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Quantifying KIC 8462852 Power Beaming

Plasma physicist James Benford, CEO of Microwave Sciences, is well known here on Centauri Dreams. Today he is joined by his son Dominic, whose work focuses on the development of ultrasensitive technologies for far-infrared through millimeter-wave astronomy. The younger Dr. Benford is Program Scientist for NASA’s WFIRST mission, which is designed to conduct major surveys in the near-infrared to answer fundamental questions on the nature of dark energy, the distribution of dark matter, the occurrence of planets around other stars, and even to enable the direct imaging of planetary systems. Previously, Dominic was Chief Scientist for the Cosmic Origins Program Office, as well as Deputy Mission Scientist for WISE, the Wide-field Infrared Survey Explorer. In today’s entry, the Benfords look at the SETI Institute’s recent observations of KIC 8462852 and analyze the detectability of power beaming at these distances.

by James and Dominic Benford

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The recent report from the SETI Institute of radio observations of the anomalous star KIC 8462852 has immediate implications. That report concluded that, using the Allen Array, no narrowband radio signals were found above a few hundred Janskys in 1 Hz channels and no “wideband” signals above 100 Janskys are seen in 100 kHz channels. This is for observations taking place for 2 weeks, observing half the time. This implies about 180 hours of observations, although only about 1% of the time is spent at any individual frequency.

The purpose of the observations is to see whether the anomalous star is the site of a super-civilization that might be incidentally radiating sufficient power that we can observe, i.e., leakage radiation. They might even be intentionally producing signals for us to detect. The easiest way to do that is to ‘piggyback’, to put a message onto the power beams.

The thresholds they have reported, above which no signals are present, have implications for the presence of power beams in the anomalous star system. Beaming power on astronomical scales has been a frequent topic on this site and it has long been pointed out that the beaming of power for various purposes could be observable at astronomical distances.

The missions suggested for power beaming involve Earth–to–space applications such as launching spacecraft to orbit or raising satellites from a lower orbit to a higher one. Several workers have studied interplanetary missions, meaning space–to–space transfers of cargo. Finally, launch into the outer solar system and for interstellar precursors and ultimately for starships has also been quantified.

We have examined the thresholds in light of concepts proposed for beaming power in and around our solar system. By comparing the reported thresholds set by the SETI Institute, the non-observation of leakage signals at their stated thresholds implies the following:

  • Orbit raising missions, which require lower power, are not detectable at the thresholds of the Allen Array.
  • Launch from a planetary surface into orbits would be bright enough to be seen by the 100 kHz observations. However, the narrow bandwidth 1 Hz survey would not see them.
  • Interplanetary transfers by beam-driven sails should be detectable in their observations, but are not seen. This is for both the narrow 1 Hz and for the “wideband” 100 kHz observations.
  • Starships launched by power beams with beamwidths that we happen to fall within would be detectable, but are not seen.

These results must be qualified by noting:

  • Power beaming is not an isotropic endeavor, and so the geometry of the transmitter and the intended recipient will produce a conjunction from our point of view only episodically. The observations were conducted for only a limited time and further observations would provide a more stringent constraint.
  • Even the “wideband” observation is actually quite narrow compared with the kinds of sources that would be used in power beams, based on our current understanding of microwave physics. For the applications discussed here, the 100 kHz bandwidth observed would be about 10 to 100 millionths of the center frequency of the Beamer. But high-power devices are inherently not designed for such narrow bandwidths.
  • The frequencies we would use for power beaming are in the millimeter band, so are outside the microwave range the Allen Array observed.

Therefore the observations by the Allen Array are not sufficiently broad to produce firm conclusions about realistic Beamers.

Readers are encouraged to consult the original paper: Harp et al., “Radio SETI Observations of the Anomalous Star KIC 8462852” (preprint). Previous discussions on this matter can be found in the following reports:

“A Path Forward for Beamed Sails”: https://www.centauri-dreams.org/?p=20962

“Seeing Alien Power Beaming”: https://www.centauri-dreams.org/?p=34133

“Microwave Beaming: A Fast Sail to Mars”: https://www.centauri-dreams.org/?p=1176

“The Case for Beamed Sails”: https://www.centauri-dreams.org/?p=20924

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Comments on this entry are closed.

  • Harry R Ray November 10, 2015, 10:42

    James: I have been EAGERLY AWAITING your take on this subject! “the frequencies we would use for power beaming are in the millimeter band, so are outside the range the Allen Array observed.” Now, I am more confused than ever! It was stated in the recent paper on “lightsail leakage” that the bandwidth would be in the “tens of Gigahertz” range(they even used an EXAMPLE of 68GHz in the paper), but; if we would use the “millimeter band” which telescope would be optimal in the search for “lightsail leakage”? I assume(correct me if I am wrong) that if the “millimeter band” is a LOWER FREQUENCY than the lower limit of 1GHz of the Allen Array, then LOFAR is our best scope. But, if we ARE looking in the “tens of Gigahertz” range, then, Green Bank would be the optimal scope, AFTER the NEW software package is installed sometime(HOPEFULLY)next year. Regardless, I am eagerly awaiting the JVLA observations set for sometime in January, which,hopefully, will include observations of KIC8462852 AND its recently discovered M dwarf BINARY COMPANION! An F3(either at the very end of its stay on the main sequence, or perhaps even in the very early stages of subgianthood) seem to me to be a very low percentage possibility of a star a technically SUPERADVANCED civilization could have originated! . If, however; the M dwarf is a MUCH OLDER STAR, and was captured, say; a billion or so years ago, the percentages would go up DRAMATICALLY. Such a scenario was the BASIS for Brian Aldiss’s famous “Helliconia” series!

  • Black SciFi November 10, 2015, 12:36

    This is a very ambitious and well planned approach for initiating “first contact” with an “ADVANCED” ET civilization.

    Without putting too fine of a point on the “wisdom” of initiating first contact with a technically superior ET civilization, I would ask by what authority our scientists have permission from (UN?, NASA?, Mormons?) to undertake such a potentially dangerous venture?

  • Michael November 10, 2015, 13:27

    @Harry R Ray November 9, 2015 at 10:55

    ‘Correct me if I am wrong, but; if Darth Vader pointed the Death Star at Earth from a distance of 1400 light years and fired its death-ray beam DIRECTLY AT US, I doubt whether ANY of our most sensitive telescopes would detect any photons at all when the beam passes through our solar system!’

    The energy roughly to destroy an earth sized world is ~2.3 x 10 exp 32 J, if the DS was was pointed at us we would see it for sure.

    From the paper

    ‘These limits correspond to isotropic radio transmitter powers of 4 – 7 x 10 exp 15 W and 10 exp 20 W for the narrowband and moderate band observations.’

  • Paul Gilster November 10, 2015, 14:16

    Black SciFi writes:

    Without putting too fine of a point on the “wisdom” of initiating first contact with a technically superior ET civilization, I would ask by what authority our scientists have permission from (UN?, NASA?, Mormons?) to undertake such a potentially dangerous venture?

    This is not a METI effort. The article is in response to a SETI Institute investigation, and the Benfords are quantifying what it might be possible to detect from a star at this distance.

  • Jim Strom November 10, 2015, 15:15

    Thanks for the links.

    Not sure if anyone has computed a hard statistical probability, but wouldn’t the odds of us crossing the path of a powerful beam pushing a light sail be extremely small? The intersection in space and time of a planet and a beam would be an amazing coincidence. Except for possibly an initial “launch” phase of a sail-vehicle out of a local star system, the powering beam would have little movement or arc sweeping. How could (or why would) such a propulsion system operate in any other way than a straight line from source to destination?

    Anti-matter seems like an ideal way to stockpile the power generated by a Dyson structure. Vehicles that carry their own fuel can go anywhere. Aren’t sail-vehicles limited to destinations with decelerator beams? An energy source like anti-matter would be ideal for protecting a planet from celestial objects. Big comet on the way? Hit it with an anti-matter package.

  • ljk November 10, 2015, 15:45

    Should humanity be contacted first by ETI or if we detect them, I predict this is what the response will be from our end:

    https://www.youtube.com/watch?v=rYzc_H9cgqM

    There are terrestrial agencies that want to be the ones in charge should we detect an alien signal or are contacted directly, but there is nothing officially in place yet and if anything should happen any time soon, my prediction is mass chaos.

    I also recommend this book which describes the various plausible contact/detection scenarios and how much we will be affected by them:

    http://www.astrobio.net/topic/deep-space/alien-life/the-seti-factor/

  • Adam November 10, 2015, 16:59

    Just to add some figures to the above discussion. A Jansky is 10^(-26) W/m^2.Hz. Thus 1 Jansky across 100 kHz of bandwidth then means 10^(-21) W of energy is received per square metre of receiver. The distance to Tabby’s Star is 1.4 x 10^19 metres, thus an isotropic signal is spread over ~2.5 x 10^39 m^2. To receive 100 Jansky over a 1 Hz bandwidth requires an isotropic radiator with a power of 2,500 trillion watts. Whether that much power can be radiated over such a narrow bandwidth is a question I leave to the experts.

    The tighter the beam, the less total power that is required to be seen by receivers at our distance, but the odds go down for accidental leakage. A tight power-beam pushing a sail a kilometre square at a range of 1 AU would cover only 10^(-17) of the angular area of the sky. The odds of detection seem terribly unlikely in that case. However, as the paper by Loeb & Guillochon discusses, there are reasons for such beams to scan across small arcs of the sky while lining up with their targets. This increases the odds greatly, though it means the solar system will only be in line very briefly.

  • Harold November 10, 2015, 17:43

    To paraphrase, well maybe butcher, two quotes:

    “you go to [SETI] with the [technology] you have—not the [technology] you might want or wish to have at a later time”

    “we’re gonna need a bigger [telescope]”

  • VL Teofilo November 10, 2015, 17:58

    LM Space Systems Co. performed studies for investment in several Space Based Solar power about 10 yrs ago. All studies concluded that 5.7 GHz microwaves were the preferred transmitting technology since they were 80-90% efficient compared to 30-40% lasers which also had a unacceptable beam divergence from the 17-18 kmi orbit.

  • Dominic Benford November 10, 2015, 23:33

    A quick note to Adam: Yes, your calculations are the right ones to do. The geometry of alignment for a narrow-beam transmission reaching us (a “conjunction”) does reduce the odds of seeing such a transmission in a brief search, but in this case we don’t have to assume that the transmission covers the whole sky. It would be reasonable to posit that the beams will push things around in the plane of the exosolar system, and we already know that we’re closely aligned with that (since we apparently see the occultations of something in the exosolar system passing in front of the star).

  • NS November 11, 2015, 4:48

    My understanding (wrong?) is that one of the criteria for a successful SETI detection is that the signal last long enough for confirmation by different observatories. This seems like something that won’t be possible if the signals we get are (say) from power beams that we intercept only briefly.

    So maybe (on top of looking for anything anomalous) we should be looking for signals that meet most SETI criteria but are of short duration? That would at least give us some places to start.

  • ljk November 11, 2015, 10:40

    NS said on November 11, 2015 at 4:48:

    “My understanding (wrong?) is that one of the criteria for a successful SETI detection is that the signal last long enough for confirmation by different observatories. This seems like something that won’t be possible if the signals we get are (say) from power beams that we intercept only briefly.”

    Yes, this is why the famous Wow! Signal of 1977 is considered by most to be so enigmatic, as it was only detected once despite numerous attempts to find it again after its discovery.

    http://www.bigear.org/wowmenu.htm

    Keep in mind that had the Wow! Signal been detected today it probably would have been rejected as a transmission from ETI, as modern computing technology has found numerous Wow! signals and they have turned out to be terrestrial in nature. In 1977 the detection with OSU’s Big Ear radio telescope was printed out on a sheet of paper and the technician did not note it until hours later. But the legend lives on.

  • ljk November 11, 2015, 10:46

    A planetoid is being ripped apart in an alien star system:

    http://phys.org/news/2015-11-asteroid-ripped-star.html

    Are many similar bodies being treated in a similar fashion in KIC 8675309? I have my doubts but just sayin’ as current humanity is far more comfortable with “conventional” explanations first – as if anything in the Universe is typical for human experience.

  • Alex Tolley November 11, 2015, 13:51

    @Black SciFi, notwithstanding Paul’s response, you are arguing for not making loud noises in the dark, unless presumably, they can be made to seem natural, rather than artificial.

    I we follow this line of thinking (don’t attract predators) we will end up regressing our civilization to the stone age, as we have generated so many signals and biosignatures that advanced aliens can observe. If they have probes monitoring us in the solar system, almost nothing we can do can be hidden. You might as well assume almost omniscient powers of observation.

    I would rather we don’t act so fearful and move forward with our technological advances, which includes beaming power to spacecraft and installations.

  • Michael November 11, 2015, 15:24

    I would be very surprised to have aliens communicating to each other on one frequency or thereabouts. There would most likely be thousands of different frequency’s used negating the need for huge energies which altogether would appears as noise. If they can see us through the gravitation lens of their star they would know we are here. The only time we would ‘see’ them would be if they are communicating directly with us and they would choose a high powered frequency beam. The power requirements of using the gravitational lens would be a lot less than a normal transmission.

  • Adam November 11, 2015, 16:48

    Hi Dominic,
    Good point. Of course, if your dad is right, SETI is looking in the wrong frequency range to see much of anything. Hopefully OSETI has more luck.

  • TLDR November 11, 2015, 17:11

    @ljk: Your assumption is correct, that confirmation depends upon the signal being repeated enough times for more than one observer to record it. That doesn’t mean that “one time only” emissions are always non-ETI sourced. It just means that science cannot confirm it. :)

    By the same token, there is no proof that Wow! was of terrestrial origin. You’d be in the position of trying to prove a negative or something like that.

  • Black SciFi November 11, 2015, 18:26

    @Alex Tolley,
    “notwithstanding Paul’s response, you are arguing for not making loud noises in the dark, unless presumably, they can be made to seem natural, rather than artificial.”

    It is my understanding that RF signals from Earth dissipate with distance and would not be discernible from background radiation/noise before they were close to any close solar system. So, I’m not arguing for a ban on RF.

    I would, however, point out that any ET civilization capable of deep space exploration must have evolved an economy that serves the needs of its population. While those specific economic needs cannot be known, the “Universal Imperative” for life, as we know it or can reasonably speculate about, is: “EVERYTHING HAS TO EAT”.

    There has to be an “end” to developing the” means” of deep space travel.
    I would suggest that end is not research for its own sake.

    My question still stands unanswered. So, for the purpose of my enlightenment: “Are METI projects officially sanctioned by any government or subject to review and control by any national body of elected representatives or a governing body like the United Nation?”

    If not, METI projects are “potentially” very dangerous and those who operate them do so without the consent of those (all human life on this planet) who would be affected by their success.

  • ljk November 12, 2015, 9:51

    Black SciFi said on November 11, 2015 at 18:26:

    “My question still stands unanswered. So, for the purpose of my enlightenment: “Are METI projects officially sanctioned by any government or subject to review and control by any national body of elected representatives or a governing body like the United Nation?”

    In a word, no. There are groups and individuals who want to do this, but that would mean regulating everyone everywhere all the time. If China wanted to use their almost ready giant radio observatory (bigger than Arecibo) to let the rest of the galaxy know they are the new top dog on the block when it comes to radio astronomy – just like Arecibo famously did on November 16, 1974 – who is going to stop them?

    Since trying to get seven billion plus humans to do or agree on anything together borders on the impossible, it may be wiser and more conducive of our time and resources to focus on better understanding the Universe and preparing for the various scenarios of communicating and directly encountering ETI that may arise. We can no longer claim ignorance or special status of our place in the Cosmos, nor can we hide from it. We either accept reality and adjust to it or we will go the way of the dinosaurs.

    Then Black SciFi said:

    “If not, METI projects are “potentially” very dangerous and those who operate them do so without the consent of those (all human life on this planet) who would be affected by their success.”

    You may be surprised at how many groups and individuals do not take the potential for things going south regarding METI. This includes the European Space Agency (ESA), who recently did some METI in tandem with their Rosetta comet mission and dismissed any concerns about a potentially dangerous species detecting their radio transmissions.

  • ljk November 12, 2015, 10:09

    TLDR said on November 11, 2015 at 17:11:

    “@ljk: Your assumption is correct, that confirmation depends upon the signal being repeated enough times for more than one observer to record it. That doesn’t mean that “one time only” emissions are always non-ETI sourced. It just means that science cannot confirm it. :)

    “By the same token, there is no proof that Wow! was of terrestrial origin. You’d be in the position of trying to prove a negative or something like that.”

    While you are correct that I cannot directly prove the Wow! Signal of 1977 was of terrestrial origin, you may want to read what Gerry Harp of The SETI Institute has to say about it here:

    http://phys.org/news/2015-07-aliens-day-nowseti-scientists-discuss.html

    His quote about the Wow! Signal:

    Harp: It isn’t at all special or different from signals that we observe every day at the ATA. I hope you’re not disappointed that I’m not so impressed by the “Wow!” signal. I think you will find that many professional scientists in the field do not find the “Wow!” signal very convincing. But that doesn’t mean that SETI isn’t a good thing to do. There is still a 50% chance, by my estimates, that our first discovery of life off of our planet will be a discovery of a transmitting civilization.

  • Black SciFi November 12, 2015, 11:44

    @IJK,

    The United Nations operates on the principal of providing global oversight, aid and, if necessary, intervention on behalf of its member nations. I would hope that the rumor of UN “First Contact Protocol” being in place would extend in the future to also include mandatory oversight into METI type projects.

    In all honesty I have an optimistic viewpoint regarding the ability of humanity to act in unison to regulate, oversee and intervene to prevent global catastrophe. There are just too many examples of global cooperation. The most recent being the threat of Ebola. I would also include all of the nuclear arms agreements.

    Fortunes are spent on research and preparation for the unknown. The potential for an ELE asteroid or comet strike come to mind. To date, no METI project has the “realistic” technical ability to contact anything.
    To paraphrase my prior comment: ” RF signals dissipate with distance in proportion to signal strength.”

    Until the world is faced with a METI project powered by some version of the LHC, the potential for disaster is unrealistic. When that meta-power threshold is crossed I would hope that common sense would outweigh curiosity.

  • Antonio November 12, 2015, 13:35

    Alex Tolley wrote: “I would rather we don’t act so fearful and move forward with our technological advances, which includes beaming power to spacecraft and installations.”

    Huh? How can that be fearful for ETIs in a distant star but capable os destroying us?

  • ljk November 12, 2015, 15:53

    Black SciFi, it is nice to see your optimism, but now we will see if humanity can live up to it. I think the main reason our planet isn’t a smoldering pile of radioactive rubble is due to sheer luck as much as anything else, with a dash of selfish self-preservation thrown in. And regarding responding to disasters the images and actions of what took place in New Orleans from Hurricane Katrina lo these ten years ago do not invite praise or comfort.

    While there are agencies try to mitigate the threat of an incoming space object, there is nothing seriously in place. The B612 Foundation, as one prime example, recently failed to reach an agreement with NASA as they seem to be more smoke than fire:

    http://nasawatch.com/archives/2015/09/nasa-cancels-sp.html

    We had no warning with the 2013 strike over Russia, which caused big damage and many injuries. If we had some warning we might be able to shoot a few nukes at an incoming space rock – assuming that would not just make the situation worse by spreading out the debris – but at the moment the best we have is a growing early alert system.

  • VL Teofilo November 12, 2015, 17:05

    Getting back to what technology an ET is using or we should be searching for the question is if we are more advanced should we be searching for carrier pigeons or if we are far behind should we be searching for a narrow EM spectra or something humans have yet to conceive. Using the tool developed by an eastern European researcher came up with [see: http://arxiv.org/abs/0707.0011 ] you get a probability of 0.05 for detecting EM signals for 50 yrs of observing which is consistent why SETI has yet to observe anything of value.

  • Alex Tolley November 12, 2015, 18:41

    @Antonio – I am not quite sure what you meant. I look at our situation as an ancient Grecian would the gods on Mt. Olympus. The stories suggest that if you angered the gods, they would harm you, striking you down (e.g. Zeus with lightening bolts). Even technology was frowned upon (Prometheus and fire). So the choice is to be care because you might anger the gods, or ignore them and do what you want. With hindsight the latter choice is obvious.

    Today we have various exrtations not to use certain technologies, not because of the known dangers, but because they are “unnatural”, i.e. our God[s] will punish us for using them. If we use technologies that might signal our presence, that might be bad, and so you have a Fermi Paradox theory that suggests ETI hide, becoming “silent”.

    While we don’t know what is out there, I do think that any very advanced predatory ETI might already know of our existence, simply by local monitoring. If so, why haven’t they destroyed us already? If they are far away, then maybe our best bet is to rapidly develop our technology so that if they detect us in a millenium or so hence, we will have powers that might at least make them think more carefully. If we spread to the stars, even a star killing attack won’t get all of us, leaving them open to possible reprisals. Even humans are careful in the presence of hornet nests. Imagine if nests could communicate?

    We have already started signaling our presence by altering the planetary atmosphere, and strong radio signals have been beamed out as part of our radar tracking operations. We don’t need to add information to indicate we are here and developing technology.

    So bottom line for me is to remain bold, and not to fear a threat that may well not exist.

  • Alex Tolley November 12, 2015, 18:48

    @Black SciFi

    My question still stands unanswered. So, for the purpose of my enlightenment: “Are METI projects officially sanctioned by any government or subject to review and control by any national body of elected representatives or a governing body like the United Nation?”

    If not, METI projects are “potentially” very dangerous and those who operate them do so without the consent of those (all human life on this planet) who would be affected by their success.

    My understanding is that governments have no control. If you have the money and facilities, you can do pretty much what you like. Even if the UN opposed you, how could they sanction you, especially if you were an independent, non UN, territory. e.g. broadcasting from a ship in the open ocean?

    But METI isn’t the only danger. Just sending out strong radio signals from radar is a problem. Just changing the atmosphere is a problem. If there are predators out there, they won’t just be triggered by a METI signal, but will be looking for all sorts of signs of our presence, just as any terrestrial predator does.

  • Black SciFi November 13, 2015, 8:21

    I appreciate commenting on a site where “critical thinking” and “peer review” is treasured as the foundation for the exchange of ideas.

    With that in mind I will again assert that most of the known METI projects are so under powered as to be analogous to “shining a pocket flashlight at the sky” and hoping to get the attention of an ETI.

    If we are to argue the merits of the unrestrained “application” of invention without a moral basis for the use of said “application”, then we must also apply that same logic to an ETI.

    Scientific endeavors that are searching for “life as we know it”, within the context of a meta-powered METI transmission, would seem to be myopic about the consequences of actually finding “life as we know it” that has the required technical superiority to discern a meta-powered METI signal degraded from the gross signal attenuation of traveling multi-AU from its source of origin.

    I do not argue the merits of scientific ignorance. I argue the merits of applying historical wisdom and the responsibility of acknowledging consequences.

  • Antonio November 13, 2015, 16:57

    @Alex Tolley:

    You talked about fear, not anger. I replied to that.

    Anyway, I can’t imagine why they should be affraid or angered against us. And why sending a sail outside our Solar System will cause that fear or anger. It would be like an unknown Amazonian tribe that goes outside the jungle for the first time and then, the Brazilian government, out of fear and rage, drops an atomic bomb and burns that sector of the jungle to ashes.

  • Alex Tolley November 13, 2015, 18:11

    @Antonio – you have it backwards, The fear is on our side, not the ETIs. An argument against METI is that it is like shouting out in the jungle, which will attract a predator. As ETIs are likely far more advanced technologically than we are, that makes it potentially dangerous for us, if you believe that scenario.

  • ljk November 16, 2015, 14:14

    Would a Starshade help us determine what is in the Tabby’s Star system?

    http://www.bbc.com/future/story/20151115-to-find-aliens-we-need-to-build-a-giant-space-parasol?ocid=fbfut

  • Harry R Ray November 20, 2015, 10:52

    I am no longer confused. After further research, I found that the milimeter wave frequency discussed by the Benfords would be used EXCLUSIVELY for LAUNCHES, so that LESS FUEL would be needed, resulting in a much lower mass for the rockets launched. For this scenario to be viable, the launches would have to be from an as yet undiscovered planet, because if you were transporting raw materials from large asteroids or kuiper belt objects to the megastructure, a rail-gun launch appears to me to be much more efficient. THUS: If LOFAR finds this transmission, The likelyhood of a planet STILL EXISTING(i.e. NOT deconstructed to provide raw material to BUILD the megastructure) would increase DRAMATICALLY!

  • ljk November 24, 2015, 18:49

    NASA is leaning towards the safe bet – I mean comets:

    http://www.nasa.gov/feature/jpl/strange-star-likely-swarmed-by-comets