Gemini North Telescope indicating the young, low-mass object was not a brown dwarf.


Image: Multicolor image from the Pan-STARRS1 telescope of the free-floating planet PSO J318.5-22, in the constellation of Capricornus. The planet is extremely cold and faint, about 100 billion times fainter in optical light than the planet Venus. Most of its energy is emitted at infrared wavelengths. The image is 125 arcseconds on a side. Credit: N. Metcalfe & Pan-STARRS 1 Science Consortium.

“We have never before seen an object free-floating in space that that looks like this. It has all the characteristics of young planets found around other stars, but it is drifting out there all alone,” explained team leader Dr. Michael Liu of the Institute for Astronomy at the University of Hawaii at Manoa. “I had often wondered if such solitary objects exist, and now we know they do.”

The find is interesting on a number of levels, not least of which is that observations of gas giant planets around young stars have shown that their spectra differ from those of L- and T-class brown dwarfs. Young planets like these, according to the paper on this work, show redder colors in the near-infrared, fainter absolute magnitudes at the same wavelength and other spectral peculiarities that suggest the line of development between brown dwarfs and gas giant planets may not be as clear cut as once assumed. The paper makes clear how complex the issue is:

PSO J318.5−22 shares a strong physical similarity to the young dusty planets HR 8799bcd and 2MASS J1207−39b, as seen in its colors, absolute magnitudes, spectrum, luminosity, and mass. Most notably, it is the first field L dwarf with near-IR absolute magnitudes as faint as the HR 8799 and 2MASS J1207−39 planets, demonstrating that the very red, faint region of the near-IR color-magnitude diagram is not exclusive to young exoplanets. Its probable membership in the β Pic moving group makes it a new substellar benchmark at young ages and planetary masses.

A landmark indeed, and here the Beta Pictoris moving group, a collection of young stars formed about twelve million years ago, is worth noting. Beta Pictoris itself is known to have a young gas giant planet in orbit around it. The newly detected PSO J318.5−22 is lower still in mass than the Beta Pictoris planet and it is thought to have formed in a different way. The paper goes on:

We find very red, low-gravity L dwarfs have ≈400 K cooler temperatures relative to field objects of comparable spectral type, yet have similar luminosities. Comparing very red L dwarf spectra to each other and to directly imaged planets highlights the challenges of diagnosing physical properties from near-IR spectra.

The beauty of objects like these from an astronomical point of view is that we don’t have to worry about filtering out the overwhelming light of a parent star as we study them. Co-author Niall Deacon (Max Planck Institute for Astronomy) thinks PSO J318.5−22 will “provide a wonderful view into the inner workings of gas-giant planets like Jupiter shortly after their birth.” The discovery also gives us much to think about in terms of future explorations as we contemplate a cosmos in which perhaps vast numbers of planets move in solitary trajectories through the galaxy.

I like the idea of targeting “rogue” planets as potential interstellar missions within the next 100 years. The probes can be smaller and the fuel problem won’t be as bad.

Karl Schroeder isn’t the only author who has used rogue planets as interstellar destinations. The old Space: 1999 television series addressed it as well as Peter Watts Blindsight. Good stuff.

Interstellar Wanderers


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